Harden 36_local-bigcrawl per adversarial review

Make the og:image/twitter:image/formaction/ping decoys extensionless so
they stay unfetchable in every aggressive-parser state (today they
survive only because parseall_lastc freezes after the first script tag:
htsparse.c never resets inscript_state_pos on </script>). Close the
audit gaps: pin one per-page image name, forbid unrewritten absolute
hrefs in a tree page, pin the composition of the 4 planted errors, and
bound the mirror size from below (new --min-mirror-bytes audit).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: Xavier Roche <roche@httrack.com>

.gitignore

@@ -39,3 +39,6 @@ Makefile
 
 # Editor / autotools backup files.
 *~
+
+# Python bytecode (tests/local-server.py).
+__pycache__/

src/Makefile.am

@@ -62,7 +62,7 @@ libhttrack_la_SOURCES =  htscore.c htsparse.c htsback.c htscache.c \
 	htsname.c htsrobots.c htstools.c htswizard.c \
 	htsalias.c htsthread.c htsindex.c htsbauth.c \
 	htsmd5.c htszlib.c htswrap.c htsconcat.c \
-	htsmodules.c htscharset.c punycode.c htsencoding.c \
+	htsmodules.c htscharset.c punycode.c htsencoding.c htssniff.c \
 	md5.c \
 	minizip/ioapi.c minizip/mztools.c minizip/unzip.c minizip/zip.c \
 	hts-indextmpl.h htsalias.h htsback.h htsbase.h htssafe.h \
@@ -70,7 +70,7 @@ libhttrack_la_SOURCES =  htscore.c htsparse.c htsback.c htscache.c \
 	htsconfig.h htscore.h htsparse.h htscoremain.h htsdefines.h  \
 	htsfilters.h htsftp.h htsglobal.h htshash.h coucal/coucal.h \
 	htshelp.h htsindex.h htslib.h htsmd5.h \
-	htsmodules.h htsname.h htsnet.h \
+	htsmodules.h htsname.h htsnet.h htssniff.h \
 	htsopt.h htsrobots.h htsthread.h  \
 	htstools.h htswizard.h htswrap.h htszlib.h  \
 	htsstrings.h htsarrays.h httrack-library.h \

src/htsback.c

@@ -1359,6 +1359,18 @@ int back_flush_output(httrackp * opt, cache_back * cache, struct_back * sback,
 }
 
 // effacer entrée
+/* Discard a cancelled mid-write .delayed placeholder (unusable across runs). */
+static void back_delayed_discard(httrackp *opt, lien_back *back) {
+  if (back->r.out != NULL) {
+    fclose(back->r.out);
+    back->r.out = NULL;
+  }
+  back->r.is_write = 0;
+  if (opt != NULL)
+    url_savename_refname_remove(opt, back->url_adr, back->url_fil);
+  (void) UNLINK(back->url_sav);
+}
+
 int back_delete(httrackp * opt, cache_back * cache, struct_back * sback,
                 const int p) {
   lien_back *const back = sback->lnk;
@@ -1366,6 +1378,12 @@ int back_delete(httrackp * opt, cache_back * cache, struct_back * sback,
 
   assertf(p >= 0 && p < back_max);
   if (p >= 0 && p < sback->count) {     // on sait jamais..
+    /* mid-write cancel: drop a .delayed placeholder; real-named partials
+       survive for resume (--continue) */
+    if (back[p].r.is_write && IS_DELAYED_EXT(back[p].url_sav) &&
+        (back[p].status != STATUS_READY || back[p].r.statuscode <= 0)) {
+      back_delayed_discard(opt, &back[p]);
+    }
     // Vérificateur d'intégrité
 #if DEBUG_CHECKINT
     _CHECKINT(&back[p], "Appel back_delete")
@@ -2419,6 +2437,34 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
   back_clean(opt, cache, sback);
 #endif
 
+  /* Time limit exceeded past grace: abort in-flight transfers so no wait loop
+     starves (#481). FTP slots stay, their thread owns the socket. */
+  if (!back_checkmirror(opt)) {
+    int aborted = 0;
+    unsigned int i;
+
+    for (i = 0; i < (unsigned int) back_max; i++) {
+      if (back[i].status > 0 && back[i].status < STATUS_FTP_TRANSFER) {
+        if (back[i].r.soc != INVALID_SOCKET) {
+          deletehttp(&back[i].r);
+        }
+        back[i].r.soc = INVALID_SOCKET;
+        /* drop a .delayed placeholder; real partials survive for resume */
+        if (back[i].r.is_write && IS_DELAYED_EXT(back[i].url_sav))
+          back_delayed_discard(opt, &back[i]);
+        back[i].r.statuscode = STATUSCODE_TIMEOUT;
+        strcpybuff(back[i].r.msg, "Mirror Time Out");
+        back[i].status = STATUS_READY;
+        back_set_finished(sback, i);
+        aborted++;
+      }
+    }
+    if (aborted > 0)
+      hts_log_print(opt, LOG_WARNING,
+                    "time limit reached, %d transfer(s) aborted", aborted);
+    return;
+  }
+
   // recevoir tant qu'il y a des données (avec un maximum de max_loop boucles)
   do_wait = 0;
   gestion_timeout = 0;
@@ -4164,6 +4210,11 @@ int back_checksize(httrackp * opt, lien_back * eback, int check_only_totalsize)
   return 1;
 }
 
+/* Grace left to the smooth stop before in-flight transfers are aborted. */
+static int back_maxtime_grace(const int maxtime) {
+  return maximum(5, minimum(30, maxtime / 10));
+}
+
 int back_checkmirror(httrackp * opt) {
   // Check max size
   if ((opt->maxsite > 0) && (HTS_STAT.stat_bytes >= opt->maxsite)) {
@@ -4180,13 +4231,19 @@ int back_checkmirror(httrackp * opt) {
      */
   }
   // Check max time
-  if ((opt->maxtime > 0)
-      && ((time_local() - HTS_STAT.stat_timestart) >= opt->maxtime)) {
-    if (!opt->state.stop) {     /* not yet stopped */
-      hts_log_print(opt, LOG_ERROR, "More than %d seconds passed.. giving up",
-                    opt->maxtime);
-      /* cancel mirror smoothly */
-      hts_request_stop(opt, 0);
+  if (opt->maxtime > 0) {
+    const TStamp elapsed = time_local() - HTS_STAT.stat_timestart;
+
+    if (elapsed >= opt->maxtime) {
+      if (!opt->state.stop) { /* not yet stopped */
+        hts_log_print(opt, LOG_ERROR, "More than %d seconds passed.. giving up",
+                      opt->maxtime);
+        /* cancel mirror smoothly */
+        hts_request_stop(opt, 0);
+      }
+      /* smooth stop starved past the grace period: stop waiting (#481) */
+      if (elapsed - opt->maxtime >= back_maxtime_grace(opt->maxtime))
+        return 0;
     }
   }
   return 1;                     /* Ok, go on */

src/htsback.h

@@ -136,6 +136,8 @@ void back_solve(httrackp * opt, lien_back * sback);
 int host_wait(httrackp * opt, lien_back * sback);
 #endif
 int back_checksize(httrackp * opt, lien_back * eback, int check_only_totalsize);
+/* Enforce -M/-E quotas: requests a smooth stop when reached; returns 0 once
+   the -E deadline overran its grace period (callers must stop waiting). */
 int back_checkmirror(httrackp * opt);
 
 #endif

src/htscache.c

@@ -596,15 +596,18 @@ htsblk cache_read_ro(httrackp * opt, cache_back * cache, const char *adr,
   return cache_readex(opt, cache, adr, fil, save, location, NULL, 1);
 }
 
-htsblk cache_read_including_broken(httrackp * opt, cache_back * cache,
-                                   const char *adr, const char *fil) {
-  htsblk r = cache_read(opt, cache, adr, fil, NULL, NULL);
+htsblk cache_read_including_broken(httrackp *opt, cache_back *cache,
+                                   const char *adr, const char *fil,
+                                   char *return_save) {
+  htsblk r = cache_readex(opt, cache, adr, fil, NULL, NULL, return_save, 0);
 
   if (r.statuscode == -1) {
     lien_back *itemback = NULL;
 
     if (back_unserialize_ref(opt, adr, fil, &itemback) == 0) {
       r = itemback->r;
+      if (return_save != NULL)
+        strlcpybuff(return_save, itemback->url_sav, HTS_URLMAXSIZE * 2);
       /* cleanup */
       back_clear_entry(itemback);       /* delete entry content */
       freet(itemback);          /* delete item */

src/htscache.h

@@ -66,8 +66,11 @@ htsblk cache_read(httrackp * opt, cache_back * cache, const char *adr,
                   const char *fil, const char *save, char *location);
 htsblk cache_read_ro(httrackp * opt, cache_back * cache, const char *adr,
                      const char *fil, const char *save, char *location);
-htsblk cache_read_including_broken(httrackp * opt, cache_back * cache,
-                                   const char *adr, const char *fil);
+/* Like cache_read, but also yields entries whose transfer broke; return_save
+   (optional, HTS_URLMAXSIZE*2) receives the entry's recorded save name. */
+htsblk cache_read_including_broken(httrackp *opt, cache_back *cache,
+                                   const char *adr, const char *fil,
+                                   char *return_save);
 htsblk cache_readex(httrackp * opt, cache_back * cache, const char *adr,
                     const char *fil, const char *save, char *location,
                     char *return_save, int readonly);

src/htscore.c

@@ -3371,6 +3371,41 @@ int back_pluggable_sockets_strict(struct_back * sback, httrackp * opt) {
   return n;
 }
 
+/* One engine-loop tick: refresh the transfer stats and run the loop callback
+   for slot b (-1 = none). HTS_FALSE = the callback requested an abort. */
+hts_boolean hts_loop_tick(struct_back *sback, httrackp *opt, int b, int ptr) {
+  engine_stats();
+  HTS_STAT.stat_nsocket = back_nsoc(sback);
+  HTS_STAT.stat_errors = fspc(opt, NULL, "error");
+  HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
+  HTS_STAT.stat_infos = fspc(opt, NULL, "info");
+  HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
+  HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
+  return RUN_CALLBACK7(
+             opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
+             (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)
+             ? HTS_TRUE
+             : HTS_FALSE;
+}
+
+/* Single implementation of the historical WAIT_FOR_AVAILABLE_SOCKET macros. */
+hts_boolean hts_wait_available_socket(struct_back *sback, httrackp *opt,
+                                      cache_back *cache, int ptr) {
+  const int prev = opt->state._hts_in_html_parsing;
+
+  while (back_pluggable_sockets_strict(sback, opt) <= 0) {
+    opt->state._hts_in_html_parsing = 6;
+    back_wait(sback, opt, cache, 0);
+    /* time limit (-E) exceeded: stop waiting for a socket (#481) */
+    if (!back_checkmirror(opt))
+      break;
+    if (!hts_loop_tick(sback, opt, -1, ptr))
+      return HTS_FALSE;
+  }
+  opt->state._hts_in_html_parsing = prev;
+  return HTS_TRUE;
+}
+
 int back_pluggable_sockets(struct_back * sback, httrackp * opt) {
   int n;
 

src/htscore.h

@@ -432,6 +432,15 @@ int back_pluggable_sockets(struct_back * sback, httrackp * opt);
 
 int back_pluggable_sockets_strict(struct_back * sback, httrackp * opt);
 
+/* One engine-loop tick: refresh the transfer stats and run the loop callback
+   for slot b (-1 = none). HTS_FALSE = the callback requested an abort. */
+hts_boolean hts_loop_tick(struct_back *sback, httrackp *opt, int b, int ptr);
+
+/* Wait until a test socket can be plugged, pumping transfers, stats and the
+   loop callback; gives up past the -E deadline. HTS_FALSE = callback abort. */
+hts_boolean hts_wait_available_socket(struct_back *sback, httrackp *opt,
+                                      cache_back *cache, int ptr);
+
 /* Randomized inter-file pause target in [min_ms,max_ms] (#185), derived from a
    timestamp seed so it is stable within one gap and rerolls per launch. */
 int hts_pause_target_ms(TStamp seed, int min_ms, int max_ms);

src/htsname.c

@@ -41,6 +41,10 @@ Please visit our Website: http://www.httrack.com
 #include "htstools.h"
 #include "htscharset.h"
 #include "htsencoding.h"
+#include "htssniff.h"
+#if HTS_USEZLIB
+#include "htszlib.h"
+#endif
 #include <ctype.h>
 
 #define ADD_STANDARD_PATH \
@@ -70,31 +74,6 @@ static const char *hts_tbdev[] = {
   ""
 };
 
-#define URLSAVENAME_WAIT_FOR_AVAILABLE_SOCKET() do { \
-  int prev = opt->state._hts_in_html_parsing; \
-  while(back_pluggable_sockets_strict(sback, opt) <= 0) { \
-    opt->state. _hts_in_html_parsing = 6; \
-    /* Wait .. */ \
-    back_wait(sback,opt,cache,0); \
-    /* Transfer rate */ \
-    engine_stats(); \
-    /* Refresh various stats */ \
-    HTS_STAT.stat_nsocket=back_nsoc(sback); \
-    HTS_STAT.stat_errors=fspc(opt,NULL,"error"); \
-    HTS_STAT.stat_warnings=fspc(opt,NULL,"warning"); \
-    HTS_STAT.stat_infos=fspc(opt,NULL,"info"); \
-    HTS_STAT.nbk=backlinks_done(sback,opt->liens,opt->lien_tot,ptr); \
-    HTS_STAT.nb=back_transferred(HTS_STAT.stat_bytes,sback); \
-    /* Check */ \
-    { \
-      if (!RUN_CALLBACK7(opt, loop, sback->lnk, sback->count,-1,ptr,opt->lien_tot,(int) (time_local()-HTS_STAT.stat_timestart),&HTS_STAT)) { \
-        return -1; \
-      } \
-    } \
-  } \
-  opt->state._hts_in_html_parsing = prev; \
-} while(0)
-
 /* Strip all // */
 static void cleanDoubleSlash(char *s) {
   int i, j;
@@ -138,46 +117,184 @@ static void cleanEndingSpaceOrDot(char *s) {
   }
 }
 
