Last modified: 2013-07-25 09:05:23 UTC
wfOutputHandler's $wgValidateAllHtml block uses apache_response_headers() which is not present in all SAPIs without checking if it exists. This leads to an error. However because wfOutputHandler is an output handler printing output is not permitted and the error that's triggered gets swallowed up.
*** Bug 48343 has been marked as a duplicate of this bug. ***
Patch in Gerrit change #63631.
IAlex: FYI, adding "bug: 48342" as the last line in your commit message will make the Gerrit bot automatically add a comment to the corresponding bug report, see http://www.mediawiki.org/wiki/Gerrit/Commit_message_guidelines