here's some more images that do the same trick:

http://commons.wikimedia.org/wiki/File:Regular_Octagon_Inscribed_in_a_Circle.gif'

http://commons.wikimedia.org/wiki/File:Approximated_Heptagon_Inscribed_in_a_Circle.gif

http://commons.wikimedia.org/wiki/File:Straight_Square_Inscribed_in_a_Circle.gif

Seems to indicate problems with a specific set of images. Have temporary deleted these. Some indications that it is only the old filerevisions that are causing this, not their last file revision...

Still shouldn't deadlock ImagaMagick of course...

Those are all animated gifs.

From looking at the backtrace, it may be trying to throw the "Error creating thumbnail: convert: UnableToAcquireString `' @ fatal/string.c/AcquireString/126." message, which is what I get with a large $wgMaxAnimatedGifArea (not with the standard 1.25e7 which WMF seem to be using...).

These processes shouldn't deadlock anymore, with Tim's latest changes. I have restored the first image (for debug purposes) and restored the other images as well, but have left their 'old versions' deleted, because they are apparently causing the problems with imagemagick.

Created attachment 7654
broken animated gif

This is the animated gif that isn't being recognized as animated by mediawiki, and was causing the convert problems, probably because the maxarea setting wasn't triggered.

Attached:

I have now also deleted the old revisions of the first image and uploaded one of these revisions to this bug. The error report on the image was: Error retrieving thumbnail from scaling server: Operation timed out after 53000 milliseconds with 0 bytes received

I'll see what I can reproduce on my local test server

It was locally recognised for me. I wonder if the detection failed because the metadata in the db is old, from a time (or bug) where we didn't properly detect that.