-/* Should the wire Content-Type override the URL's own extension when naming the
-   saved file? True when the type is patchable (may_unknown2) and either the URL
-   extension implies no specific type or the server declared a disagreeing one.
-   A URL extension mapping to a specific non-HTML type is kept only when the
-   server declared NO type (the HTS_UNKNOWN_MIME sentinel; the #267 mangle
-   guard): a typeless .png stays .png, but a .pdf explicitly served as text/html
-   is named .html. The sentinel rides the cache, so updates stay consistent. */
-static int wire_patches_ext(httrackp *opt, const char *wiremime,
-                            const char *file) {
-  char urlmime[256];
+/* Wire Content-Type vs URL extension: a patchable wire type wins over an
+   unspecific ext, the HTS_UNKNOWN_MIME sentinel keeps a specific non-HTML ext
+   (#267 guard), a declared disagreement is CONTESTED (sniffed below). */
+typedef enum wire_verdict {
+  WIRE_KEEPS_EXT,
+  WIRE_WINS,
+  WIRE_CONTESTED
+} wire_verdict;
 
+static wire_verdict wire_ext_verdict(httrackp *opt, const char *wiremime,
+                                     const char *file, char *urlmime,
+                                     size_t urlmime_size) {
   if (may_unknown2(opt, wiremime, file))
-    return 0; /* type kept verbatim (keep-list / bogus-multiple) */
+    return WIRE_KEEPS_EXT; /* type kept verbatim (keep-list / bogus-multiple) */
   urlmime[0] = '\0';
   /* type implied by the URL extension, only when confidently known (flag 0) */
-  if (!get_httptype_sized(opt, urlmime, sizeof(urlmime), file, 0))
-    return 1; /* URL ext implies no known type: trust the wire type */
+  if (!get_httptype_sized(opt, urlmime, urlmime_size, file, 0))
+    return WIRE_WINS; /* URL ext implies no known type */
   if (strfield2(wiremime, urlmime))
-    return 0; /* wire agrees with the ext: keep it (no .htm->.html churn) */
-  /* wire disagrees with a specific non-HTML URL ext. Keep the ext only when
-     the server declared no type (the sentinel); an explicitly declared type,
-     even text/html, is trusted, so a binary-looking URL that really serves
-     HTML (login/error interstitial, soft-404) is named .html. */
+    return WIRE_KEEPS_EXT; /* agreement (no .htm->.html churn) */
   if (!is_hypertext_mime(opt, urlmime, file) &&
       strfield2(wiremime, HTS_UNKNOWN_MIME))
+    return WIRE_KEEPS_EXT; /* no declared type */
+  return WIRE_CONTESTED;
+}
+
+/* Optional evidence for a contested wire-vs-ext verdict. */
+typedef struct sniff_src {
+  struct_back *sback;       /* live backing (looked up by adr/fil) */
+  const lien_back *headers; /* snapshot: r.adr, else the url_sav file */
+  const char *adr, *fil;
+  const char *prev_save; /* previous run's save name (cache X-Save) */
+} sniff_src;
+
+#if HTS_USEZLIB
+/* Inflate the head of a gzip/zlib stream; 0 when undecodable. */
+static size_t sniff_inflate_head(const void *in, size_t in_len, void *out,
+                                 size_t out_len) {
+  z_stream zs;
+  size_t n = 0;
+  int err;
+
+  memset(&zs, 0, sizeof(zs));
+  if (inflateInit2(&zs, 47) != Z_OK) /* 47: gzip or zlib, autodetected */
     return 0;
+  zs.next_in = (const Bytef *) in;
+  zs.avail_in = (uInt) in_len;
+  zs.next_out = (Bytef *) out;
+  zs.avail_out = (uInt) out_len;
+  err = inflate(&zs, Z_SYNC_FLUSH);
+  if (err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR)
+    n = out_len - zs.avail_out;
+  inflateEnd(&zs);
+  return n;
+}
+#endif
+
+static size_t sniff_read_head(const char *path, void *buf, size_t len) {
+  char catbuff[CATBUFF_SIZE];
+  FILE *const fp = FOPEN(fconv(catbuff, sizeof(catbuff), path), "rb");
+  size_t n = 0;
+
+  if (fp != NULL) {
+    n = fread(buf, 1, len, fp);
+    fclose(fp);
+  }
+  return n;
+}
+
+/* Body head of one slot: memory, else its flushed on-disk file (url_sav, or
+   tmpfile for a compressed stream); inflated so the sniff sees the final body.
+ */
+static size_t sniff_slot_head(const lien_back *slot, void *buf, size_t len) {
+  const htsblk *const r = &slot->r;
+  size_t n = 0;
+
+  if (r->adr != NULL && r->size > 0) {
+    n = (size_t) r->size < len ? (size_t) r->size : len;
+    memcpy(buf, r->adr, n);
+  } else {
+    if (r->out != NULL)
+      fflush(r->out);
+    if (slot->url_sav[0] != '\0')
+      n = sniff_read_head(slot->url_sav, buf, len);
+    if (n == 0 && slot->tmpfile != NULL && slot->tmpfile[0] != '\0')
+      n = sniff_read_head(slot->tmpfile, buf, len);
+  }
+  if (n > 0 && r->compressed) {
+#if HTS_USEZLIB
+    unsigned char raw[HTS_SNIFF_LEN];
+
+    if (n > sizeof(raw))
+      n = sizeof(raw);
+    memcpy(raw, buf, n);
+    n = sniff_inflate_head(raw, n, buf, len);
+#else
+    n = 0;
+#endif
+  }
+  return n;
+}
+
+/* Up to len leading body bytes; 0 when unavailable, and always in
+   non-delayed mode (its HEAD-probe first run couldn't sniff either). */
+static size_t sniff_body_head(httrackp *opt, const sniff_src *src, void *buf,
+                              size_t len) {
+  size_t n = 0;
+
+  if (src == NULL || opt->savename_delayed == HTS_SAVENAME_DELAYED_NONE)
+    return 0;
+  /* live backing slot: a snapshot (back_copy_static) loses r.adr/r.out */
+  if (src->sback != NULL && src->adr != NULL && src->fil != NULL) {
+    const int b = back_index(opt, src->sback, src->adr, src->fil, NULL);
+
+    if (b >= 0)
+      n = sniff_slot_head(&src->sback->lnk[b], buf, len);
+  }
+  if (n == 0 && src->headers != NULL)
+    n = sniff_slot_head(src->headers, buf, len);
+  return n;
+}
+
+/* Contested verdicts: magic proving the URL ext keeps it, else wire wins. */
+static int wire_patches_ext(httrackp *opt, const sniff_src *src,
+                            const char *wiremime, const char *file) {
+  char urlmime[256];
+
+  switch (wire_ext_verdict(opt, wiremime, file, urlmime, sizeof(urlmime))) {
+  case WIRE_KEEPS_EXT:
+    return 0;
+  case WIRE_WINS:
+    return 1;
+  case WIRE_CONTESTED:
+    break;
+  }
+  if (src != NULL) {
+    if (hts_sniff_mime_known(urlmime)) {
+      unsigned char head[HTS_SNIFF_LEN];
+      const size_t n = sniff_body_head(opt, src, head, sizeof(head));
+
+      if (n > 0)
+        return hts_sniff_mime_consistent(head, n, urlmime) ? 0 : 1;
+    }
+    /* no bytes: reproduce the previous run's verdict (cached X-Save name) */
+    if (src->prev_save != NULL && src->prev_save[0] != '\0') {
+      char prevmime[256];
+
+      prevmime[0] = '\0';
+      if (get_httptype_sized(opt, prevmime, sizeof(prevmime), src->prev_save,
+                             0) &&
+          strfield2(prevmime, urlmime))
+        return 0;
+    }
+  }
   return 1;
 }
 
+int hts_ext_sniff_wanted(httrackp *opt, const char *wiremime,
+                         const char *file) {
+  char urlmime[256];
+
+  return wiremime != NULL && strnotempty(wiremime) &&
+         wire_ext_verdict(opt, wiremime, file, urlmime, sizeof(urlmime)) ==
+             WIRE_CONTESTED &&
+         hts_sniff_mime_known(urlmime);
+}
+
 /* Wire-metadata name change: a Content-Disposition filename wins (returns 2),
    else the declared type's ext when wire_patches_ext() allows (returns 1),
    else 0. ext receives the new extension or replacement filename. */
-static int resolve_extension(httrackp *opt, const char *cdispo,
-                             const char *contenttype, const char *fil,
-                             char *ext, size_t ext_size) {
+static int resolve_extension(httrackp *opt, const sniff_src *src,
+                             const char *cdispo, const char *contenttype,
+                             const char *fil, char *ext, size_t ext_size) {
   if (strnotempty(cdispo)) {
     strlcpybuff(ext, cdispo, ext_size);
     return 2;
   }
-  if (wire_patches_ext(opt, contenttype, fil) &&
+  if (wire_patches_ext(opt, src, contenttype, fil) &&
       give_mimext(ext, ext_size, contenttype))
     return 1;
   return 0;
@@ -429,14 +546,21 @@ int url_savename(lien_adrfilsave *const afs,
         if (opt->savename_delayed == HTS_SAVENAME_DELAYED_HARD ||
             ishtml(opt, fil) < 0) { // unsure whether it's html or a file
           // lire dans le cache
-          htsblk r = cache_read_including_broken(opt, cache, adr, fil); // test uniquement
+          char BIGSTK previous_save[HTS_URLMAXSIZE * 2];
+          htsblk r;
+
+          previous_save[0] = '\0';
+          r = cache_read_including_broken(opt, cache, adr, fil,
+                                          previous_save); // test uniquement
 
           if (r.statuscode != -1) { // cache entry read OK
             hts_log_print(opt, LOG_DEBUG, "Testing link type (from cache) %s%s",
                           adr_complete, fil_complete);
             if (!HTTP_IS_REDIRECT(r.statuscode)) {
-              ext_chg = resolve_extension(opt, r.cdispo, r.contenttype, fil,
-                                          ext, sizeof(ext));
+              const sniff_src src = {sback, NULL, adr, fil, previous_save};
+
+              ext_chg = resolve_extension(opt, &src, r.cdispo, r.contenttype,
+                                          fil, ext, sizeof(ext));
             }
           } else if (opt->savename_delayed != HTS_SAVENAME_DELAYED_HARD &&
                      is_userknowntype(opt, fil)) { /* PATCH BY BRIAN SCHRÖDER.
@@ -463,7 +587,9 @@ int url_savename(lien_adrfilsave *const afs,
                    !opt->state.stop) {
             // Check if the file is ready in backing.
             if (headers != NULL && headers->status >= 0 && !is_redirect) {
-              ext_chg = resolve_extension(opt, headers->r.cdispo,
+              const sniff_src src = {sback, headers, adr, fil, NULL};
+
+              ext_chg = resolve_extension(opt, &src, headers->r.cdispo,
                                           headers->r.contenttype,
                                           headers->url_fil, ext, sizeof(ext));
             }
@@ -501,11 +627,10 @@ int url_savename(lien_adrfilsave *const afs,
             int has_been_moved = 0;
             lien_adrfil current;
 
-            /* Ensure we don't use too many sockets by using a "testing" one
-               If we have only 1 simultaneous connection authorized, wait for pending download
-               Wait for an available slot 
+            /* Wait for an available test slot, honoring the connection limits
              */
-            URLSAVENAME_WAIT_FOR_AVAILABLE_SOCKET();
+            if (!hts_wait_available_socket(sback, opt, cache, ptr))
+              return -1;
 
             /* Rock'in */
             current.adr[0] = current.fil[0] = '\0';
@@ -535,24 +660,11 @@ int url_savename(lien_adrfilsave *const afs,
                   if (ptr >= 0) {
                     back_fillmax(sback, opt, cache, ptr, numero_passe);
                   }
-                  // on est obligé d'appeler le shell pour le refresh..
-                  // Transfer rate
-                  engine_stats();
-
-                  // Refresh various stats
-                  HTS_STAT.stat_nsocket = back_nsoc(sback);
-                  HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-                  HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-                  HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-                  HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-                  HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
-                  if (!RUN_CALLBACK7
-                      (opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
-                       (int) (time_local() - HTS_STAT.stat_timestart),
-                       &HTS_STAT)) {
+                  if (!hts_loop_tick(sback, opt, b, ptr)) {
                     return -1;
-                  } else if (opt->state._hts_cancel || !back_checkmirror(opt)) {        // cancel 2 ou 1 (cancel parsing)
+                  } else if (opt->state._hts_cancel ||
+                             !back_checkmirror(
+                                 opt)) { // cancel level 2 or 1 (cancel parsing)
                     back_delete(opt, cache, sback, b);  // cancel test
                     stop_looping = 1;
                   }
@@ -617,8 +729,9 @@ int url_savename(lien_adrfilsave *const afs,
                                                 "Loop with HEAD request (during prefetch) at %s%s",
                                                 current.adr, current.fil);
                                 }
-                                // Ajouter
-                                URLSAVENAME_WAIT_FOR_AVAILABLE_SOCKET();
+                                if (!hts_wait_available_socket(sback, opt,
+                                                               cache, ptr))
+                                  return -1;
                                 if (back_add(sback, opt, cache, moved.adr, moved.fil, methode, referer_adr, referer_fil, 1) != -1) {        // OK
                                   hts_log_print(opt, LOG_DEBUG,
                                                 "(during prefetch) %s (%d) to link %s at %s%s",
@@ -674,7 +787,7 @@ int url_savename(lien_adrfilsave *const afs,
 
                   // no error: change the type?
                   ext_chg = resolve_extension(
-                      opt, back[b].r.cdispo, back[b].r.contenttype,
+                      opt, NULL, back[b].r.cdispo, back[b].r.contenttype,
                       back[b].url_fil, ext, sizeof(ext));
                 }
                 // FIN Si non déplacé, forcer type?

src/htsname.h

@@ -100,6 +100,8 @@ void standard_name(char *b, size_t bsize, const char *dot_pos,
                    const char *nom_pos, const char *fil_complete,
                    int short_ver);
 void url_savename_addstr(char *d, const char *s);
+/* Contested wire-vs-ext verdict that a body sniff could settle (htssniff.h). */
+int hts_ext_sniff_wanted(httrackp *opt, const char *wiremime, const char *file);
 char *url_md5(char *digest_buffer, const char *fil_complete);
 void url_savename_refname(const char *adr, const char *fil, char *filename);
 char *url_savename_refname_fullpath(httrackp * opt, const char *adr,

src/htsparse.c

@@ -49,6 +49,7 @@ Please visit our Website: http://www.httrack.com
 #include "htsindex.h"
 #include "htscharset.h"
 #include "htsencoding.h"
+#include "htssniff.h"
 
