From: stuge-phpbugs at cdy dot org
Operating system: Linux
PHP version: 4.3.1
PHP Bug Type: *Regular Expressions
Bug description: [ep]reg_replace "z?$" with "a" in "xyz" yields "xyaa" instead of
"xya"
Verified with 4.3.0 and 4.3.2rc2 but haven't tried 4.3.2. NEWS for 4.3.2 do
not mention any *reg_replace changes. Reproducible with eregi_replace().
<?php
$f="xyz";
$g=ereg_replace("z?$","a",$f);
$h=preg_replace("/z?$/","a",$f);
print $f; /* xyz */
print " ".$g; /* xyaa, I want xya */
print " ".$h; /* xyaa, I want xya */
?>
At least in CVS php4/ext/standard/reg.c I believe the problem is that
regexec() on line 306 will be called a second time after the first
iteration has already matched to the end of the string.
Matching from the end of the string should only be allowed on the very
first iteration.
If this analysis is correct, the following patch might work, but I haven't
tried it.
--- reg.c.org 2003-06-02 05:23:51.000000000 +0200
+++ reg.c 2003-06-02 05:26:06.000000000 +0200
@@ -302,7 +302,7 @@
err = pos = 0;
buf[0] = '\0';
- while (!err) {
+ do {
err = regexec(&re, &string[pos], re.re_nsub+1, subs, (pos
? REG_NOTBOL : 0));
if (err && err != REG_NOMATCH) {
@@ -396,7 +396,7 @@
/* stick that last bit of string on our output */
strcat(buf, &string[pos]);
}
- }
+ } while(!err && string[pos]);
/* don't want to leak memory .. */
efree(subs);
--
Edit bug report at http://bugs.php.net/?id=23946&edit=1
--
Try a CVS snapshot: http://bugs.php.net/fix.php?id=23946&r=trysnapshot
Fixed in CVS: http://bugs.php.net/fix.php?id=23946&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=23946&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=23946&r=needtrace
Try newer version: http://bugs.php.net/fix.php?id=23946&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=23946&r=support
Expected behavior: http://bugs.php.net/fix.php?id=23946&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=23946&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=23946&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=23946&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=23946&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=23946&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=23946&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=23946&r=gnused
