* search.c (clear_regexp_cache): New function.

	* syntax.c (Fmodify_syntax_entry): Clear regexp cache.

src/ChangeLog

+2006-09-17  Chong Yidong  <cyd@stupidchicken.com>
+
+	* search.c (clear_regexp_cache): New function.
+
+	* syntax.c (Fmodify_syntax_entry): Clear regexp cache.
+
 2006-09-16  Jan Dj,Ad(Brv  <jan.h.d@swipnet.se>
 	* gtkutil.c (xg_get_file_with_chooser): Check

src/search.c

@@ -207,6 +207,19 @@ shrink_regexp_cache ()
     }
 }
 
+/* Clear the regexp cache.
+   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.  */
+void
+clear_regexp_cache ()
+{
+  int i;
+
+  for (i = 0; i < REGEXP_CACHE_SIZE; ++i)
+    searchbufs[i].regexp = Qnil;
+}
+
 /* Compile a regexp if necessary, but first check to see if there's one in
    the cache.
    PATTERN is the pattern to compile.

src/syntax.c

@@ -1039,6 +1039,11 @@ usage: (modify-syntax-entry CHAR NEWENTRY &optional SYNTAX-TABLE) */)
     check_syntax_table (syntax_table);
 
   SET_RAW_SYNTAX_ENTRY (syntax_table, XINT (c), Fstring_to_syntax (newentry));
+
+  /* We clear the regexp cache, since character classes can now have
+     different values from those in the compiled regexps.*/
+  clear_regexp_cache ();
+
   return Qnil;
 }