 /* external modules */
 #include "htsmodules.h"
@@ -3398,20 +3399,7 @@ int htsparse(htsmoduleStruct * str, htsmoduleStructExtended * stre) {
           back_wait(sback, opt, cache, HTS_STAT.stat_timestart);
           back_fillmax(sback, opt, cache, ptr, numero_passe);
 
-          // Transfer rate
-          engine_stats();
-
-          // Refresh various stats
-          HTS_STAT.stat_nsocket = back_nsoc(sback);
-          HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-          HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-          HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-          HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-          HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
-          if (!RUN_CALLBACK7
-              (opt, loop, sback->lnk, sback->count, 0, ptr, opt->lien_tot,
-               (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)) {
+          if (!hts_loop_tick(sback, opt, 0, ptr)) {
             hts_log_print(opt, LOG_ERROR, "Exit requested by shell or user");
             *stre->exit_xh_ = 1;        // exit requested
             XH_uninit;
@@ -3422,7 +3410,6 @@ int htsparse(htsmoduleStruct * str, htsmoduleStructExtended * stre) {
             nofollow = 1;       // moins violent
             opt->state._hts_cancel = 0;
           }
-
         }
         // refresh the backing system each 2 seconds
         if (engine_stats()) {
@@ -3959,22 +3946,8 @@ void hts_mirror_process_user_interaction(htsmoduleStruct * str,
         {
           back_wait(sback, opt, cache, HTS_STAT.stat_timestart);
 
-          // Transfer rate
-          engine_stats();
-
-          // Refresh various stats
-          HTS_STAT.stat_nsocket = back_nsoc(sback);
-          HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-          HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-          HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-          HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-          HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
           b = 0;
-          if (!RUN_CALLBACK7
-              (opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
-               (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)
-              || !back_checkmirror(opt)) {
+          if (!hts_loop_tick(sback, opt, b, ptr) || !back_checkmirror(opt)) {
             hts_log_print(opt, LOG_ERROR, "Exit requested by shell or user");
             *stre->exit_xh_ = 1;        // exit requested
             XH_uninit;
@@ -4076,21 +4049,11 @@ void hts_mirror_process_user_interaction(htsmoduleStruct * str,
     while(opt->state._hts_setpause || back_pluggable_sockets_strict(sback, opt) <= 0) { // on fait la pause..
       opt->state._hts_in_html_parsing = 6;
       back_wait(sback, opt, cache, HTS_STAT.stat_timestart);
+      /* time limit (-E) exceeded: stop waiting for a socket (#481) */
+      if (!back_checkmirror(opt))
+        break;
 
-      // Transfer rate
-      engine_stats();
-
-      // Refresh various stats
-      HTS_STAT.stat_nsocket = back_nsoc(sback);
-      HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-      HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-      HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-      HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-      HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
-      if (!RUN_CALLBACK7
-          (opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
-           (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)) {
+      if (!hts_loop_tick(sback, opt, b, ptr)) {
         hts_log_print(opt, LOG_ERROR, "Exit requested by shell or user");
         *stre->exit_xh_ = 1;    // exit requested
         XH_uninit;
@@ -4277,26 +4240,12 @@ int hts_mirror_wait_for_next_file(htsmoduleStruct * str,
           freet(s);
         }
 
-        // Transfer rate
-        engine_stats();
-
-        // Refresh various stats
-        HTS_STAT.stat_nsocket = back_nsoc(sback);
-        HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-        HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-        HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-        HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-        HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
-        if (!RUN_CALLBACK7
-            (opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
-             (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)) {
+        if (!hts_loop_tick(sback, opt, b, ptr)) {
           hts_log_print(opt, LOG_ERROR, "Exit requested by shell or user");
           *stre->exit_xh_ = 1;  // exit requested
           XH_uninit;
           return 0;
         }
-
       }
 
 #if HTS_POLL
@@ -4529,10 +4478,9 @@ int hts_wait_delayed(htsmoduleStruct * str, lien_adrfilsave *afs,
         IS_DELAYED_EXT(afs->save) && continue_loop && loops < 7; loops++) {
       continue_loop = 0;
 
-      /*
-         Wait for an available slot 
-       */
-      WAIT_FOR_AVAILABLE_SOCKET();
+      /* Wait for an available slot */
+      if (!hts_wait_available_socket(sback, opt, cache, ptr))
+        return -1;
 
       /* We can lookup directly in the cache to speedup this mess */
       if (opt->delayed_cached) {
@@ -4678,39 +4626,28 @@ int hts_wait_delayed(htsmoduleStruct * str, lien_adrfilsave *afs,
           if (ptr >= 0) {
             back_fillmax(sback, opt, cache, ptr, numero_passe);
           }
-          // on est obligé d'appeler le shell pour le refresh..
-          {
-
-            // Transfer rate
-            engine_stats();
-
-            // Refresh various stats
-            HTS_STAT.stat_nsocket = back_nsoc(sback);
-            HTS_STAT.stat_errors = fspc(opt, NULL, "error");
-            HTS_STAT.stat_warnings = fspc(opt, NULL, "warning");
-            HTS_STAT.stat_infos = fspc(opt, NULL, "info");
-            HTS_STAT.nbk = backlinks_done(sback, opt->liens, opt->lien_tot, ptr);
-            HTS_STAT.nb = back_transferred(HTS_STAT.stat_bytes, sback);
-
-            if (!RUN_CALLBACK7
-                (opt, loop, sback->lnk, sback->count, b, ptr, opt->lien_tot,
-                 (int) (time_local() - HTS_STAT.stat_timestart), &HTS_STAT)) {
-              return -1;
-            } else if (opt->state._hts_cancel || !back_checkmirror(opt)) {      // cancel 2 ou 1 (cancel parsing)
-              back_delete(opt, cache, sback, b);        // cancel test
-              break;
-            }
+          if (!hts_loop_tick(sback, opt, b, ptr)) {
+            back_set_unlocked(sback, b);
+            return -1;
+          } else if (opt->state._hts_cancel ||
+                     !back_checkmirror(
+                         opt)) { // cancel level 2 or 1 (cancel parsing)
+            back_delete(opt, cache, sback, b); // cancel test
+            break;
           }
-        } while(
-                 /* dns/connect/request */
-                 (back[b].status >= 99 && back[b].status <= 101)
-                 ||
-                 /* For redirects, wait for request to be terminated */
-                 (HTTP_IS_REDIRECT(back[b].r.statuscode) && back[b].status > 0)
-                 ||
-                 /* Same for errors */
-                 (HTTP_IS_ERROR(back[b].r.statuscode) && back[b].status > 0)
-          );
+        } while (
+            /* dns/connect/request */
+            (back[b].status >= 99 && back[b].status <= 101) ||
+            /* For redirects, wait for request to be terminated */
+            (HTTP_IS_REDIRECT(back[b].r.statuscode) && back[b].status > 0) ||
+            /* Same for errors */
+            (HTTP_IS_ERROR(back[b].r.statuscode) && back[b].status > 0) ||
+            /* Contested type: wait for a sniffable body head (or EOF) */
+            (back[b].r.statuscode == HTTP_OK && back[b].status > 0 &&
+             strnotempty(back[b].r.cdispo) == 0 &&
+             back[b].r.size < HTS_SNIFF_LEN &&
+             hts_ext_sniff_wanted(opt, back[b].r.contenttype,
+                                  back[b].url_fil)));
         if (b >= 0) {
           back_set_unlocked(sback, b);  // Unlocked entry
         }
@@ -4845,8 +4782,8 @@ int hts_wait_delayed(htsmoduleStruct * str, lien_adrfilsave *afs,
 
           /* Still have a back reference */
           if (b >= 0) {
-            /* Patch destination filename for direct-to-disk mode, BEFORE any
-               finalize: it records and caches the entry under url_sav */
+            /* patch url_sav BEFORE finalize: it records/caches under this name
+             */
             strcpybuff(back[b].url_sav, afs->save);
             /* Finalize now as we have the type */
             if (back[b].status == STATUS_READY) {

src/htsparse.h

@@ -175,27 +175,4 @@ int hts_wait_delayed(htsmoduleStruct * str, lien_adrfilsave *afs,
   /* Apply changes */ \
   * str->ptr_ = ptr
 
-#define WAIT_FOR_AVAILABLE_SOCKET() do { \
-  int prev = opt->state._hts_in_html_parsing; \
-  while(back_pluggable_sockets_strict(sback, opt) <= 0) { \
-    opt->state._hts_in_html_parsing = 6; \
-    /* Wait .. */ \
-    back_wait(sback,opt,cache,0); \
-    /* Transfer rate */ \
-    engine_stats(); \
-    /* Refresh various stats */ \
-    HTS_STAT.stat_nsocket=back_nsoc(sback); \
-    HTS_STAT.stat_errors=fspc(opt,NULL,"error"); \
-    HTS_STAT.stat_warnings=fspc(opt,NULL,"warning"); \
-    HTS_STAT.stat_infos=fspc(opt,NULL,"info"); \
-    HTS_STAT.nbk=backlinks_done(sback,opt->liens,opt->lien_tot,ptr); \
-    HTS_STAT.nb=back_transferred(HTS_STAT.stat_bytes,sback); \
-    /* Check */ \
-    if (!RUN_CALLBACK7(opt, loop, sback->lnk, sback->count, -1,ptr,opt->lien_tot,(int) (time_local()-HTS_STAT.stat_timestart),&HTS_STAT)) { \
-      return -1; \
-    } \
-  } \
-  opt->state._hts_in_html_parsing = prev; \
-} while(0)
-
 #endif

src/htsselftest.c

@@ -52,6 +52,7 @@ Please visit our Website: http://www.httrack.com
 #include "htsencoding.h"
 #include "htsftp.h"
 #include "htsmd5.h"
+#include "htssniff.h"
 #if HTS_USEZLIB
 #include "htszlib.h"
 #endif
@@ -1117,6 +1118,46 @@ static int st_header(httrackp *opt, int argc, char **argv) {
   return 0;
 }
 
+/* Decode a body argument ("hex:FFD8.." or literal text) into buf. */
+static size_t st_decode_body(const char *arg, char *buf, size_t size) {
+  size_t n = 0;
+
+  if (strncmp(arg, "hex:", 4) == 0) {
+    const char *s = arg + 4;
+
+    for (; s[0] != '\0' && s[1] != '\0' && n + 1 < size; s += 2) {
+      unsigned int byte;
+
+      if (sscanf(s, "%2x", &byte) != 1)
+        break;
+      buf[n++] = (char) byte;
+    }
+  } else {
+    n = strlen(arg);
+    if (n >= size)
+      n = size - 1;
+    memcpy(buf, arg, n);
+  }
+  buf[n] = '\0';
+  return n;
+}
+
+static int st_sniff(httrackp *opt, int argc, char **argv) {
+  char BIGSTK body[1024];
+  size_t n;
+
+  (void) opt;
+  if (argc < 2) {
+    fprintf(stderr, "sniff: needs a content-type and a body\n");
+    return 1;
+  }
+  n = st_decode_body(argv[1], body, sizeof(body));
+  printf("sniff: known=%d consistent=%d\n",
+         hts_sniff_mime_known(argv[0]) == HTS_TRUE,
+         hts_sniff_mime_consistent(body, n, argv[0]) == HTS_TRUE);
+  return 0;
+}
+
 static int st_savename(httrackp *opt, int argc, char **argv) {
   lien_adrfilsave afs;
   cache_back cache;
@@ -1125,6 +1166,9 @@ static int st_savename(httrackp *opt, int argc, char **argv) {
   lien_back headers;
   const char *adr = "www.example.com";
   const char *cdispo = NULL;
+  const char *body = NULL;
+  const char *cached = NULL;
+  const char *bodyfile = "st-savename-body.tmp";
   int statuscode = HTTP_OK, status = 0;
   int i;
 
@@ -1158,6 +1202,10 @@ static int st_savename(httrackp *opt, int argc, char **argv) {
       opt->savename_83 = atoi(a + 4);
     else if (strncmp(a, "type=", 5) == 0)
       opt->savename_type = atoi(a + 5);
+    else if (strncmp(a, "body=", 5) == 0)
+      body = a + 5;
+    else if (strncmp(a, "cached=", 7) == 0)
+      cached = a + 7;
     else if (strncmp(a, "prior=", 6) != 0) {
       fprintf(stderr, "savename: unknown arg '%s'\n", a);
       return 1;
@@ -1168,7 +1216,47 @@ static int st_savename(httrackp *opt, int argc, char **argv) {
   strcpybuff(afs.af.fil, argv[0]);
 
   memset(&cache, 0, sizeof(cache));
-  cache.hashtable = (void *) coucal_new(0);
+  if (cached != NULL) { /* cached=<content-type>|<save name> */
+    char *dup = strdupt(cached);
+    char *const sep = strchr(dup, '|');
+    char locbuf[64] = "";
+    htsblk cr;
+
+    if (sep == NULL) {
+      fprintf(stderr, "savename: cached needs ctype|save\n");
+      return 1;
+    }
+    *sep = '\0';
+    /* one-entry cache in cwd, reopened read-only; body is PNG magic on
+       purpose: only the recorded name (X-Save) may drive the naming */
+    StringCopy(opt->path_log, "");
+    cache.type = 1;
+    cache.log = cache.errlog = stderr;
+    cache.hashtable = coucal_new(0);
+    cache_init(&cache, opt);
+    hts_init_htsblk(&cr);
+    cr.statuscode = HTTP_OK;
+    strcpybuff(cr.msg, "OK");
+    strcpybuff(cr.contenttype, dup);
+    cr.location = locbuf;
+    cr.adr = strdupt("\x89PNG\r\n\x1a\n");
+    cr.size = 8;
+    cache_add(opt, &cache, &cr, adr, argv[0], sep + 1, 1, NULL);
+    freet(cr.adr);
+    if (cache.zipOutput != NULL) {
+      zipClose(cache.zipOutput, NULL);
+      cache.zipOutput = NULL;
+    }
+    memset(&cache, 0, sizeof(cache));
+    cache.type = 1;
+    cache.log = cache.errlog = stderr;
+    cache.hashtable = coucal_new(0);
+    cache.ro = 1;
+    cache_init(&cache, opt);
+    freet(dup);
+  } else {
+    cache.hashtable = (void *) coucal_new(0);
+  }
 
