Don't treat configured but absent engine as executable
authorMax Semenik <maxsem.wiki@gmail.com>
Fri, 4 Mar 2016 19:21:53 +0000 (11:21 -0800)
committerMax Semenik <maxsem.wiki@gmail.com>
Fri, 4 Mar 2016 23:06:39 +0000 (15:06 -0800)
commit44ed77c07ece4cd8ae34809850b1e74baee90b61
treec0b7289039aa796955aa882e181fae5da4bd62d6
parent356aea3ab66033587e2c476d5cf9dd71fc454896
Don't treat configured but absent engine as executable

E.g. if you have $wgExternalDiffEngine = 'wikidiff2' but after
a PHP update you no longer have the module you still shouldn't attempt
to shell out to some nonexistent wikidiff2.

Bug: T74030
Change-Id: I745cd1cb2e152f4fbb95c8f782d70117f8c844f1
includes/diff/DifferenceEngine.php