User-Agent: Mozilla/5.0 (Windows; U; Win98; de-DE; rv:1.7.6) Gecko/20050321 Firefox/1.0.2 Build Identifier: Mozilla/5.0 (Windows; U; Win98; de-DE; rv:1.7.6) Gecko/20050321 Firefox/1.0.2 After installing and removing some extesions I recognized that theire entries in about:config aren't removed. Reproducible: Always Expected Results: Remove the old extension entries in about:config

Maybe related: bug 286380 & bug 248298 May well be resolved by bug 286034

no, this is pure and simple preferences stuff, prefs set to anything but the defaults will be saved in prefs.js, and show up in about:config, whether or not the underlying code still exists. Short of modifying uninstall to require a list of possible preferences to reset, there isn't much in the way of "fixing" this. Also, this is considered useful in cases where an extension needs to be reinstalled, as the user does not need to reconfigure their extension from scratch. -> trivial, this is cosmetic and hidden from normal users, and may be a WONTFIX, since we have the same problem with obsolete prefs from old versions, but there's no real penalty from that.

But you have to mind the massive amount of old prefs if the user installs and delets many extensions.

it doesn't affect real-world performance to have unused prefs. Possibly if you got to a thousand or more there might be a measureable increase in memory, but to hit something actually user-perceptible would be much higher.

ok so close this bug, then.

*** This bug has been marked as a duplicate of 258301 ***

sorry for bugspam, long-overdue mass reassign of ancient QA contact bugs, filter on "beltznerLovesGoats" to get rid of this mass change