Re: simple regex for highlighting _/* fails

Moin moin,

the PCRE author spotted the error quicky, and I verified the patch
works, for details see http://www.pcre.org/pcre.txt, middle of section
"How pcre_exec() returns captured substrings", patch attached:

----- Forwarded message from Philip Hazel <[email protected]> -----

> Date: Wed, 11 Apr 2007 09:56:24 +0100 (BST)
> From: Philip Hazel <[email protected]>
> Subject: Re: simple regex for highlighting _/* fails
> 
> On Tue, 10 Apr 2007, Rado S wrote:
> 
> > This is in regex.c (stripped to the relevant parts AFAICS):
> > ------ QUOTE BEGIN ------
> > void highlight_regexes( int row, struct regex_cache *regex, int color)
> > {
> >         char *ptr;
> >         int offsets[6];
> >         int offsets_size = ARRAY_SIZE(offsets);
> >         char buf[LEN];
> > 
> >         /* Get contents of line from the screen */
> >         screen_contents(row, 0, buf);
> >         ptr = buf;
> > 
> >         while (pcre_exec(regex->re, regex->extra, ptr, strlen(ptr), 0, 0, offsets, offsets_size) > 0) {
> 
> Instead of >0, that should be >= 0 because a value of 0 is returned if
> there is a match but not enough room in the offsets to store all the
> capturing parentheses. That's the bug. An offsets vector that is only 6
> long has room for just the main match plus one set of capturing parens.
> 
> -- 
> Philip Hazel, University of Cambridge Computing Service.

----- End forwarded message -----

-- 
© Rado S. -- You must provide YOUR effort for your goal!
EVERY effort counts: at least to show your attitude.
You're responsible for ALL you do: you get what you give.

--- torg/src/regex.c	Tue Mar 27 20:25:48 2007
+++ tgo/src/regex.c	Wed Apr 11 14:40:36 2007
@@ -162,7 +162,7 @@
 #endif /* USE_CURSES */
 	ptr = buf;
 
-	while (pcre_exec(regex->re, regex->extra, ptr, strlen(ptr), 0, 0, offsets, offsets_size) > 0) {
+	while (pcre_exec(regex->re, regex->extra, ptr, strlen(ptr), 0, 0, offsets, offsets_size) >= 0) {
 		/* we have a match */
 		if (color >= 0) /* color the matching text */
 			word_highlight_string(row, (ptr - buf) + offsets[0], offsets[1] - offsets[0], color);