Last modified: 2010-05-15 15:54:50 UTC
This bug came to light with [https://bugzilla.wikimedia.org/show_bug.cgi?id=14867 Bug 14867]. Setting $wgFeedDiffCutoff = 0 does inhibit display of diffs on RSS feeds, but does not stop internal generation of diffs. Normally, this would not be noticed except when there is a problem with the DifferenceEngine and it takes 20 to 30 seconds for a diff on a pathological case. Depending on max_execution_time on the server, this will cause timeouts and HTTP 500 errors. Thus, RSS feeds get broken.
Fixed in r38897