Re: [BUG] Regexp compiler, problem with character classes

[Chong Yidong <cyd@stupidchicken.com>]

bojohan+news@dd.chalmers.se (Johan Bockgård) writes:

>>> The easiest way to fix that bug is to make each element of the
>>> compiled regexp cache specify the syntax table that it corresponds
>>> to, and make modify-syntax-entry clear the cache. That way, no
>>> change in regex.c is needed.
>> Does this patch look OK? [...]
>
> The "make each element of the compiled regexp cache specify the syntax
> table that it corresponds to" part is still needed.
>
> Here's an example:
>
>     $ emacs -Q
>
>     Evaluate in *scratch*:
>
>       (list
>        (string-match "x[[:space:]]" "x\n")
>        (with-temp-buffer
>          (string-match "x[[:space:]]" "x\n")))
>
>     => (nil nil)
>
> Expected: (nil 0)

You're right; the following additional patch should fix that.

*** emacs/src/search.c.~1.213.~	2006-09-18 08:39:59.000000000 -0400
--- emacs/src/search.c	2006-09-18 08:51:50.000000000 -0400
***************
*** 41,47 ****
  struct regexp_cache
  {
    struct regexp_cache *next;
!   Lisp_Object regexp, whitespace_regexp;
    struct re_pattern_buffer buf;
    char fastmap[0400];
    /* Nonzero means regexp was compiled to do full POSIX backtracking.  */
--- 41,47 ----
  struct regexp_cache
  {
    struct regexp_cache *next;
!   Lisp_Object regexp, whitespace_regexp, syntax_table;
    struct re_pattern_buffer buf;
    char fastmap[0400];
    /* Nonzero means regexp was compiled to do full POSIX backtracking.  */
***************
*** 167,172 ****
--- 167,173 ----
    cp->posix = posix;
    cp->buf.multibyte = multibyte;
    cp->whitespace_regexp = Vsearch_spaces_regexp;
+   cp->syntax_table = current_buffer->syntax_table;
    /* Doing BLOCK_INPUT here has the effect that
       the debugger won't run if an error occurs.
       Why is BLOCK_INPUT needed here?  */
***************
*** 256,261 ****
--- 257,263 ----
  	  && EQ (cp->buf.translate, (! NILP (translate) ? translate : make_number (0)))
  	  && cp->posix == posix
  	  && cp->buf.multibyte == multibyte
+ 	  && EQ (cp->syntax_table, current_buffer->syntax_table)
  	  && !NILP (Fequal (cp->whitespace_regexp, Vsearch_spaces_regexp)))
  	break;
  
***************
*** 3114,3121 ****
--- 3116,3125 ----
        searchbufs[i].buf.fastmap = searchbufs[i].fastmap;
        searchbufs[i].regexp = Qnil;
        searchbufs[i].whitespace_regexp = Qnil;
+       searchbufs[i].syntax_table = Qnil;
        staticpro (&searchbufs[i].regexp);
        staticpro (&searchbufs[i].whitespace_regexp);
+       staticpro (&searchbufs[i].syntax_table);
        searchbufs[i].next = (i == REGEXP_CACHE_SIZE-1 ? 0 : &searchbufs[i+1]);
      }
    searchbuf_head = &searchbufs[0];