Description: pcre_exec does not fill offsets for certain regexps
Origin: upstream, http://vcs.pcre.org/pcre/code/trunk/pcre_exec.c?r1=1502&r2=1510
Bug: https://bugs.exim.org/show_bug.cgi?id=1537
Bug-Debian: https://bugs.debian.org/794589
Forwarded: not-needed
Last-Update: 2015-09-10
Applied-Upstream: 8.37

--- a/pcre_exec.c
+++ b/pcre_exec.c
@@ -1467,7 +1467,18 @@ for (;;)
       md->offset_vector[offset] =
         md->offset_vector[md->offset_end - number];
       md->offset_vector[offset+1] = (int)(eptr - md->start_subject);
-      if (offset_top <= offset) offset_top = offset + 2;
+
+      /* If this group is at or above the current highwater mark, ensure that
+      any groups between the current high water mark and this group are marked
+      unset and then update the high water mark. */
+
+      if (offset >= offset_top)
+        {
+        register int *iptr = md->offset_vector + offset_top;
+        register int *iend = md->offset_vector + offset;
+        while (iptr < iend) *iptr++ = -1;
+        offset_top = offset + 2;
+        }
       }
     ecode += 1 + IMM2_SIZE;
     break;
