FormPopulationFilter raises warning with old PCRE versions

[MugeSo@…]

FormPopulationFilter? raises a warning like:

PHP Warning: preg_match() [<a href='function.preg-match'>function.preg-match</a>]: Compilation failed: assertion expected after (?( at offset 34 in /path-to-agavi/filter/AgaviFormPopulationFilter.class.php on line 215

[david]

I need some reproduce code please

[MugeSo <mugeso@…>]

simply, the regex code used in FPF raises warning in my environment.

preg_match('/;\s*charset=(")?(?P<charset>.+?(?(-2)(?=(?<!\\\\)")|(?=[;\s])))(?(-2)")/i', '');

My environment(snippet): PHP 5.2.11 PCRE (Perl Compatible Regular Expressions) Support => enabled PCRE Library Version => 6.6 06-Feb-2006 iconv support => enabled iconv implementation => glibc iconv library version => 2.5 iconv.input_encoding => ISO-8859-1 => ISO-8859-1 iconv.internal_encoding => ISO-8859-1 => ISO-8859-1 iconv.output_encoding => ISO-8859-1 => ISO-8859-1 mbstring.detect_order => no value => no value mbstring.encoding_translation => Off => Off mbstring.func_overload => 0 => 0 mbstring.http_input => pass => pass mbstring.http_output => pass => pass mbstring.internal_encoding => no value => no value mbstring.language => neutral => neutral mbstring.strict_detection => Off => Off mbstring.substitute_character => no value => no value

[david]

That looks like a very old PCRE version... did you build your PHP against this old version intentionally? 5.2.11 should have 7.8 or 7.9, not 6.6. I'm sure that this old version is the problem. PHP 5.2.0, which is the minimum version required by Agavi, bundled PCRE 6.7.

[david]

Okay, so the (?(-2) for relative backreferences in conditional subpatterns was introduced in PCRE 7.2, which was bundled with PHP 5.2.4. Our current minimum version is 5.2.0, which won't support this unless it's compiled against a newer version of PCRE. I can look into an alternative approach for this that does not use conditional subpatterns, that would also solve the problem you are encountering.

[MugeSo <mugeso@…>]

Thanks, David

In fact, I didn't build php myself but use Utter Ramblings yum repository for php.  http://www.jasonlitka.com/yum-repository/ It was built against PCRE 6.6 :(

[Mugeso@…]

I find I need to updating PCRE to utter ramblings' one. It's my fault :$

But, It seems good that my fault brought good thing :D

[david]

Can you try this line as a replacement:

if(preg_match('/;\s*charset=(")?(?P<charset>.+?(?(1)(?=(?<!\\\\)")|($|(?=[;\s]))))(?(1)")/i', $meta->getAttribute('content'), $matches)) {

and tell me if it works for you?

P.S: this also fixes a bug where the regex only ever matched strings like text/html; charset="UTF-8" but never text/html; charset=UTF-8, i.e. without quotation marks. P.P.S: it never goes into this branch for me, by the way; it seems that my newer libxml detects a charset from an HTML document even in XML parsing mode by looking at a <meta http-equiv="Content-Type" header - what is your libxml version?

[david]

See related #1185

[Mugeso@…]

Replying to david:

Can you try this line as a replacement: {{{ if(preg_match('/;\s*charset=(")?(?P<charset>.+?(?(1)(?=(?<!\\\\)")|($|(?=[;\s]))))(?(1)")/i', $meta->getAttribute('content'), $matches)) { }}} and tell me if it works for you?

Cool! It works fine for me :)

P.P.S: it never goes into this branch for me, by the way; it seems that my newer libxml detects a charset from an HTML document even in XML parsing mode by looking at a <meta http-equiv="Content-Type" header - what is your libxml version?

the version is 2.6.26 in my environment(CentOS 5.4)

[david]

(In [4354]) Fix #1183: FormPopulationFilter? raises warning with old PCRE versions

[david]

(In [4355]) Fix #1185: HTML meta tag charset detection in AgaviFormPopulationFilter? never matches strings without quotation marks (also refs #1183)