#46763 [Com]: mb_stristr() wrong output when needle does not exist

[typoon at gmail dot com]

 ID:               46763
 Comment by:       typoon at gmail dot com
 Reported By:      a...@php.net
 Status:           Open
 Bug Type:         mbstring related
 Operating System: *
 PHP Version:      5.3CVS-2008-12-05 (snap)
 New Comment:

In the file mbstring.c on function mb_stristr the variable 'n' used to
determine the position of needle on haystack was changed from signed int
to unsignedint. When the php_mb_stripos function does not find needle in
haystack it returns -1 to n. As n is unsigned, that value will be huge,
causing the problem.

Here is a simple patch that might fix the issue.

Index: ext/mbstring/mbstring.c
===================================================================
RCS file: /repository/php-src/ext/mbstring/mbstring.c,v
retrieving revision 1.224.2.22.2.25.2.41
diff -u -u -w -p -r1.224.2.22.2.25.2.41 mbstring.c
--- ext/mbstring/mbstring.c     27 Dec 2008 13:32:24
-0000   1.224.2.22.2.25.2.41
+++ ext/mbstring/mbstring.c     30 Dec 2008 00:58:31 -0000
@@ -2555,7 +2555,8 @@ PHP_FUNCTION(mb_strrchr)
 PHP_FUNCTION(mb_stristr)
 {
        zend_bool part = 0;
-       unsigned int n, from_encoding_len, len, mblen;
+       unsigned from_encoding_len, len, mblen;
+       int n;
        mbfl_string haystack, needle, result, *ret = NULL;
        const char *from_encoding =
mbfl_no2preferred_mime_name(MBSTRG(current_internal_encoding));
        mbfl_string_init(&haystack);


Previous Comments:
------------------------------------------------------------------------

[2008-12-05 14:00:47] a...@php.net

Description:
------------
Take a look at the mb_stristr_basic.phpt test just checked into
5.3/6.0.  The test passes fine on 5.2 and fails on 5.3 and 6.0.

Reproduce code:
---------------
ext/mbstring/tests/mb_stristr_basic.phpt

Expected result:
----------------
*** Testing mb_stristr() : basic functionality ***

-- ASCII string: needle exists --
string(10) "6263646566"
string(10) "6263646566"
string(2) "61"

-- ASCII string: needle doesn't exist --
bool(false)

-- Multibyte string: needle exists --
string(52) "cebccebdcebecebfcf80cf81cf83cf84cf85cf86cf87cf88cf89"
string(52) "cebccebdcebecebfcf80cf81cf83cf84cf85cf86cf87cf88cf89"
string(44) "ceb1ceb2ceb3ceb4ceb5ceb6ceb7ceb8ceb9cebacebb"

-- Multibyte string: needle doesn't exist --
bool(false)
===DONE===


Actual result:
--------------
*** Testing mb_stristr() : basic functionality ***

-- ASCII string: needle exists --
string(10) "6263646566"
string(10) "6263646566"
string(2) "61"

-- ASCII string: needle doesn't exist --
string(6) "abcdef"

-- Multibyte string: needle exists --
string(52) "cebccebdcebecebfcf80cf81cf83cf84cf85cf86cf87cf88cf89"
string(52) "cebccebdcebecebfcf80cf81cf83cf84cf85cf86cf87cf88cf89"
string(44) "ceb1ceb2ceb3ceb4ceb5ceb6ceb7ceb8ceb9cebacebb"

-- Multibyte string: needle doesn't exist --
string(48) "αβγδεζηθικλμνξοπρστυφχψω"
===DONE===



------------------------------------------------------------------------


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Edit this bug report at http://bugs.php.net/?id=46763&edit=1