media: Capture stderr when running 'convert --version'

At Wikimedia, $wgImageMagickConvertCommand points to a shell wrapper
that invokes ImageMagick convert with:

  firejail --profile=/etc/firejail/mediawiki-converters.profile

firejail emits to stderr an information message:

  Reading profile /etc/firejail/mediawiki-converters.profile

That ends up in HHVM stderr and is populated up to logstash as an error.

MediaWiki does check imagemagick version by running `convert -version`,
switch from wfShellExec() to wfShellExecWithStderr().

Bug: T158649
Change-Id: I78d1ef59533c605f59b42e10556bb595d6c2cc15

diff --git a/includes/media/TransformationalImageHandler.php b/includes/media/TransformationalImageHandler.php
index 1ab0f36..2a74e0d 100644 (file)
--- a/includes/media/TransformationalImageHandler.php
+++ b/includes/media/TransformationalImageHandler.php
@@ -521,7 +521,7 @@ abstract class TransformationalImageHandler extends ImageHandler {
                                $cmd = wfEscapeShellArg( $wgImageMagickConvertCommand ) . ' -version';
                                wfDebug( $method . ": Running convert -version\n" );
                                $retval = '';
-                               $return = wfShellExec( $cmd, $retval );
+                               $return = wfShellExecWithStderr( $cmd, $retval );
                                $x = preg_match(
                                        '/Version: ImageMagick ([0-9]*\.[0-9]*\.[0-9]*)/', $return, $matches
                                );