   sback = back_new(opt, opt->maxsoc * 32 + 1024);
   /* same wiring as hts_mirror (htscore.c) */
@@ -1201,9 +1289,23 @@ static int st_savename(httrackp *opt, int argc, char **argv) {
   if (cdispo != NULL)
     strcpybuff(headers.r.cdispo, cdispo);
   strcpybuff(headers.url_fil, argv[0]);
+  if (body != NULL) { /* leading body bytes, read via url_sav */
+    char BIGSTK data[1024];
+    const size_t n = st_decode_body(body, data, sizeof(data));
+    FILE *const fp = fopen(bodyfile, "wb");
+
+    if (fp == NULL || fwrite(data, 1, n, fp) != n) {
+      fprintf(stderr, "savename: can not write %s\n", bodyfile);
+      return 1;
+    }
+    fclose(fp);
+    strcpybuff(headers.url_sav, bodyfile);
+  }
 
   url_savename(&afs, NULL, NULL, NULL, opt, sback, &cache, &hash, 0, 0,
                &headers);
+  if (body != NULL)
+    (void) UNLINK(bodyfile);
   printf("savename: %s\n", afs.save);
   return 0;
 }
@@ -2010,6 +2112,8 @@ static const struct selftest_entry {
      st_header},
     {"savename", "<fil> <content-type> [key=value ...]",
      "local save-name for a URL", st_savename},
+    {"sniff", "<content-type> <hex:..|text>", "MIME magic consistency",
+     st_sniff},
     {"cache", "<dir>", "cache read/write round-trip self-test", st_cache},
     {"cache-golden", "<dir> [regen]", "frozen cache-format read self-test",
      st_cache_golden},

src/htssniff.c

@@ -0,0 +1,352 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 1998-2017 Xavier Roche and other contributors
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Important notes:
+
+- We hereby ask people using this source NOT to use it in purpose of grabbing
+emails addresses, or collecting any other private information on persons.
+This would disgrace our work, and spoil the many hours we spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: MIME magic-byte consistency checks                     */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+#include "htssniff.h"
+
+#include <string.h>
+
+#include "htslib.h"
+
+/* One magic rule: `len` bytes at `off` confirm `mime`. */
+typedef struct sniff_magic {
+  const char *mime;
+  unsigned short off;
+  unsigned char len;
+  const char *bytes;
+} sniff_magic;
+
+/* Direction is mime -> magic (verify a claim, never classify); types with
+   no reliable magic (plain text, css, js..) are deliberately absent. Patterns
+   follow the WHATWG MIME Sniffing Standard tables where it defines them
+   (https://mimesniff.spec.whatwg.org/); the rest covers httrack's wider MIME
+   set. Spec-only types absent from our MIME tables (EOT, font/collection)
+   are omitted as unreachable. */
+static const sniff_magic sniff_table[] = {
+    /* images */
+    {"image/jpeg", 0, 3, "\xff\xd8\xff"},
+    {"image/pipeg", 0, 3, "\xff\xd8\xff"},
+    {"image/pjpeg", 0, 3, "\xff\xd8\xff"},
+    {"image/png", 0, 8, "\x89PNG\r\n\x1a\n"},
+    {"image/gif", 0, 6, "GIF87a"},
+    {"image/gif", 0, 6, "GIF89a"},
+    {"image/bmp", 0, 2, "BM"},
+    {"image/tiff", 0, 4, "II*\0"},
+    {"image/tiff", 0, 4, "MM\0*"},
+    {"image/x-icon", 0, 4, "\0\0\1\0"},
+    {"image/x-icon", 0, 4, "\0\0\2\0"}, /* Windows cursor, per the spec */
+    {"image/x-portable-bitmap", 0, 2, "P1"},
+    {"image/x-portable-bitmap", 0, 2, "P4"},
+    {"image/x-portable-pixmap", 0, 2, "P3"},
+    {"image/x-portable-pixmap", 0, 2, "P6"},
+    {"image/x-xpixmap", 0, 9, "/* XPM */"},
+    {"image/x-xbitmap", 0, 7, "#define"},
+    {"image/x-rgb", 0, 2, "\x01\xda"},
+    {"image/x-cmu-raster", 0, 4, "\xf1\x00\x40\xbb"},
+    /* audio */
+    {"audio/mpeg", 0, 3, "ID3"},
+    {"audio/basic", 0, 4, ".snd"},
+    {"audio/mid", 0, 8, "MThd\0\0\0\6"},
+    {"audio/midi", 0, 8, "MThd\0\0\0\6"},
+    {"audio/x-pn-realaudio", 0, 4, ".ra\xfd"},
+    {"audio/x-pn-realaudio", 0, 4, ".RMF"},
+    {"audio/x-pn-realaudio-plugin", 0, 4, ".ra\xfd"},
+    {"audio/x-pn-realaudio-plugin", 0, 4, ".RMF"},
+    {"audio/flac", 0, 4, "fLaC"},
+    {"audio/aac", 0, 4, "ADIF"},
+    /* video */
+    {"video/mpeg", 0, 4, "\x00\x00\x01\xba"},
+    {"video/mpeg", 0, 4, "\x00\x00\x01\xb3"},
+    {"video/x-sgi-movie", 0, 4, "MOVI"},
+    /* archives / compression */
+    {"application/x-gzip", 0, 3, "\x1f\x8b\x08"},
+    {"multipart/x-gzip", 0, 3, "\x1f\x8b\x08"},
+    {"application/x-compressed", 0, 3, "\x1f\x8b\x08"},
+    {"application/x-compress", 0, 2, "\x1f\x9d"},
+    {"application/x-bzip2", 0, 3, "BZh"},
+    {"application/x-7z-compressed", 0, 6, "7z\xbc\xaf\x27\x1c"},
+    /* 6-byte prefix common to RAR4 (spec) and RAR5 */
+    {"application/x-rar-compressed", 0, 6, "Rar!\x1a\x07"},
+    {"application/zstd", 0, 4, "\x28\xb5\x2f\xfd"},
+    {"application/arj", 0, 2, "\x60\xea"},
+    {"application/x-cpio", 0, 6, "070701"},
+    {"application/x-cpio", 0, 6, "070707"},
+    {"application/x-cpio", 0, 2, "\xc7\x71"},
+    {"application/x-sv4cpio", 0, 6, "070701"},
+    {"application/x-sv4crc", 0, 6, "070702"},
+    {"application/x-stuffit", 0, 8, "StuffIt "},
+    {"application/x-stuffit", 0, 4, "SIT!"},
+    {"application/mac-binhex40", 0, 10, "(This file"},
+    /* documents */
+    {"application/pdf", 0, 5, "%PDF-"},
+    {"application/postscript", 0, 2, "%!"},
+    {"application/rtf", 0, 5, "{\\rtf"},
+    {"application/x-dvi", 0, 2, "\xf7\x02"},
+    {"application/x-hdf", 0, 4, "\x0e\x03\x13\x01"},
+    {"application/x-hdf", 0, 8, "\x89HDF\r\n\x1a\n"},
+    {"application/x-netcdf", 0, 4, "CDF\x01"},
+    {"application/x-netcdf", 0, 4, "CDF\x02"},
+    {"application/x-msaccess", 0, 19, "\0\1\0\0Standard Jet DB"},
+    /* fonts */
+    {"font/woff", 0, 4, "wOFF"},
+    {"font/woff2", 0, 4, "wOF2"},
+    {"font/ttf", 0, 4, "\0\1\0\0"},
+    {"font/ttf", 0, 4, "true"},
+    {"font/otf", 0, 4, "OTTO"},
+    /* misc */
+    {"application/x-shockwave-flash", 0, 3, "FWS"},
+    {"application/x-shockwave-flash", 0, 3, "CWS"},
+    {"application/x-shockwave-flash", 0, 3, "ZWS"},
+    {"application/futuresplash", 0, 3, "FWS"},
+    {"application/x-director", 0, 4, "RIFX"},
+    {"application/x-director", 0, 4, "XFIR"},
+    {"application/x-java-vm", 0, 4, "\xca\xfe\xba\xbe"},
+    {"application/wasm", 0, 4, "\0asm"},
+    {"application/x-msmetafile", 0, 4, "\xd7\xcd\xc6\x9a"},
+    {"application/x-msmetafile", 0, 4, "\x01\x00\x09\x00"},
+    {"application/x-x509-ca-cert", 0, 2, "\x30\x82"},
+    {"application/x-pkcs12", 0, 2, "\x30\x82"},
+    {"application/x-pkcs7-mime", 0, 2, "\x30\x82"},
+    {"application/x-pkcs7-signature", 0, 2, "\x30\x82"},
+    {"application/x-pkcs7-certificates", 0, 2, "\x30\x82"},
+    {"x-world/x-vrml", 0, 5, "#VRML"},
+    {"application/x-bittorrent", 0, 11, "d8:announce"},
+    {"drawing/x-dwf", 0, 4, "(DWF"},
+    {"application/acad", 0, 4, "AC10"},
+    {NULL, 0, 0, NULL}};
+
+/* MIME families sharing a container magic */
+static const char *const zip_mimes[] = {
+    "application/zip", "application/x-zip-compressed", "multipart/x-zip", NULL};
+static const char *const zip_mime_prefixes[] = {
+    "application/vnd.openxmlformats-officedocument.",
+    "application/vnd.oasis.opendocument.", NULL};
+static const char *const ole_mimes[] = {"application/msword",
+                                        "application/excel",
+                                        "application/vnd.ms-excel",
+                                        "application/powerpoint",
+                                        "application/vnd.ms-powerpoint",
+                                        "application/vnd.ms-project",
+                                        "application/vnd.ms-works",
+                                        "application/x-msmoney",
+                                        "application/x-mspublisher",
+                                        NULL};
+static const char *const tar_mimes[] = {
+    "application/x-tar", "application/x-ustar", "application/x-gtar", NULL};
+static const char *const ogg_mimes[] = {"application/ogg", "audio/ogg",
+                                        "video/ogg", "audio/opus", NULL};
+static const char *const ebml_mimes[] = {"video/webm", "audio/webm", NULL};
+/* ISO-BMFF, any 'ftyp' brand: containers overlap too much to split */
+static const char *const bmff_mimes[] = {"video/mp4", "audio/mp4",
+                                         "video/quicktime", NULL};
+static const char *const avif_mimes[] = {"image/avif", NULL};
+static const char *const heic_mimes[] = {"image/heic", NULL};
+static const char *const asf_mimes[] = {"video/x-ms-asf", "video/x-ms-wmv",
+                                        "video/x-la-asf", NULL};
+static const char *const xml_mimes[] = {"application/xml", "text/xml",
+                                        "image/svg+xml", "image/svg-xml", NULL};
+static const char *const svg_mimes[] = {"image/svg+xml", "image/svg-xml", NULL};
+static const char *const html_mimes[] = {"text/html", NULL};
+static const char *const pem_mimes[] = {
+    "application/x-x509-ca-cert", "application/x-pkcs7-certificates",
+    "application/x-pkcs7-mime", "application/x-pkcs7-signature", NULL};
+
+static hts_boolean mime_in(const char *const *list, const char *mime) {
+  size_t i;
+
+  for (i = 0; list[i] != NULL; i++)
+    if (strfield2(list[i], mime))
+      return HTS_TRUE;
+  return HTS_FALSE;
+}
+
+static hts_boolean mime_in_prefix(const char *const *list, const char *mime) {
+  size_t i;
+
+  for (i = 0; list[i] != NULL; i++)
+    if (strfield(mime, list[i]))
+      return HTS_TRUE;
+  return HTS_FALSE;
+}
+
+static hts_boolean has_bytes(const unsigned char *d, size_t n, size_t off,
+                             const char *bytes, size_t len) {
+  /* overflow-safe: untrusted n alone on one side */
+  return n >= off && len <= n - off && memcmp(d + off, bytes, len) == 0
+             ? HTS_TRUE
+             : HTS_FALSE;
+}
+
+static unsigned char ascii_lower(unsigned char c) {
+  return c >= 'A' && c <= 'Z' ? (unsigned char) (c + 32) : c;
+}
+
+/* Case-insensitive text prefix after an optional UTF-8 BOM and whitespace. */
+static hts_boolean has_text_prefix(const unsigned char *d, size_t n,
+                                   const char *prefix) {
+  const size_t len = strlen(prefix);
+  size_t i, k;
+
+  i = n >= 3 && memcmp(d, "\xef\xbb\xbf", 3) == 0 ? 3 : 0;
+  while (i < n && (d[i] == ' ' || d[i] == '\t' || d[i] == '\r' || d[i] == '\n'))
+    i++;
+  if (len > n - i) /* i <= n from the loop above */
+    return HTS_FALSE;
+  for (k = 0; k < len; k++)
+    if (ascii_lower(d[i + k]) != ascii_lower((unsigned char) prefix[k]))
+      return HTS_FALSE;
+  return HTS_TRUE;
+}
+
+typedef enum sniff_op {
+  SNIFF_QUERY_KNOWN, /* is any rule defined for this MIME? */
+  SNIFF_QUERY_MATCH  /* do the bytes confirm this MIME? */
+} sniff_op;
+
+/* Single walk for both queries so the rule set can't drift apart. */
+static hts_boolean sniff_eval(sniff_op op, const unsigned char *d, size_t n,
+                              const char *mime) {
+  size_t i;
+
+/* KNOWN short-circuits; MATCH tests the magic */
+#define SNIFF_RULE(cond)                                                       \
+  do {                                                                         \
+    if (op == SNIFF_QUERY_KNOWN)                                               \
+      return HTS_TRUE;                                                         \
+    if (cond)                                                                  \
+      return HTS_TRUE;                                                         \
+  } while (0)
+
+  for (i = 0; sniff_table[i].mime != NULL; i++) {
+    if (strfield2(sniff_table[i].mime, mime)) {
+      SNIFF_RULE(has_bytes(d, n, sniff_table[i].off, sniff_table[i].bytes,
+                           sniff_table[i].len));
+    }
+  }
+  if (mime_in(zip_mimes, mime) || mime_in_prefix(zip_mime_prefixes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "PK\3\4", 4) ||
+               has_bytes(d, n, 0, "PK\5\6", 4));
+  }
+  if (mime_in(ole_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1", 8));
+  }
+  if (mime_in(tar_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 257, "ustar", 5));
+  }
+  if (mime_in(ogg_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "OggS\0", 5));
+  }
+  if (mime_in(ebml_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "\x1a\x45\xdf\xa3", 4));
+  }
+  if (mime_in(bmff_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 4, "ftyp", 4));
+  }
+  if (mime_in(avif_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 4, "ftypavif", 8) ||
+               has_bytes(d, n, 4, "ftypavis", 8));
+  }
+  if (mime_in(heic_mimes, mime)) {
+    SNIFF_RULE(
+        has_bytes(d, n, 4, "ftyphei", 7) || has_bytes(d, n, 4, "ftyphev", 7) ||
+        has_bytes(d, n, 4, "ftypmif1", 8) || has_bytes(d, n, 4, "ftypmsf1", 8));
+  }
+  if (mime_in(asf_mimes, mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "\x30\x26\xb2\x75\x8e\x66\xcf\x11", 8));
+  }
+  if (strfield2("audio/x-wav", mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "RIFF", 4) && has_bytes(d, n, 8, "WAVE", 4));
+  }
+  if (strfield2("video/x-msvideo", mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "RIFF", 4) && has_bytes(d, n, 8, "AVI ", 4));
+  }
+  if (strfield2("image/webp", mime)) {
+    SNIFF_RULE(has_bytes(d, n, 0, "RIFF", 4) &&
+               has_bytes(d, n, 8, "WEBPVP", 6));
+  }
+  if (strfield2("image/x-portable-anymap", mime)) {
+    SNIFF_RULE(n >= 2 && d[0] == 'P' && d[1] >= '1' && d[1] <= '6');
+  }
+  if (strfield2("audio/x-aiff", mime)) {
+    SNIFF_RULE(
+        has_bytes(d, n, 0, "FORM", 4) &&
+        (has_bytes(d, n, 8, "AIFF", 4) || has_bytes(d, n, 8, "AIFC", 4)));
+  }
+  if (strfield2("audio/mpeg", mime)) {
+    /* MPEG audio frame sync (11 bits), valid layer and bitrate fields */
+    SNIFF_RULE(n >= 2 && d[0] == 0xff && (d[1] & 0xe0) == 0xe0 &&
+               (d[1] & 0x06) != 0);
+  }
+  if (strfield2("audio/aac", mime)) {
+    /* ADTS sync */
+    SNIFF_RULE(n >= 2 && d[0] == 0xff && (d[1] & 0xf6) == 0xf0);
+  }
+  if (strfield2("video/mp2t", mime)) {
+    SNIFF_RULE(n >= 1 && d[0] == 0x47 && (n <= 188 || d[188] == 0x47));
+  }
+  if (mime_in(xml_mimes, mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "<?xml"));
+  }
+  if (mime_in(svg_mimes, mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "<svg") ||
+               has_text_prefix(d, n, "<!DOCTYPE svg"));
+  }
+  if (mime_in(html_mimes, mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "<!DOCTYPE") ||
+               has_text_prefix(d, n, "<html") ||
+               has_text_prefix(d, n, "<head"));
+  }
+  if (mime_in(pem_mimes, mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "-----BEGIN"));
+  }
+  if (strfield2("audio/x-mpegurl", mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "#EXTM3U"));
+  }
+  if (strfield2("text/x-vcard", mime)) {
+    SNIFF_RULE(has_text_prefix(d, n, "BEGIN:VCARD"));
+  }
+#undef SNIFF_RULE
+  return HTS_FALSE;
+}
+
+hts_boolean hts_sniff_mime_known(const char *mime) {
+  if (mime == NULL || *mime == '\0')
+    return HTS_FALSE;
+  return sniff_eval(SNIFF_QUERY_KNOWN, NULL, 0, mime);
+}
+
+hts_boolean hts_sniff_mime_consistent(const void *data, size_t size,
+                                      const char *mime) {
+  if (data == NULL || size == 0 || mime == NULL || *mime == '\0')
+    return HTS_FALSE;
+  return sniff_eval(SNIFF_QUERY_MATCH, (const unsigned char *) data, size,
+                    mime);
+}

