Re: (info-stnd) search.c:regexp_search() finishes too early

[Sergey Poznyakoff]

Hi Gavin,

Thanks a lot for the report and the testcase.  I have fixed the bug
in the repository.  For your convenience, the patch is attached.
Please let me know if it works for you.

Regards,
Sergey

Index: info/search.c
===================================================================
--- info/search.c       (revision 5402)
+++ info/search.c       (working copy)
@@ -98,12 +98,14 @@
 {
   static char *previous_regexp = NULL;
   static char *previous_content = NULL;
+  static long previous_start, previous_end;
   static int was_insensitive = 0;
   static regex_t preg;
   static regmatch_t *matches;
-  static int match_alloc = 0;
-  static int match_count = 0;
+  static size_t match_alloc = 0;
+  static size_t match_count = 0;
   regoff_t pos;
+  regoff_t start = 0, end;

   if (previous_regexp == NULL
       || ((binding->flags & S_FoldCase) != was_insensitive)
@@ -153,9 +155,9 @@
       *q = '\0';

       result = regcomp (&preg, unescaped_regexp,
-                       REG_EXTENDED|
-                       REG_NEWLINE|
-                       (was_insensitive ? REG_ICASE : 0));
+                       REG_EXTENDED|
+                       REG_NEWLINE|
+                       (was_insensitive ? REG_ICASE : 0));
       free (unescaped_regexp);

       if (result != 0)
@@ -167,42 +169,43 @@
           return search_failure;
         }

-      previous_regexp = xstrdup(regexp);
+      previous_regexp = xstrdup (regexp);
     }

-  if (previous_content != binding->buffer)
+  if (binding->start < binding->end)
     {
+      start = binding->start;
+      end = binding->end;
+    }
+  else
+    {
+      start = binding->end;
+      end = binding->start;
+    }
+
+  if (previous_content != binding->buffer ||
+      previous_start != start ||
+      previous_end != end)
+    {
       /* new buffer to search in, let's scan it */
-      regoff_t start = 0, end;
-      size_t content_length;
       char saved_char;

-      if (binding->start < binding->end)
-       {
-         start = binding->start;
-         end = binding->end;
-       }
-      else
-       {
-         start = binding->end;
-         end = binding->start;
-       }
-      content_length = end - start + 1;
-
       previous_content = binding->buffer;
-      saved_char = previous_content[content_length-1];
-      previous_content[content_length-1] = '\0';
+      previous_start = start;
+      previous_end = end;
+      saved_char = previous_content[end];
+      previous_content[end] = '\0';

-      for (match_count = 0; start < content_length; )
+      for (match_count = 0; start < end; )
         {
           int result = 0;
-          if (match_count >= match_alloc)
+          if (match_count == match_alloc)
             {
               /* match list full. Initially allocate 256 entries, then double
                  every time we fill it */
-              match_alloc = (match_alloc > 0 ? match_alloc * 2 : 256);
-              matches = xrealloc (matches,
-                                 match_alloc * sizeof(regmatch_t));
+             if (match_alloc == 0)
+               match_alloc = 256;
+             matches = x2nrealloc (matches, &match_alloc, sizeof matches[0]);
             }

           result = regexec (&preg, &previous_content[start],
@@ -222,11 +225,9 @@
                 }
             }
           else
-            {
-              break;
-            }
+           break;
         }
-      previous_content[content_length-1] = saved_char;
+      previous_content[end] = saved_char;
     }

   pos = binding->start;