MimeAnalyzer::doGuessMimeType() uses XmlTypeCheck to find the type of a file. When the file does not contain XML data (e.g JPEG data) the following is emitted:
PHP Warning: XMLReader::open(): Unable to open source data
Surrounding the call to XmlTypeCheck with
MediaWiki\suppressWarnings(); $xml = new XmlTypeCheck( $file ); MediaWiki\restoreWarnings();
solves the problem.
Change 374039 had a related patch set uploaded (by MarkAHershberger; owner: MarkAHershberger):
[mediawiki/core@REL1_28] "PHP Warning: XMLReader::open(): Unable to open source data" on JPG data
Change 374041 had a related patch set uploaded (by MarkAHershberger; owner: MarkAHershberger):
[mediawiki/core@master] "PHP Warning: XMLReader::open(): Unable to open source data" on JPG data
Change 374039 abandoned by Reedy:
"PHP Warning: XMLReader::open(): Unable to open source data" on JPG data
Reason:
REL1_28 is EOL
Change 374041 abandoned by markahershberger:
"PHP Warning: XMLReader::open(): Unable to open source data" on JPG data