src/htssniff.h

@@ -0,0 +1,50 @@
+/* ------------------------------------------------------------ */
+/*
+HTTrack Website Copier, Offline Browser for Windows and Unix
+Copyright (C) 1998-2017 Xavier Roche and other contributors
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+Important notes:
+
+- We hereby ask people using this source NOT to use it in purpose of grabbing
+emails addresses, or collecting any other private information on persons.
+This would disgrace our work, and spoil the many hours we spent on it.
+
+Please visit our Website: http://www.httrack.com
+*/
+
+/* ------------------------------------------------------------ */
+/* File: MIME magic-byte consistency checks                     */
+/* Author: Xavier Roche                                         */
+/* ------------------------------------------------------------ */
+
+#ifndef HTSSNIFF_DEFH
+#define HTSSNIFF_DEFH
+
+#include <stddef.h>
+#include "htsglobal.h"
+
+/* Leading-body window read to arbitrate a wire/extension MIME conflict. */
+#define HTS_SNIFF_LEN 512
+
+/* Can a magic rule ever confirm this MIME? (whether sniffing is worth it) */
+hts_boolean hts_sniff_mime_known(const char *mime);
+
+/* TRUE when the leading body bytes are consistent with the claimed MIME;
+   FALSE on unknown MIME, unknown magic, or too-short data (fail-safe). */
+hts_boolean hts_sniff_mime_consistent(const void *data, size_t size,
+                                      const char *mime);
+
+#endif

tests/01_engine-savename.test

@@ -7,8 +7,16 @@ set -euo pipefail
 # name() asserts on the basename, full() on the whole path; prior= registers an
 # already-crawled link whose sav is rooted under the -O path (/dev/null here).
 
+# resolve httrack before cd: make check puts a RELATIVE ../src on PATH
+httrack_bin=$(cd "$(dirname "$(command -v httrack)")" && pwd)/httrack
+
+# scratch dir: body= and cached= write temp files (st-savename-body.tmp, hts-cache/)
+scratch=$(mktemp -d)
+trap 'rm -rf "$scratch"' EXIT
+cd "$scratch"
+
 run() {
-    httrack -O /dev/null -#test=savename "$@" | sed -n 's/^savename: //p'
+    "$httrack_bin" -O /dev/null -#test=savename "$@" | sed -n 's/^savename: //p'
 }
 
 name() {
@@ -73,6 +81,15 @@ name '/x.pdf' 'text/html' 'x.html' status=-1
 name '/x.html' 'text/html' 'x.html' status=-1
 name '/x.php' 'application/pdf' 'x.pdf' status=-1 cdispo=report.pdf
 
+# Contested type (wire disagrees with a specific ext): magic bytes proving the
+# extension right keep it, anything else trusts the wire as before.
+name '/photo.jpg' 'image/png' 'photo.jpg' body=hex:FFD8FFE000104A46
+name '/photo.jpg' 'image/png' 'photo.png' body=hex:89504E470D0A1A0A
+name '/photo.jpg' 'image/png' 'photo.png'
+name '/doc.pdf' 'text/html' 'doc.pdf' body=hex:255044462D312E34
+name '/doc.pdf' 'text/html' 'doc.html' 'body=<html><body>soft 404</body></html>'
+name '/style.css' 'image/png' 'style.png' 'body=body { }' # no rule for css: wire wins
+
 # A redirect answer resolves nothing: delayed placeholder name.
 name '/x.php' 'text/html' 'x.0.delayed' statuscode=301
 

tests/01_engine-sniff.test

@@ -0,0 +1,87 @@
+#!/bin/bash
+#
+
+set -euo pipefail
+
+# MIME magic consistency (-#test=sniff <content-type> <hex:..|text>), the
+# tie-break behind htsname's wire-vs-extension naming.
+
+chk() {
+    local mime="$1" body="$2" want="$3"
+    out="$(httrack -#test=sniff "$mime" "$body" | sed -n 's/^sniff: //p')"
+    test "$out" == "$want" || {
+        echo "FAIL: '$mime' '$body' -> '$out' (want '$want')"
+        exit 1
+    }
+}
+
+yes='known=1 consistent=1'
+no='known=1 consistent=0'
+unk='known=0 consistent=0'
+
+# images
+chk image/jpeg hex:FFD8FFE000104A46 "$yes"
+chk image/png hex:89504E470D0A1A0A "$yes"
+chk image/png hex:FFD8FFE000104A46 "$no" # jpeg bytes are not a png
+chk image/gif 'GIF89a' "$yes"
+chk image/bmp 'BMxxxx' "$yes"
+chk image/tiff hex:49492A00 "$yes"
+chk image/tiff hex:4D4D002A "$yes" # both endians
+chk image/x-icon hex:00000100 "$yes"
+chk image/x-icon hex:00000200 "$yes" # Windows cursor, spec maps to x-icon
+chk image/webp 'RIFFxxxxWEBPVP' "$yes"
+chk image/webp 'RIFFxxxxWAVE' "$no" # riff subtype discriminates
+chk image/avif hex:0000001C6674797061766966 "$yes"
+chk image/avif hex:0000001C6674797068656963 "$no" # heic brand is not avif
+chk image/heic hex:0000001C6674797068656963 "$yes"
+chk image/svg+xml '<svg xmlns="x">' "$yes"
+chk image/svg+xml $'\xef\xbb\xbf  <?xml version="1.0"?>' "$yes" # BOM+ws skip
+
+# audio / video
+chk audio/mpeg 'ID3xxx' "$yes"
+chk audio/mpeg hex:FFFB9000 "$yes" # bare frame sync
+chk audio/aac hex:FFF15080 "$yes"
+chk audio/flac 'fLaC' "$yes"
+chk audio/ogg hex:4F67675300 "$yes"
+chk audio/x-wav 'RIFFxxxxWAVE' "$yes"
+chk video/x-msvideo 'RIFFxxxxAVI ' "$yes"
+chk video/x-msvideo 'RIFFxxxxWAVE' "$no"
+chk video/mp4 hex:000000186674797069736F6D "$yes"
+chk video/webm hex:1A45DFA3 "$yes"
+chk video/mpeg hex:000001BA "$yes"
+chk video/x-ms-wmv hex:3026B2758E66CF11 "$yes"
+
+# archives; zip magic covers the office-container families
+chk application/zip hex:504B0304 "$yes"
+chk application/vnd.openxmlformats-officedocument.wordprocessingml.document hex:504B0304 "$yes"
+chk application/vnd.oasis.opendocument.text hex:504B0304 "$yes"
+chk application/msword hex:D0CF11E0A1B11AE1 "$yes"
+chk application/msword hex:504B0304 "$no" # legacy .doc is OLE, not zip
+chk application/x-gzip hex:1F8B08 "$yes"
+chk application/x-bzip2 'BZh9' "$yes"
+chk application/x-7z-compressed hex:377ABCAF271C "$yes"
+chk application/x-rar-compressed hex:526172211A07 "$yes"
+chk application/zstd hex:28B52FFD "$yes"
+chk application/x-tar "hex:$(printf '00%.0s' {1..257})7573746172" "$yes" # ustar at 257
+chk application/x-tar hex:7573746172 "$no"
+
+# documents, fonts, misc
+chk application/pdf '%PDF-1.7' "$yes"
+chk application/pdf '<html><body>soft 404</body></html>' "$no"
+chk application/postscript '%!PS-Adobe' "$yes"
+chk application/rtf '{\rtf1' "$yes"
+chk font/woff2 'wOF2' "$yes"
+chk font/otf 'OTTO' "$yes"
+chk font/ttf hex:0001000000 "$yes"
+chk application/x-shockwave-flash 'CWSx' "$yes"
+chk application/x-java-vm hex:CAFEBABE "$yes"
+chk application/wasm hex:0061736D "$yes"
+chk text/html $'  \r\n<!DOCTYPE html><html>' "$yes"
+chk text/html '<html lang="en">' "$yes"
+chk text/html 'plain text, no markup' "$no"
+chk text/xml '<?xml version="1.0"?>' "$yes"
+
+# no magic rule at all: never confirmed, never blocks the wire type
+chk text/css 'body { }' "$unk"
+chk text/plain 'hello' "$unk"
+chk application/x-javascript 'var x;' "$unk"

tests/01_zlib-savename-cached.test

@@ -0,0 +1,33 @@
+#!/bin/bash
+#
+
+set -euo pipefail
+
+# Update-run naming from a real cache entry (-#test=savename cached=<ctype>|<save>).
+# Named 01_zlib-*: the cache writer needs zlib, which the MSan job can't run.
+
+# resolve httrack before cd: make check puts a RELATIVE ../src on PATH
+httrack_bin=$(cd "$(dirname "$(command -v httrack)")" && pwd)/httrack
+
+scratch=$(mktemp -d)
+trap 'rm -rf "$scratch"' EXIT
+cd "$scratch"
+
+name() {
+    local fil="$1" ctype="$2" want="$3"
+    shift 3
+    out="$("$httrack_bin" -O /dev/null -#test=savename "$fil" "$ctype" "$@" | sed -n 's/^savename: //p')"
+    test "${out##*/}" == "$want" || {
+        echo "FAIL: '$fil' '$ctype' $* -> '$out' (want '$want')"
+        exit 1
+    }
+}
+
+# No live bytes: the recorded save name (X-Save) reproduces the previous
+# verdict; cached body bytes (PNG magic) are ignored; css has no magic rule.
+name '/photo.jpg' 'image/png' 'photo.jpg' 'cached=image/png|www.example.com/photo.jpg'
+name '/photo.jpg' 'image/png' 'photo.png' 'cached=image/png|www.example.com/photo.png'
+name '/photo.jpg' 'image/jpeg' 'photo.jpg' 'cached=image/jpeg|www.example.com/photo.png'
+name '/style.css' 'image/png' 'style.css' 'cached=image/png|www.example.com/style.css'
+# agreement keeps the URL ext verbatim (.jpeg), never canonicalized to .jpg
+name '/photo.jpeg' 'image/jpeg' 'photo.jpeg' 'cached=image/jpeg|www.example.com/photo.jpeg'

tests/15_local-types.test

@@ -1,11 +1,10 @@
 #!/bin/bash
 #
-# Content-Type vs URL-extension naming (issue #267 family) under the default
-# delayed type check (-%N2). Policy: a MISSING Content-Type must not clobber a
-# URL extension that maps to a specific non-HTML type (.png/.pdf stay as-is);
-# an explicitly DECLARED type is trusted, so a binary-looking URL that really
-# serves HTML (text/html on .pdf/.jpg) is named .html. The "wrong" names are
-# asserted absent so a regression in either direction fails here.
+# Content-Type vs URL-extension naming (#267 family, default -%N2). A MISSING
+# type keeps a specific non-HTML ext; a DECLARED disagreeing type is trusted
+# unless magic bytes prove the ext right (lie/wrongtype/packed keep theirs),
+# so a real HTML body (report.pdf) still becomes .html. Wrong names are
+# asserted absent so a regression in either direction fails.
 
