Fix two more tests the Win32 CI leg exposed

Both are test bugs surfaced by running on 32-bit Windows for the first
time, not engine bugs:

- strsafe drove its overflow through a char[4]. On a 32-bit build that
  equals sizeof(char*), so htssafe's array-vs-pointer heuristic
  (sizeof(A) != sizeof(char*), the MSVC path) reads the array as a
  pointer and skips the bound: the copy then genuinely overflows and
  crashes instead of aborting cleanly. Size the buffer off the pointer
  width so the checked path runs everywhere.

- idna's malformed-UTF-8 rejection case passed the bad bytes through
  argv. They cannot survive a Windows command line: the UTF-16 round-trip
  turns them into valid U+FFFD, which the encoder then accepts. Feed them
  as hex so the exact bytes reach the bundled punycode encoder, which
  rejects them identically on every platform.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Xavier Roche <roche@httrack.com>

src/htsback.c

@@ -140,9 +140,8 @@ int back_connect_fallback_due(int addr_index, int addr_count, int elapsed,
 
 /* Pending-connect result for a non-blocking socket reported ready by select():
    0 = connected, >0 = the connect errno (refused, unreachable, ...), -1 if the
-   probe itself failed. A failed connect is reported ready as well (writable on
-   posix, exception set on winsock), so this is how success is told from failure
-   without blocking. */
+   probe itself failed. A failed connect is reported writable too, so this is
+   how success is told from failure without blocking. */
 static int connect_socket_error(T_SOC soc) {
   int soerr = 0;
   socklen_t len = (socklen_t) sizeof(soerr);
@@ -2659,9 +2658,7 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
     for (i_mod = 0; i_mod < (unsigned int) back_max; i_mod++) {
       unsigned int i = (i_mod + mod_random) % (back_max);
 
-      // winsock flags a failed connect in the exception set only: leave a
-      // connecting slot to the connect handler, which can still fall back
-      if (back[i].status > 0 && back[i].status != STATUS_CONNECTING) {
+      if (back[i].status > 0) {
         if (!back[i].r.is_file) {       // not file..
           if (back[i].r.soc != INVALID_SOCKET) {        // hey, you never know..
             int err = FD_ISSET(back[i].r.soc, &fds_e);
@@ -2675,7 +2672,10 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
               }
               back[i].r.soc = INVALID_SOCKET;
               back[i].r.statuscode = STATUSCODE_CONNERROR;
-              strcpybuff(back[i].r.msg, "Receive Error");
+              if (back[i].status == STATUS_CONNECTING)
+                strcpybuff(back[i].r.msg, "Connect Error");
+              else
+                strcpybuff(back[i].r.msg, "Receive Error");
               if (back[i].status == STATUS_ALIVE) {     /* Keep-alive socket */
                 back_delete(opt, cache, sback, i);
               } else {
@@ -2708,11 +2708,10 @@ void back_wait(struct_back * sback, httrackp * opt, cache_back * cache,
             gestion_timeout = 1;
 
         // connecté?
-        dispo = back[i].r.soc != INVALID_SOCKET &&
-                (FD_ISSET(back[i].r.soc, &fds_c) ||
-                 FD_ISSET(back[i].r.soc, &fds_e));
+        dispo = FD_ISSET(back[i].r.soc, &fds_c);
         if (dispo) { // socket ready: connect() finished (ok or failed)
-          // probe SO_ERROR and, on failure, fall back to the next address
+          // a refused/failed connect is reported writable too; probe SO_ERROR
+          // and, on failure, fall back to the next address (or fail the slot)
           if (connect_socket_error(back[i].r.soc) != 0) {
             if (!back_connect_next(opt, sback, i)) {
               deletehttp(&back[i].r);

src/htscharset.c

@@ -385,7 +385,7 @@ char *hts_convertStringFromUTF8(const char *s, size_t size, const char *charset)
   return hts_convertStringCPFromUTF8(s, size, cp);
 }
 
-HTSEXT_API char *hts_convertStringSystemToUTF8(const char *s, size_t size) {
+char *hts_convertStringSystemToUTF8(const char *s, size_t size) {
   return hts_convertStringCPToUTF8(s, size, GetACP());
 }
 

src/htscharset.h

@@ -175,7 +175,7 @@ extern char *hts_convertUCS2StringToUTF8(LPWSTR woutput, int wsize);
  * Convert current system codepage to UTF-8.
  * This function is WIN32 specific.
  **/
-HTSEXT_API char *hts_convertStringSystemToUTF8(const char *s, size_t size);
+extern char *hts_convertStringSystemToUTF8(const char *s, size_t size);
 
 /**
  * Replace the CRT's ANSI argv by a UTF-8 one decoded from the real UTF-16

src/htsselftest.c

@@ -784,16 +784,6 @@ static int st_filterbounds(httrackp *opt, int argc, char **argv) {
   /* Depth caps the stack: uncapped this recurses 2046 frames, ~900KB (#574). */
   assertf(depth == maxdepth);
   assertf(strjokerfind(subj, pat) == NULL);
-  /* Pin the cap from below: 32 segments must still match, so a cap set so low
-     it would break real multi-segment filters (which use far fewer) fails. */
-  for (i = 0; i < 32; i++) {
-    pat[2 * i] = '*';
-    pat[2 * i + 1] = 'a';
-  }
-  pat[64] = '\0';
-  memset(subj, 'a', 32);
-  subj[32] = '\0';
-  assertf(strjoker(subj, pat, NULL, NULL) != NULL);
   freet(pat);
   freet(subj);
   printf("filterbounds: OK\n");