* search.c (compile_pattern): If a cache entry has a nil regexp, fill in that

entry instead of clobbering a previously cached string regexp.

2 files changed, 17 insertions, 1 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f3b41fcf188..5251578b710 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2000-02-03  Ken Raeburn  <raeburn@raeburn.org>
+
+        * search.c (compile_pattern): If a cache entry has a nil regexp,
+        fill in that entry instead of clobbering a previously cached
+        string regexp.
+
 2000-02-02  Ken Raeburn  <raeburn@raeburn.org>
 
         * puresize.h (BASE_PURESIZE): Increase to 610000.
diff --git a/src/search.c b/src/search.c
index 5bcbaa615b3..3111548af58 100644
--- a/src/search.c
+++ b/src/search.c
@@ -219,6 +219,13 @@ compile_pattern (pattern, regp, translate, posix, multibyte)
   for (cpp = &searchbuf_head; ; cpp = &cp->next)
     {
       cp = *cpp;
+      /* Entries are initialized to nil, and may be set to nil by
+         compile_pattern_1 if the pattern isn't valid.  Don't apply
+         XSTRING in those cases.  However, compile_pattern_1 is only
+         applied to the cache entry we pick here to reuse.  So nil
+         should never appear before a non-nil entry.  */
+      if (cp->regexp == Qnil)
+        goto compile_it;
       if (XSTRING (cp->regexp)->size == XSTRING (pattern)->size
           && !NILP (Fstring_equal (cp->regexp, pattern))
           && EQ (cp->buf.translate, (! NILP (translate) ? translate : make_number (0)))
@@ -226,9 +233,12 @@ compile_pattern (pattern, regp, translate, posix, multibyte)
           && cp->buf.multibyte == multibyte)
         break;
 
-      /* If we're at the end of the cache, compile into the last cell.  */
+      /* If we're at the end of the cache, compile into the nil cell
+         we found, or the last (least recently used) cell with a
+         string value.  */
       if (cp->next == 0)
         {
+        compile_it:
           compile_pattern_1 (cp, pattern, translate, regp, posix, multibyte);
           break;
         }