 : "${top_srcdir:=..}"
 
@@ -14,7 +13,11 @@ bash "$top_srcdir/tests/local-crawl.sh" --errors 0 \
     --found 'types/notype.pdf' --not-found 'types/notype.html' \
     --found 'types/photo.png' \
     --found 'types/doc.pdf' \
-    --found 'types/lie.html' --not-found 'types/lie.png' \
+    --found 'types/lie.png' --not-found 'types/lie.html' \
+    --found 'types/wrongtype.jpg' --not-found 'types/wrongtype.png' \
+    --found 'types/bigtype.jpg' --not-found 'types/bigtype.png' \
+    --found 'types/mutant.jpg' --not-found 'types/mutant.png' \
+    --found 'types/packed.jpg' --not-found 'types/packed.png' \
     --found 'types/report.html' --not-found 'types/report.pdf' \
     --found 'types/page.htm' --not-found 'types/page.html' \
     --found 'types/script.js' \

tests/18_local-update.test

@@ -1,15 +1,18 @@
 #!/bin/bash
 #
-# A second (update) pass must keep the names the first crawl chose. The stored
-# Content-Type rides the cache, so the update reads back the same value -- the
-# unknown/unknown sentinel for a typeless response, the declared type otherwise
-# -- and names consistently: a declared-text/html .pdf stays .html and a
-# typeless .png stays .png across the update rather than reverting.
+# An update pass keeps the names the first crawl chose: type and save name
+# ride the cache, so a declared-text/html .pdf stays .html, a typeless .png
+# stays .png, and a sniff-kept ext is reproduced from X-Save even when the
+# refetched content changed (mutant.jpg serves PNG bytes on the rerun).
 
 : "${top_srcdir:=..}"
 
 bash "$top_srcdir/tests/local-crawl.sh" --errors 0 --rerun \
     --found 'types/report.html' --not-found 'types/report.pdf' \
     --found 'types/notype.png' --not-found 'types/notype.html' \
-    --found 'types/lie.html' \
+    --found 'types/lie.png' --not-found 'types/lie.html' \
+    --found 'types/wrongtype.jpg' --not-found 'types/wrongtype.png' \
+    --found 'types/bigtype.jpg' --not-found 'types/bigtype.png' \
+    --found 'types/packed.jpg' --not-found 'types/packed.png' \
+    --found 'types/mutant.jpg' --not-found 'types/mutant.png' \
     httrack 'BASEURL/types/index.html'

tests/34_local-maxtime.test

@@ -0,0 +1,21 @@
+#!/bin/bash
+#
+# -E time limit (#481): server pages trickle for minutes; the engine must stop
+# on its own at -E plus grace, aborting the in-flight transfers.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+# cancelled crawls can orphan .delayed placeholders (#483): skip that audit
+start=$(date +%s)
+bash "$top_srcdir/tests/local-crawl.sh" \
+    --skip-delayed-audit \
+    --log-found 'More than 2 seconds passed' \
+    httrack 'BASEURL/trickle/index.html' -E2 -c4
+wall=$(($(date +%s) - start))
+# hard stop is due at -E2 + 5s grace; near TRICKLE_SECONDS means it never fired
+if [ "$wall" -ge 30 ]; then
+    echo "crawl took ${wall}s, -E hard stop did not engage" >&2
+    exit 1
+fi

tests/35_local-maxsize.test

@@ -0,0 +1,15 @@
+#!/bin/bash
+#
+# -M byte cap (#77): the crawl must stop with the "giving up" error and keep
+# the mirror well under the 8 x 640KB the fixture totals uncapped.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+# cap = -M + the 4 in-flight files the smooth stop lets finish + one of margin
+bash "$top_srcdir/tests/local-crawl.sh" \
+    --log-found 'More than 400000 bytes have been transferred.. giving up' \
+    --found bigfiles/p0.bin \
+    --max-mirror-bytes 3700000 \
+    httrack 'BASEURL/bigfiles/index.html' -M400000 -c4

tests/36_local-bigcrawl.test

@@ -0,0 +1,55 @@
+#!/bin/bash
+#
+# Diverse seeded /big/ crawl: 12 pattern families, decoy absence, update pass
+# must 304-revalidate. 360 = 1 index + 96 pages + 192 imgs + 5 shared + 60
+# family + 6 singles; the 4 planted errors write -o1 pages, not counted.
+
+set -euo pipefail
+
+: "${top_srcdir:=..}"
+
+bash "$top_srcdir/tests/local-crawl.sh" --rerun \
+    --errors 4 --files 360 \
+    --found 'big/p/95.html' \
+    --found 'big/a/d1/d2/d3/d4/d5/d6/d7/d8/deep.png' \
+    --found 'big/a/f2-2x.png' \
+    --found 'big/a/subs.vtt' \
+    --found 'big/a/font.woff2' \
+    --found 'big/a/js-data.bin' \
+    --found 'big/d/01.pdf' \
+    --found 'big/d/named.pdf' \
+    --found 'big/a/doc.pdf' \
+    --found "big/f9/caf$(printf '\xc3\xa9').html" \
+    --found 'big/f7/fa.html' \
+    --found 'big/a/ref.png' \
+    --found 'big/f6/sub/leaf.html' \
+    --found 'big/f1/dir/index.html' \
+    --found 'big/f10/empty.html' \
+    --found 'big/indexd41d.html' \
+    --found 'big/a/i0a.png' \
+    --not-found 'big/x/og' \
+    --not-found 'big/x/tw' \
+    --not-found 'big/x/jsonld.png' \
+    --not-found 'big/x/never-scanned.png' \
+    --not-found 'big/x/atom-only.html' \
+    --not-found 'big/x/sitemap-only.html' \
+    --not-found 'big/x/form-target.html' \
+    --not-found 'big/x/formact' \
+    --not-found 'big/x/ping' \
+    --not-found 'big/x/aj.jar' \
+    --not-found 'big/x/bj.jar' \
+    --not-found 'big/x/is1.png' \
+    --not-found 'big/x/concat.html' \
+    --file-matches 'big/p/2.html' 'srcset="\.\./a/f2-1x\.png 1x, \.\./a/f2-2x\.png 2x"' \
+    --file-matches 'big/a/blk2.css' 'url\(blk2-bg\.png\)' \
+    --file-matches 'big/p/5.html' "document\\.write\\('<a href=\"\\.\\./f5/dw\\.html\"" \
+    --file-not-matches 'big/p/1.html' 'href="/big/' \
+    --log-not-found 'bogus state|[Pp]anic|assert' \
+    --log-found '\(404\) at link [^ ]*/big/e/404\.html' \
+    --log-found '\(410\) at link [^ ]*/big/e/410\.html' \
+    --log-found '\(500\) at link [^ ]*/big/e/500\.html' \
+    --log-found 'decompressing.*big/e/gztrunc\.html' \
+    --log-found ', no files updated' \
+    --max-mirror-bytes 700000 \
+    --min-mirror-bytes 500000 \
+    httrack 'BASEURL/big/index.html' --retries=0 -c8 -%c100 -A100000000

tests/Makefile.am

@@ -54,6 +54,7 @@ TESTS = \
 	01_engine-savename.test \
 	01_engine-selftest-dispatch.test \
 	01_engine-simplify.test \
+	01_engine-sniff.test \
 	01_engine-status.test \
 	01_engine-stripquery.test \
 	01_engine-strsafe.test \
@@ -64,6 +65,7 @@ TESTS = \
 	01_zlib-cache.test \
 	01_zlib-cache-golden.test \
 	01_zlib-cache-writefail.test \
+	01_zlib-savename-cached.test \
 	02_manpage-regen.test \
 	02_update-cache.test \
 	10_crawl-simple.test \
@@ -94,6 +96,9 @@ TESTS = \
 	30_local-fragment-link.test \
 	31_local-javaclass.test \
 	32_local-cdispo.test \
-	33_local-delayed.test
+	33_local-delayed.test \
+	34_local-maxtime.test \
+	35_local-maxsize.test \
+	36_local-bigcrawl.test
 
 CLEANFILES = check-network_sh.cache

tests/local-crawl.sh

@@ -16,8 +16,10 @@
 #       --errors N --files N --found PATH ... --directory PATH ... \
 #       --log-found REGEX ... --log-not-found REGEX ... \
 #       --file-matches PATH REGEX ... --file-not-matches PATH REGEX ... \
+#       --max-mirror-bytes N \
 #       httrack BASEURL/some/path [httrack-args...]
 # --log-found/--log-not-found grep (ERE) the crawl's hts-log.txt.
+# --max/--min-mirror-bytes bound the mirrored content bytes (host root).
 # --file-matches/--file-not-matches grep (ERE) a mirrored file (PATH under the
 # host root), to assert rewritten link/content survived the crawl.
 # --cookie writes a Netscape cookies.txt (scoped to the discovered host:port,
@@ -92,6 +94,7 @@ tmpdir=$(mktemp -d "${tmptopdir}/httrack_local.XXXXXX") || die "could not create
 # --- parse leading control flags --------------------------------------------
 declare -a audit=()
 declare -a cookies=()
+skip_delayed_audit=""
 scheme=http
 pos=0
 args=("$@")
@@ -116,11 +119,14 @@ while test "$pos" -lt "$nargs"; do
         pos=$((pos + 1))
         cookies+=("${args[$pos]}")
         ;;
+    --skip-delayed-audit)
+        skip_delayed_audit=1
+        ;;
     --errors | --files)
         audit+=("${args[$pos]}" "${args[$((pos + 1))]}")
         pos=$((pos + 1))
         ;;
-    --found | --not-found | --directory | --log-found | --log-not-found)
+    --found | --not-found | --directory | --log-found | --log-not-found | --max-mirror-bytes | --min-mirror-bytes)
         audit+=("${args[$pos]}" "${args[$((pos + 1))]}")
         pos=$((pos + 1))
         ;;
@@ -246,12 +252,15 @@ done
 test -n "$hostroot" || die "could not find host root under $out"
 debug "host root: $hostroot"
 
-# A completed crawl must leave no .delayed temporaries (issue #107)
-info "checking for leftover .delayed files"
-leftovers=$(find "$out" -name '*.delayed' 2>/dev/null | head -5)
-if test -z "$leftovers"; then result "OK"; else
-    result "leftover: $leftovers"
-    exit 1
+# A completed crawl must leave no .delayed temporaries (issue #107).
+# --skip-delayed-audit: a cancelled crawl can orphan placeholders (issue #483)
+if test -z "$skip_delayed_audit"; then
+    info "checking for leftover .delayed files"
+    leftovers=$(find "$out" -name '*.delayed' 2>/dev/null | head -5)
+    if test -z "$leftovers"; then result "OK"; else
+        result "leftover: $leftovers"
+        exit 1
+    fi
 fi
 
 # --- audit -------------------------------------------------------------------
@@ -309,6 +318,24 @@ while test "$i" -lt "${#audit[@]}"; do
             exit 1
         else result "OK"; fi
         ;;
+    --max-mirror-bytes)
+        i=$((i + 1))
+        sz=$(find "$hostroot" -type f -exec cat {} + | wc -c | tr -d '[:space:]')
+        info "checking mirror size ${sz} <= ${audit[$i]} bytes"
+        if test "$sz" -le "${audit[$i]}"; then result "OK"; else
+            result "mirror too big"
+            exit 1
+        fi
+        ;;
+    --min-mirror-bytes)
+        i=$((i + 1))
+        sz=$(find "$hostroot" -type f -exec cat {} + | wc -c | tr -d '[:space:]')
+        info "checking mirror size ${sz} >= ${audit[$i]} bytes"
+        if test "$sz" -ge "${audit[$i]}"; then result "OK"; else
+            result "mirror too small"
+            exit 1
+        fi
+        ;;
     --file-matches)
         path="${audit[$((i + 1))]}"
         i=$((i + 2))

tests/local-server.py

@@ -14,6 +14,8 @@ stdlib only (http.server + ssl) -- no new build or runtime dependency.
 """
 
 import argparse
+import gzip
+import hashlib
 import os
 import time
 from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
@@ -41,6 +43,416 @@ PAGE = """<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 """
 
