htsopt: fix copy_htsopt dropping unsigned-enum fields

copy_htsopt() copies each field only when it is not the "-1 means unset"
sentinel, written as `if (from->X > -1)`. The boolean/enum option
migrations turned nearlink, errpage and parseall into hts_boolean, which
GCC backs with unsigned int. `unsigned > -1` is always false, so those
three fields silently stopped being copied.

Cast to int at the guard to restore the signed sentinel test. Add a
hidden `httrack -#9` self-test that drives copy_htsopt over distinct
boolean values plus an int positive control (tests/01_engine-copyopt.test);
it fails on the unfixed guard.

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

src/htscore.c

@@ -3702,7 +3702,9 @@ HTSEXT_API int copy_htsopt(const httrackp * from, httrackp * to) {
   if (from->maxsoc > 0)
     to->maxsoc = from->maxsoc;
 
-  if (from->nearlink > -1)
+  /* hts_boolean/enum fields are unsigned (GCC), so a bare `> -1` unset-guard
+     is always false; cast to int to keep the -1 "unset" sentinel test. */
+  if ((int) from->nearlink > -1)
     to->nearlink = from->nearlink;
 
   if (from->timeout > -1)
@@ -3729,10 +3731,10 @@ HTSEXT_API int copy_htsopt(const httrackp * from, httrackp * to) {
   if (from->hostcontrol > -1)
     to->hostcontrol = from->hostcontrol;
 
-  if (from->errpage > -1)
+  if ((int) from->errpage > -1)
     to->errpage = from->errpage;
 
-  if (from->parseall > -1)
+  if ((int) from->parseall > -1)
     to->parseall = from->parseall;
 
   // test all: bit 8 de travel

src/htscoremain.c

@@ -3096,6 +3096,41 @@ static int hts_main_internal(int argc, char **argv, httrackp * opt) {
                 htsmain_free();
                 return 0;
                 break;
+              case '9': { // copy_htsopt selftest: httrack -#9
+                httrackp *from = hts_create_opt();
+                httrackp *to = hts_create_opt();
+                int err = 0;
+
+                /* from-values differ from both the to-values and the
+                   hts_create_opt() defaults (nearlink FALSE, errpage/parseall
+                   TRUE), so a copy that no-ops or just resets to defaults is
+                   caught too, not only the unsigned-guard bug. */
+                from->retry = 7; /* int field: positive control */
+                to->retry = 0;
+                from->nearlink = HTS_TRUE;
+                to->nearlink = HTS_FALSE;
+                from->errpage = HTS_FALSE;
+                to->errpage = HTS_TRUE;
+                from->parseall = HTS_FALSE;
+                to->parseall = HTS_TRUE;
+
+                copy_htsopt(from, to);
+
+                if (to->retry != 7)
+                  err = 1;
+                if (to->nearlink != HTS_TRUE)
+                  err = 1;
+                if (to->errpage != HTS_FALSE)
+                  err = 1;
+                if (to->parseall != HTS_FALSE)
+                  err = 1;
+
+                hts_free_opt(from);
+                hts_free_opt(to);
+                printf("copy-htsopt: %s\n", err ? "FAIL" : "OK");
+                htsmain_free();
+                return err;
+              } break;
               case '!':
                 HTS_PANIC_PRINTF
                   ("Option #! is disabled for security reasons");

tests/01_engine-copyopt.test

@@ -0,0 +1,17 @@
+#!/bin/bash
+#
+# Regression guard for the unsigned-enum sentinel trap: copy_htsopt's
+# `if (from->X > -1)` guard is always false for unsigned hts_boolean fields, so
+# they silently stop being copied. Driven by the in-process 'httrack -#9' test.
+# Keep POSIX-portable (harness runs it via $(BASH), a plain /bin/sh on macOS).
+
+set -eu
+
+# A trailing token is required; a bare '-#9' falls through to the usage screen.
+out=$(httrack -#9 run)
+
+# Exact-match the success line so a fall-through to usage can't pass the test.
+test "$out" = "copy-htsopt: OK" || {
+    echo "expected 'copy-htsopt: OK', got: $out" >&2
+    exit 1
+}

tests/Makefile.am

@@ -24,6 +24,7 @@ TESTS = \
 	01_engine-cache-golden.test \
 	01_engine-charset.test \
 	01_engine-cmdline.test \
+	01_engine-copyopt.test \
 	01_engine-doitlog.test \
 	01_engine-entities.test \
 	01_engine-filter.test \