[5403] Fix search boundary checking.

[Sergey Poznyakoff]

Revision: 5403
          http://svn.sv.gnu.org/viewvc/?view=rev&root=texinfo&revision=5403
Author:   gray
Date:     2014-01-09 21:58:13 +0000 (Thu, 09 Jan 2014)
Log Message:
-----------
Fix search boundary checking.
Based on report from Gavin Smith <address@hidden>

* info/search.c (regexp_search): Save previous values of
start and end bounds (sorted) and rescan the buffer if these
differ from the actual values.
Fix boundary checking (using end bound instead of the buffer
length).
Use x2nrealloc to grow matches buffer.

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/info/search.c

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog     2014-01-06 23:50:13 UTC (rev 5402)
+++ trunk/ChangeLog     2014-01-09 21:58:13 UTC (rev 5403)
@@ -1,3 +1,15 @@
+2014-01-09  Sergey Poznyakoff  <address@hidden>
+
+       Fix search boundary checking.
+       Based on report from Gavin Smith <address@hidden>
+
+       * info/search.c (regexp_search): Save previous values of
+       start and end bounds (sorted) and rescan the buffer if these
+       differ from the actual values.
+       Fix boundary checking (using end bound instead of the buffer
+       length).
+       Use x2nrealloc to grow matches buffer.
+
 2014-01-06  Karl Berry  <address@hidden>
 
        * doc/texinfo.texi: 2014.

Modified: trunk/info/search.c
===================================================================
--- trunk/info/search.c 2014-01-06 23:50:13 UTC (rev 5402)
+++ trunk/info/search.c 2014-01-09 21:58:13 UTC (rev 5403)
@@ -1,8 +1,8 @@
 /* search.c -- searching large bodies of text.
    $Id$
 
-   Copyright 1993, 1997, 1998, 2002, 2004, 2007, 2008, 2009, 2011, 2013
-   Free Software Foundation, Inc.
+   Copyright 1993, 1997, 1998, 2002, 2004, 2007, 2008, 2009, 2011, 2013,
+   2014 Free Software Foundation, Inc.
 
    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
@@ -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;