 
+# --- /big/ seeded pseudo-site (36_local-bigcrawl) ---------------------------
+# Deterministic ~360-file tree; bodies derive from sha256(BIG_SEED, name) so
+# every run serves identical content and the test pins exact counts.
+BIG_SEED = "bigcrawl-lite-1"
+BIG_PAGES = 96
+BIG_FANOUT = 4
+# Fixed validator: a matching If-Modified-Since gets 304, so the update pass
+# revalidates instead of re-downloading.
+BIG_LASTMOD = "Mon, 01 Jan 2024 00:00:00 GMT"
+
+BIG_CTYPES = {
+    "html": "text/html",
+    "css": "text/css",
+    "js": "application/x-javascript",
+    "png": "image/png",
+    "gif": "image/gif",
+    "jpg": "image/jpeg",
+    "webp": "image/webp",
+    "pdf": "application/pdf",
+    "woff2": "font/woff2",
+    "mp4": "video/mp4",
+    "webm": "video/webm",
+    "mp3": "audio/mpeg",
+    "vtt": "text/vtt",
+    "xml": "text/xml",
+    "svg": "image/svg+xml",
+    "jar": "application/java-archive",
+    "bin": "application/octet-stream",
+}
+
+# Honest magic bytes per claimed type so the #478 sniff never contests.
+BIG_MAGIC = {
+    "png": b"\x89PNG\r\n\x1a\n",
+    "gif": b"GIF89a",
+    "jpg": b"\xff\xd8\xff\xe0",
+    "webp": b"RIFF\x10\x27\x00\x00WEBPVP8 ",
+    "pdf": b"%PDF-1.4\n",
+    "woff2": b"wOF2",
+    "mp4": b"\x00\x00\x00\x18ftypmp42",
+    "webm": b"\x1a\x45\xdf\xa3",
+    "mp3": b"ID3\x04\x00\x00\x00\x00\x00\x00",
+    "jar": b"PK\x03\x04",
+}
+
+
+def big_blob(name, size):
+    out = b""
+    n = 0
+    while len(out) < size:
+        out += hashlib.sha256(f"{BIG_SEED}/{name}/{n}".encode()).digest()
+        n += 1
+    return out[:size]
+
+
+def big_asset(name):
+    ext = name.rsplit(".", 1)[-1]
+    size = 200 + int(hashlib.sha256(name.encode()).hexdigest(), 16) % 3800
+    raw = big_blob(name, size)
+    if ext in ("css", "js", "txt"):
+        return b"/* " + raw.hex().encode() + b" */"
+    return BIG_MAGIC.get(ext, b"") + raw
+
+
+def big_html(title, inner):
+    page = (
+        "<!DOCTYPE html><html><head><title>%s</title></head><body>\n%s\n</body></html>"
+        % (
+            title,
+            inner,
+        )
+    )
+    return page.encode()
+
+
+def _hexfill(name):
+    return big_blob(name, 160).hex()
+
+
+HOME = '<a href="/big/index.html">home</a>'
+
+BIG_TEXT_ASSETS = {
+    "site.css": (
+        "body { background: url(bg.png); } /* %s */" % _hexfill("site.css"),
+        "text/css",
+    ),
+    "print.css": ("p { margin: 0; } /* %s */" % _hexfill("print.css"), "text/css"),
+    "blk.css": (
+        '@import "blk2.css";\n'
+        '@font-face { font-family: big; src: local("Nope Sans"), '
+        'url(font.woff2) format("woff2"); }\n'
+        "/* %s */" % _hexfill("blk.css"),
+        "text/css",
+    ),
+    # Absolute url() must come back relative after the rewrite (test greps it);
+    # the \/ escapes collapse to an already-linked URL if taken literally.
+    "blk2.css": (
+        "body { background: url(/big/a/blk2-bg.png); }\n"
+        "i { background: url(/big\\/a\\/bg.png); }\n"
+        "/* %s */" % _hexfill("blk2.css"),
+        "text/css",
+    ),
+    # .open() grabs its first arg only (a method there is rejected, #218), so
+    # the window.open single-URL form is the token-detected shape.
+    "app.js": (
+        'var im = new Image(); im.src = "/big/a/js-img.png";\n'
+        'function pop() { window.open("/big/a/js-data.bin"); }\n'
+        "// %s\n" % _hexfill("app.js"),
+        "application/x-javascript",
+    ),
+    "heavy.js": (
+        'var h = new Image(); h.src = "/big/a/js1.png";\n'
+        'function nav() { location.href = "/big/p/1.html"; }\n'
+        'function pop() { window.open("/big/a/js2.bin"); }\n'
+        "// %s\n" % _hexfill("heavy.js"),
+        "application/x-javascript",
+    ),
+    # text/javascript is fetched but never scanned: the URL inside must stay
+    # out of the mirror.
+    "decoy.js": (
+        'var d = new Image(); d.src = "/big/x/never-scanned.png";\n',
+        "text/javascript",
+    ),
+    "subs.vtt": ("WEBVTT\n\n00:00.000 --> 00:01.000\nbig\n", "text/vtt"),
+    "logo.svg": (
+        '<svg xmlns="http://www.w3.org/2000/svg" width="4" height="4">'
+        '<image href="ref.png" width="4" height="4"/></svg>',
+        "image/svg+xml",
+    ),
+}
+
+
+def _fam_feeds(port):
+    return (
+        '<link rel="alternate" type="application/rss+xml" href="/big/f12/rss.xml">'
+        '<a href="/big/f12/atom.xml">atom</a>'
+        '<a href="/big/f12/sitemap.xml">sitemap</a>'
+    )
+
+
+def _fam_plain(port):
+    return (
+        '<a href="../f1/one.html">one</a>'
+        '<a href="./two.html">two</a>'
+        '<a href="../../big/f1/tri.html">tri</a>'
+        '<a href="/big/f1/abs.html">abs</a>'
+        '<a href="/big/f1/list.html">list</a>'
+        '<a href="/big/f1/list.html?page=2">p2</a>'
+        '<a href="/big/f1/list.html?page=3&amp;sort=asc">p3</a>'
+        '<a href="/big/f1/dir">dir</a>'
+        '<a href="">self</a><a href="#">frag</a>'
+        '<a href="mailto:big@example.com">mail</a>'
+        '<a href="tel:+15551234">tel</a>'
+        '<a href="data:text/plain;base64,aGk=">data</a>'
+    )
+
+
+def _fam_srcset(port):
+    return (
+        '<img src="/big/a/f2-base.png">'
+        '<img srcset="/big/a/f2-1x.png 1x, /big/a/f2-2x.png 2x"'
+        ' src="/big/a/f2-base.png">'
+        '<img data-srcset="/big/a/f2-1x.png 1x, /big/a/f2-2x.png 2x"'
+        ' src="/big/a/f2-base.png" loading="lazy">'
+        '<picture><source type="image/webp" srcset="/big/a/f2-alt.webp">'
+        '<img src="/big/a/f2-base.png"></picture>'
+    )
+
+
+def _fam_media(port):
+    return (
+        '<video src="/big/a/clip.mp4" poster="/big/a/poster.jpg">'
+        '<source src="/big/a/clip.webm" type="video/webm">'
+        '<track src="/big/a/subs.vtt" kind="subtitles" srclang="en">'
+        "</video>"
+        '<audio><source src="/big/a/tune.mp3" type="audio/mpeg"></audio>'
+    )
+
+
+def _fam_css(port):
+    # image-set with descriptors is a proven-safe decoy (engine-surface §6).
+    return (
+        '<link rel="stylesheet" href="/big/a/print.css" media="print">'
+        '<div style="background:url(/big/a/attr-bg.png)">styled</div>'
+        '<style>@import "/big/a/blk.css"; h1 { background: url(/big/a/blk-bg.gif); }'
+        ' h2 { background-image: image-set("/big/x/is1.png" 1x, "/big/x/is2.png" 2x); }'
+        "</style>"
+    )
+
+
+def _fam_js(port):
+    # The concatenated string is rejected by the scanner (no single literal).
+    return (
+        '<script src="/big/a/heavy.js"></script>'
+        '<script src="/big/a/decoy.js"></script>'
+        "<script>document.write('<a href=\"/big/f5/dw.html\">dw</a>');\n"
+        'var nope = "xx-" + "/big/x/concat.html";</script>'
+    )
+
+
+def _fam_meta(port):
+    # Extensionless decoy targets stay unfetchable even if the aggressive
+    # parser fires (no known extension, no scheme: rejected in every state).
+    return (
+        '<meta http-equiv="refresh" content="2;URL=/big/f6/refreshed.html">'
+        '<a href="/big/f6/based.html">based</a>'
+        '<meta property="og:image" content="/big/x/og">'
+        '<meta name="twitter:image" content="/big/x/tw">'
+        '<script type="application/ld+json">'
+        '{"@type": "Thing", "image": "/big/x/jsonld.png"}</script>'
+    )
+
+
+def _fam_legacy(port):
+    # Comma-valued applet archive is rejected whole by the engine (decoy).
+    return (
+        '<a href="/big/f7/frames.html">frames</a>'
+        '<img src="/big/a/map.gif" usemap="#m">'
+        '<map name="m">'
+        '<area shape="rect" coords="0,0,9,9" href="/big/f7/area.html"></map>'
+        '<embed src="/big/a/e.pdf" type="application/pdf" width="9" height="9">'
+        '<object data="/big/a/o.pdf" type="application/pdf"></object>'
+        '<applet archive="/big/x/aj.jar,/big/x/bj.jar" width="1" height="1"></applet>'
+    )
+
+
+def _fam_svg(port):
+    return (
+        '<svg width="9" height="9">'
+        '<image href="/big/a/svg-in.png" width="4" height="4"/>'
+        '<use xlink:href="#icon"/></svg>'
+        '<img src="/big/a/logo.svg">'
+    )
+
+
+def _fam_i18n(port):
+    return (
+        '<a href="/big/f9/caf%C3%A9.html">cafe</a>'
+        '<a href="/big/f9/latin1.html">latin1</a>'
+        '<a href="/big/f9/metaonly.html">meta</a>'
+        '<a href="/big/f9/bom.html">bom</a>'
+    )
+
+
+def _fam_http(port):
+    return (
+        '<a href="/big/r/hop1">chain</a>'
+        '<a href="/big/r/get42">get42</a>'
+        '<a href="/big/d/01">d01</a>'
+        '<a href="/big/d/02">d02</a>'
+        '<a href="/big/f10/empty.html">empty</a>'
+        '<a href="/big/d/dl">dl</a>'
+    )
+
+
+def _fam_forms(port):
+    # GET form action is rewritten but never fetched; formaction/ping are
+    # outside the attribute tables (decoys).
+    return (
+        '<form action="/big/x/form-target.html" method="get">'
+        '<input type="text" name="q">'
+        '<input type="image" src="/big/a/btn.png" alt="go"></form>'
+        '<a href="/big/f11/page.html">bare</a>'
+        '<a href="/big/f11/page.html?utm_source=news&amp;utm_medium=mail">utm</a>'
+        '<a href="/big/f11/sess.html?PHPSESSID=deadbeef123">sess</a>'
+        '<button formaction="/big/x/formact">go</button>'
+        '<a href="/big/f11/page.html" ping="/big/x/ping">ping</a>'
+    )
+
+
+BIG_FAMILIES = [
+    _fam_feeds,
+    _fam_plain,
+    _fam_srcset,
+    _fam_media,
+    _fam_css,
+    _fam_js,
+    _fam_meta,
+    _fam_legacy,
+    _fam_svg,
+    _fam_i18n,
+    _fam_http,
+    _fam_forms,
+]
+
+
+def big_link(m, style):
+    return ["%d.html" % m, "../p/%d.html" % m, "/big/p/%d.html" % m][style]
+
+
+def big_page(n, port):
+    style = n % 3
+    home = ["../index.html", "/big/index.html", "../index.html"][style]
+    parts = ['<a href="%s">home</a>' % home]
+    if n > 0:
+        parts.append('<a href="%s">up</a>' % big_link((n - 1) // BIG_FANOUT, style))
+    for c in range(n * BIG_FANOUT + 1, n * BIG_FANOUT + BIG_FANOUT + 1):
+        if c < BIG_PAGES:
+            parts.append('<a href="%s">p%d</a>' % (big_link(c, style), c))
+    parts.append('<link rel="stylesheet" href="/big/a/site.css">')
+    parts.append('<script src="/big/a/app.js"></script>')
+    exts = ["png", "gif", "jpg"]
+    ia = "/big/a/i%da.%s" % (n, exts[n % 3])
+    ib = "/big/a/i%db.%s" % (n, exts[(n + 1) % 3])
+    # Rotate the second-image construct across deterministic table attributes.
+    con = n % 4
+    if con == 0:
+        parts.append('<img src="%s"><img src="%s">' % (ia, ib))
+    elif con == 1:
+        parts.append(
+            '<img src="%s"><table background="%s"><tr><td>t</td></tr></table>'
+            % (ia, ib)
+        )
+    elif con == 2:
+        parts.append('<img src="%s"><img src="%s" data-src="%s">' % (ia, ia, ib))
+    else:
+        parts.append(
+            '<img src="%s" loading="lazy"><video poster="%s"></video>' % (ia, ib)
+        )
+    parts.append(BIG_FAMILIES[n % 12](port))
+    return big_html("p%d" % n, "\n".join(parts))
+
+
+def big_index(port):
+    return big_html(
+        "big index",
+        '<link rel="stylesheet" href="/big/a/site.css">'
+        '<script src="/big/a/app.js"></script>'
+        '<a href="p/0.html">root</a>'
+        '<img src="/big/a/d1/d2/d3/d4/d5/d6/d7/d8/deep.png">'
+        '<a href="/big/f1/long.html?x=%s">long</a>'
+        '<a href="/big/f1/gzok.html">gzok</a>'
+        '<a href="//127.0.0.1:%d/big/f1/protorel.html">protorel</a>'
+        '<a href="http://127.0.0.1:%d/big/f1/abshost.html">abshost</a>'
+        '<a href="/big/e/404.html">e404</a>'
+        '<a href="/big/e/410.html">e410</a>'
+        '<a href="/big/e/500.html">e500</a>'
+        '<a href="/big/e/gztrunc.html">gzt</a>'
+        '<a href="?">query</a>' % ("a" * 900, port, port),
+    )
+
+
+BIG_REDIRECTS = {
+    "/big/r/hop1": (301, "/big/r/hop2"),
+    "/big/r/hop2": (302, "/big/f10/land.html"),
+    "/big/r/get42": (301, "/big/a/doc.pdf"),
+    "/big/f1/dir": (301, "/big/f1/dir/"),
+}
+
+BIG_SIMPLE_PAGES = {
+    "/big/p/two.html": "dot-slash target",
+    "/big/f1/one.html": "one",
+    "/big/f1/tri.html": "tri",
+    "/big/f1/abs.html": "abs",
+    "/big/f1/dir/": "dir index",
+    "/big/f1/long.html": "long",
+    "/big/f1/gzok.html": "gzok",
+    "/big/f1/protorel.html": "protorel",
+    "/big/f1/abshost.html": "abshost",
+    "/big/f5/dw.html": "dw target",
+    "/big/f6/refreshed.html": "refreshed",
+    "/big/f6/sub/leaf.html": "leaf",
+    "/big/f7/fa.html": "frame a",
+    "/big/f7/fb.html": "frame b",
+    "/big/f7/fn.html": "noframes",
+    "/big/f7/area.html": "area",
+    "/big/f10/land.html": "landed",
+    "/big/f11/page.html": "the page",
+    "/big/f11/sess.html": "the sess page",
+}
+
+# Extensionless downloads: name resolution is wire-type driven (#478 contract).
+BIG_DOWNLOADS = {
+    "/big/d/01": ("pdf", None),
+    "/big/d/02": ("png", None),
+    "/big/d/dl": ("pdf", 'attachment; filename="named.pdf"'),
+}
+
+
+def _big_rss(port):
+    # purl.org marker makes the feed parse; item URLs are already-linked pages.
+    return (
+        '<?xml version="1.0"?>\n'
+        '<rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/">\n'
+        "<channel><title>big</title><link>http://127.0.0.1:%d/big/index.html</link>\n"
+        "<item><title>i1</title><link>http://127.0.0.1:%d/big/p/1.html</link>\n"
+        '<enclosure url="http://127.0.0.1:%d/big/p/2.html" type="text/html"/></item>\n'
+        "</channel></rss>\n" % (port, port, port)
+    ).encode()
+
+
+def _big_atom(port):
+    # No purl marker: emitted verbatim, its URL must never be fetched.
+    return (
+        '<?xml version="1.0"?>\n'
+        '<feed xmlns="http://www.w3.org/2005/Atom"><title>big</title>\n'
+        "<entry><title>e1</title>"
+        '<link href="http://127.0.0.1:%d/big/x/atom-only.html"/>'
+        "</entry></feed>\n" % port
+    ).encode()
+
+
+def _big_sitemap(port):
+    return (
+        '<?xml version="1.0"?>\n'
+        '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n'
+        "<url><loc>http://127.0.0.1:%d/big/x/sitemap-only.html</loc></url>\n"
+        "</urlset>\n" % port
+    ).encode()
+
+
 class Handler(SimpleHTTPRequestHandler):
     # Quieter logging; the launcher captures httrack's own log anyway.
     def log_message(self, fmt, *args):
@@ -150,6 +562,8 @@ class Handler(SimpleHTTPRequestHandler):
     # Fake-binary blobs for the image/pdf/typeless cases.
     FAKE_PNG = b"\x89PNG\r\n\x1a\n" + b"\x00" * 64
     FAKE_PDF = b"%PDF-1.4\n" + b"\x00" * 64
+    FAKE_JPEG = b"\xff\xd8\xff\xe0" + b"\x00" * 64
+    BIG_JPEG = b"\xff\xd8\xff\xe0" + bytes(range(256)) * 64  # > sniff window
 
