User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:29.0) Gecko/20100101 Firefox/29.0 (Beta/Release) Build ID: 20140506152807 Steps to reproduce: This problem was fixed for a couple of years, and has reared its ugly head again in 29.0.0 and 29.0.1. MacOS 10.8.5. (1) browse. Happens occasionally even with very short browsing sessions. (2) Command-Q Quit Firefox. Actual results: When Privacy Clear History when Firefox Closes is checkmarked, and the Offline Website Data setting is selected, Firefox regularly hangs (Application Not Responding) and can only be halted in MacOS with the command-option-escape Force Quit. The same happens on the next use, unless Advanced Network pane Offline Web Content and User Data "Clear Now", after which it quits cleanly. Sometimes it requires Cached Web Content "Clear Now" as well. Expected results: Quit. Yes, I've read all the related bugs and this particular issue isn't found. There are an awful lot of outstanding related tickets.... Bug 483013 - (cmd-q) [Tracking]

Whatever is happening, I can reproduce with no sessions at all! (1) General Startup "show a blank page" + Privacy History "Clear history when Firefox closes" (2) quit (3) start (4) command-Q Note this only hangs sometimes. But nothing what-so-ever should have been loaded.... There shouldn't be anything in the cache, but it's looping trying to remove something somewhere!