Author: jim

Description:
this may very well be a bug in the fileinfo.so extension for PHP, but I wanted
to post it in here in the event that someone else comes across the problem when
using MediaWiki, and perhaps so that a flag can be added to workaround the bug.
When trying to do file uploads with MediaWiki, Apache was returning an Internal
Server Error, and I found this in my logs:

/usr/libexec/ld-elf.so.1: /usr/local/lib/php/20050922/fileinfo.so: Undefined
symbol "php_realpath"

To me, this looks like a fileinfo.so bug or a PHP bug, but I couldn't find
anything on PHP's bugzilla that looked relevant. Not wanting to go upsetting a
stable server by blindly upgrading PHP + extensions, I started digging through
the mediawiki code and traced the problem to the if block starting on line 487
in includes/MimeMagic.php. The if statement checks to see if finfo_open() and
finfo_file() are available, and uses them for Mime detection if they exist. This
was evaluating to true because my PHP installation *does* have these functions,
but there appears to be some kind of internal issue with the fileinfo library on
my server. I simply forced this if block to evaluate to false (by adding "&&
false" to the conditions) so that the block falls through to the next elseif,
which uses mime_content_type() instead. I suppose it might be reasonable to add
a flag $wgIgnoreFinfoFunctions to force MediaWiki to use mime_content_type()
instead in the presence of this issue. That is unless it's just a product of my
specific server set up (e.g. php version + fileinfo version + O/S = bug), in
which case I suppose it should still be noted, even if it doesn't warrant a new
configuration directive.

phpinfo:
PHP Version 5.1.6
System 4.11-STABLE FreeBSD 4.11-STABLE #0: Fri Jan i386
fileinfo support enabled
Server API CGI/FastCGI
PHP API 20041225
PHP Extension 20050922
Zend Extension 220051025

Version: 1.9.x
Severity: normal
OS: FreeBSD
Platform: PC