     # path -> (body, content_type); None sends no header, "" sends an empty
     # Content-Type value (no usable type, must be treated like None).
@@ -161,6 +575,8 @@ class Handler(SimpleHTTPRequestHandler):
         "/types/notype.pdf": (FAKE_PDF, None),
         "/types/emptyct.png": (FAKE_PNG, ""),
         "/types/lie.png": (FAKE_PNG, "text/html"),
+        "/types/wrongtype.jpg": (FAKE_JPEG, "image/png"),
+        "/types/bigtype.jpg": (BIG_JPEG, "image/png"),
         "/types/report.pdf": (b"<html><body>real page</body></html>", "text/html"),
         "/types/page.htm": (b"<html><body>htm page</body></html>", "text/html"),
         "/types/script.js": (b"var x = 1;\n", "application/javascript"),
@@ -178,6 +594,10 @@ class Handler(SimpleHTTPRequestHandler):
             '\t<a href="notype.pdf">notypepdf</a>\n'
             '\t<img src="emptyct.png" />\n'
             '\t<img src="lie.png" />\n'
+            '\t<img src="wrongtype.jpg" />\n'
+            '\t<img src="bigtype.jpg" />\n'
+            '\t<img src="mutant.jpg" />\n'
+            '\t<img src="packed.jpg" />\n'
             '\t<a href="report.pdf">report</a>\n'
             '\t<a href="page.htm">htm</a>\n'
             '\t<script src="script.js"></script>\n'
@@ -192,6 +612,25 @@ class Handler(SimpleHTTPRequestHandler):
         body, ctype = self.TYPE_MATRIX[path]
         self.send_raw(body, ctype)
 
+    # content changes between crawls: run 1 sniffs JPEG, the update pass must
+    # keep the run-1 name (recorded verdict) even though the body is now PNG
+    MUTANT_SEEN = set()
+
+    def route_types_mutant(self):
+        path = urlsplit(self.path).path
+        body = self.FAKE_PNG if path in self.MUTANT_SEEN else self.FAKE_JPEG
+        if self.command != "HEAD":
+            self.MUTANT_SEEN.add(path)
+        self.send_raw(body, "image/png")
+
+    # gzip on the wire: the sniff must see the decoded body, not the stream
+    def route_types_packed(self):
+        self.send_raw(
+            gzip.compress(self.FAKE_JPEG),
+            "image/png",
+            extra_headers=[("Content-Encoding", "gzip")],
+        )
+
     # --- MIME-type exclusion abort (issue #58) -----------------------------
     # A -mime:application/pdf filter must abort the transfer once the header
     # arrives, not download the whole body and discard it.
@@ -436,6 +875,43 @@ class Handler(SimpleHTTPRequestHandler):
     def route_delayed_empty(self):
         self.send_raw(b"", "text/html")  # 200 + Content-Length: 0
 
+    # -E time-limit (#481): pages that trickle far longer than any -E budget,
+    # so only an engine-side abort can end the crawl.
+    TRICKLE_SECONDS = 60
+
+    def send_bin_index(self):
+        """Index page linking p0.bin..p7.bin (shared by trickle and bigfiles)."""
+        self.send_html(
+            "".join('\t<a href="p%d.bin">p%d</a>\n' % (i, i) for i in range(8))
+        )
+
+    def route_trickle_index(self):
+        self.send_bin_index()
+
+    def route_trickle_page(self):
+        self.send_response(200)
+        self.send_header("Content-Type", "application/octet-stream")
+        self.send_header("Content-Length", str(2 * self.TRICKLE_SECONDS))
+        self.end_headers()
+        if self.command == "HEAD":
+            return
+        try:
+            for _ in range(self.TRICKLE_SECONDS):
+                self.wfile.write(b"xy")
+                self.wfile.flush()
+                time.sleep(1.0)
+        except OSError:
+            pass
+
+    # -M byte cap (#77): large fast files so a crawl overruns -M immediately.
+    BIGFILE_BYTES = 640 * 1024
+
+    def route_bigfiles_index(self):
+        self.send_bin_index()
+
+    def route_bigfile(self):
+        self.send_raw(b"x" * self.BIGFILE_BYTES, "application/octet-stream")
+
     ROUTES = {
         "/cookies/entrance.php": route_entrance,
         "/cookies/second.php": route_second,
@@ -451,6 +927,10 @@ class Handler(SimpleHTTPRequestHandler):
         "/types/notype.pdf": route_types,
         "/types/emptyct.png": route_types,
         "/types/lie.png": route_types,
+        "/types/wrongtype.jpg": route_types,
+        "/types/bigtype.jpg": route_types,
+        "/types/mutant.jpg": route_types_mutant,
+        "/types/packed.jpg": route_types_packed,
         "/types/report.pdf": route_types,
         "/types/page.htm": route_types,
         "/types/script.js": route_types,
@@ -477,6 +957,24 @@ class Handler(SimpleHTTPRequestHandler):
         "/cdispo/fetch.php": route_cdispo,
         "/cdispo/evil.php": route_cdispo,
         "/delayed/index.html": route_delayed_index,
+        "/trickle/index.html": route_trickle_index,
+        "/trickle/p0.bin": route_trickle_page,
+        "/trickle/p1.bin": route_trickle_page,
+        "/trickle/p2.bin": route_trickle_page,
+        "/trickle/p3.bin": route_trickle_page,
+        "/trickle/p4.bin": route_trickle_page,
+        "/trickle/p5.bin": route_trickle_page,
+        "/trickle/p6.bin": route_trickle_page,
+        "/trickle/p7.bin": route_trickle_page,
+        "/bigfiles/index.html": route_bigfiles_index,
+        "/bigfiles/p0.bin": route_bigfile,
+        "/bigfiles/p1.bin": route_bigfile,
+        "/bigfiles/p2.bin": route_bigfile,
+        "/bigfiles/p3.bin": route_bigfile,
+        "/bigfiles/p4.bin": route_bigfile,
+        "/bigfiles/p5.bin": route_bigfile,
+        "/bigfiles/p6.bin": route_bigfile,
+        "/bigfiles/p7.bin": route_bigfile,
         "/delayed/noloc.php": route_delayed_noloc,
         "/delayed/selfloop.php": route_delayed_selfloop,
         "/delayed/redir.php": route_delayed_redir,
@@ -497,6 +995,146 @@ class Handler(SimpleHTTPRequestHandler):
         "/redir/target.html": route_redir_target,
     }
 
+    # --- /big/ seeded pseudo-site ------------------------------------------
+
+    def big_send(self, body, ctype, code=200, extra=()):
+        if code == 200 and self.headers.get("If-Modified-Since") == BIG_LASTMOD:
+            self.send_response(304)
+            self.send_header("Content-Length", "0")
+            self.end_headers()
+            return
+        self.send_response(code)
+        if code == 200:
+            self.send_header("Last-Modified", BIG_LASTMOD)
+        self.send_header("Content-Type", ctype)
+        self.send_header("Content-Length", str(len(body)))
+        for name, value in extra:
+            self.send_header(name, value)
+        self.end_headers()
+        if self.command != "HEAD":
+            self.wfile.write(body)
+
+    def big_error(self, code, reason):
+        body = big_html("error", "<p>%d</p>%s" % (code, HOME))
+        self.big_send(body, "text/html", code=code, extra=[("X-Reason", reason)])
+
+    def route_big(self):
+        split = urlsplit(self.path)
+        path = unquote(split.path)
+        port = self.server.server_address[1]
+        if path in BIG_REDIRECTS:
+            code, location = BIG_REDIRECTS[path]
+            self.send_response(code)
+            self.send_header("Location", location)
+            self.send_header("Content-Length", "0")
+            self.end_headers()
+        elif path == "/big/index.html":
+            self.big_send(big_index(port), "text/html")
+        elif path in BIG_SIMPLE_PAGES:
+            body = big_html(path, "<p>%s</p>%s" % (BIG_SIMPLE_PAGES[path], HOME))
+            if path == "/big/f1/gzok.html":
+                self.big_send(
+                    gzip.compress(body, mtime=0),
+                    "text/html",
+                    extra=[("Content-Encoding", "gzip")],
+                )
+            else:
+                self.big_send(body, "text/html")
+        elif path == "/big/f1/list.html":
+            # Pagination: distinct content per query string.
+            body = big_html("list", "<p>listing %s</p>%s" % (split.query or "1", HOME))
+            self.big_send(body, "text/html")
+        elif path == "/big/f6/based.html":
+            self.big_send(
+                big_html(
+                    "based",
+                    '<base href="http://127.0.0.1:%d/big/f6/sub/">'
+                    '<a href="leaf.html">leaf</a>' % port,
+                ),
+                "text/html",
+            )
+        elif path == "/big/f7/frames.html":
+            self.big_send(
+                b'<html><frameset cols="50%,50%"><frame src="fa.html">'
+                b'<frame src="fb.html"><noframes><body><a href="fn.html">fn</a>'
+                b"</body></noframes></frameset></html>",
+                "text/html",
+            )
+        elif path == "/big/f9/café.html":
+            self.big_send(big_html("cafe", "<p>cafe</p>%s" % HOME), "text/html")
+        elif path == "/big/f9/latin1.html":
+            self.big_send(
+                b"<html><body><p>caf\xe9 latin</p></body></html>",
+                "text/html; charset=ISO-8859-1",
+            )
+        elif path == "/big/f9/metaonly.html":
+            self.big_send(
+                '<html><head><meta charset="utf-8"></head>'
+                "<body><p>café meta</p></body></html>".encode(),
+                "text/html",
+            )
+        elif path == "/big/f9/bom.html":
+            self.big_send(
+                b"\xef\xbb\xbf" + big_html("bom", "<p>bom</p>%s" % HOME), "text/html"
+            )
+        elif path == "/big/f10/empty.html":
+            self.big_send(b"", "text/html")
+        elif path == "/big/f12/rss.xml":
+            self.big_send(_big_rss(port), "text/xml")
+        elif path == "/big/f12/atom.xml":
+            self.big_send(_big_atom(port), "application/xml")
+        elif path == "/big/f12/sitemap.xml":
+            self.big_send(_big_sitemap(port), "text/xml")
+        elif path.startswith("/big/p/"):
+            try:
+                n = int(path[len("/big/p/") : -len(".html")])
+            except ValueError:
+                n = -1
+            if 0 <= n < BIG_PAGES and path.endswith(".html"):
+                self.big_send(big_page(n, port), "text/html")
+            else:
+                self.big_error(404, "no such page")
+        elif path.startswith("/big/a/") or path.startswith("/big/x/"):
+            name = path[len("/big/a/") :]
+            if path.startswith("/big/a/") and name in BIG_TEXT_ASSETS:
+                text, ctype = BIG_TEXT_ASSETS[name]
+                self.big_send(text.encode(), ctype)
+            elif name.endswith(".html"):
+                # Decoy targets 200 so a parser leak becomes a mirror file.
+                self.big_send(big_html(name, "<p>%s</p>" % name), "text/html")
+            else:
+                ext = name.rsplit(".", 1)[-1]
+                ctype = BIG_CTYPES.get(ext, "application/octet-stream")
+                self.big_send(big_asset(name), ctype)
+        elif path in BIG_DOWNLOADS:
+            ext, cdispo = BIG_DOWNLOADS[path]
+            extra = [("Content-Disposition", cdispo)] if cdispo else []
+            self.big_send(
+                big_asset(path[len("/big/") :] + "." + ext),
+                BIG_CTYPES[ext],
+                extra=extra,
+            )
+        elif path == "/big/e/404.html":
+            self.big_error(404, "Not Found")
+        elif path == "/big/e/410.html":
+            self.big_error(410, "Gone")
+        elif path == "/big/e/500.html":
+            self.big_error(500, "Server Error")
+        elif path == "/big/e/gztrunc.html":
+            # Half a gzip stream, honest Content-Length: decode fails, and the
+            # missing Last-Modified keeps it the one uncacheable resource.
+            full = gzip.compress(big_html("gz", "x" * 3000), mtime=0)
+            body = full[: len(full) // 2]
+            self.send_response(200)
+            self.send_header("Content-Type", "text/html")
+            self.send_header("Content-Encoding", "gzip")
+            self.send_header("Content-Length", str(len(body)))
+            self.end_headers()
+            if self.command != "HEAD":
+                self.wfile.write(body)
+        else:
+            self.big_error(404, "no such big path")
+
     # --- dispatch ----------------------------------------------------------
 
     def reject_fragment(self):
@@ -512,6 +1150,9 @@ class Handler(SimpleHTTPRequestHandler):
     def dispatch(self):
         self._set_cookies = []
         path = urlsplit(self.path).path
+        if path.startswith("/big/"):
+            self.route_big()
+            return True
         # Match percent-encoded paths (accented #157 route) by their decoded form.
         handler = self.ROUTES.get(path) or self.ROUTES.get(unquote(path))
         if handler is not None: