Thread:Project:Support desk/Issue with autorotation of thumbs on FF26.0 and MW1.21.4

Since version 26.0 Firefox considers the exif orientation flag of pictures. There still seem to be issues on the side of FF but there is a behaviour I cannot correctly interpret and which seems to be related to MW I guess. The given picture was take with the camera rotated by 90° and afterwards uploaded as usual with correct orientation. In case it is embedded not thumbed on a page it is being shown correctly for logged-in users as well as anonymous users. In case it is embedded on a page as a thumb it gets rotated by 90°, however *only* for logged-in users. The latter behaviour makes me ask here: Does this qualify for a bug report on bugzilla? I guess so since I think that treating logged-in users different from anonymous users appears to be a MW thing to me. The "funny" thing is that the thumbed image preview in namespace file is correct for both logged-in users as well as anonymous users. Setting "$wgEnableAutoRotation" to "false" did not help but only adding the image parameter "upright". This issue already appeared in MW1.21.3