(compile_pattern): Only check `cp->syntax_table' if needed.

(compile_pattern_1): Remember `used_syntax' in `cp->syntax_table'.
(clear_regexp_cache): Only flush those regexps which depend on
a syntax-table.

2 files changed, 21 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index b13d015c01a..f64020ca34d 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,17 @@
+2006-10-03  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * lisp.h (clear_regexp_cache): Declare.
+
+        * search.c (compile_pattern): Only check `cp->syntax_table' if needed.
+        (compile_pattern_1): Remember `used_syntax' in `cp->syntax_table'.
+        (clear_regexp_cache): Only flush those regexps which depend on
+        a syntax-table.
+
+        * regex.c (regex_compile): Set the new `used_syntax' bit.
+
+        * regex.h: Remove file local variables.
+        (struct re_pattern_buffer): New field `used_syntax'.
+
 2006-10-03  Kim F. Storm  <storm@cua.dk>
 
         * process.c (list_processes_1): Run sentinels before removing dead
diff --git a/src/search.c b/src/search.c
index 5f9f321067a..7c3151b76b8 100644
--- a/src/search.c
+++ b/src/search.c
@@ -216,7 +216,8 @@ shrink_regexp_cache ()
     }
 }
 
-/* Clear the regexp cache.
+/* Clear the regexp cache w.r.t. a particular syntax table,
+   because it was changed.
    There is no danger of memory leak here because re_compile_pattern
    automagically manages the memory in each re_pattern_buffer struct,
    based on its `allocated' and `buffer' values.  */
@@ -226,7 +227,11 @@ clear_regexp_cache ()
   int i;
 
   for (i = 0; i < REGEXP_CACHE_SIZE; ++i)
-    searchbufs[i].regexp = Qnil;
+    /* It's tempting to compare with the syntax-table we've actually changd,
+       but it's not sufficient because char-table inheritance mewans that
+       modifying one syntax-table can change others at the same time.  */
+    if (!EQ (searchbufs[i].syntax_table, Qt))
+      searchbufs[i].regexp = Qnil;
 }
 
 /* Compile a regexp if necessary, but first check to see if there's one in