If you register an extension by creating a text file in profile/extensions/ pointing to the extension location, and then remove install.rdf at that location, EM deletes the whole extension directory. I can see the reasoning behind this. I argue this should not be done though. One of applications for this feature (ability to easily register files in location outside user's profile), as I see it, is using it to develop extensions, in a location separate from your profile. That allows to test the same latest code in different profiles (e.g. sometimes you want to check the behavior of your extension on a clear profile or when it runs with another extension). It also allows you to have shorter path to your extension, e.g. "x:\dev\extension" instead of "c:\profile\extensions\guid\chrome" or even "c:\documents & settings\name\application data\mozilla\firefox\profile\extensions\guid\chrome". So, one stores all of his project files (including those not directly used by firefox) in a single directory, which happens to also contain install.rdf. (That's what I've been doing for quite a long time, first by editing chrome.rdf, then using absolute paths in chrome.manifest). Then he decides to temporarily rename/move install.rdf and - oops - all of the project files are gone. I was lucky enough to be using CVS for that project, but you're responsible for deleting my todo file and archive of releases ;-) The main reason I think EM shouldn't do this is that it /didn't create/ the directory referenced in the GUID file. Generally, software shouldn't delete what it didn't create. I can understand deleting folders like profile/extensions/{GUID} on uninstall. They are in Firefox's profile and usually it created it on installation. But the folders referenced from a text-file there do not "belong" to Firefox, therefore it has no right to delete them. I hope you can see my point.

Yes, this is not the intended behavior.

Fixed by patch in 291831

Also if you uninstall the extension using FF Extension Manager the development directory gets deleted. You need some way to destinguish development from regular installs. I got caught because I was about to package the directory, so I removed the extension so that I could re-install a jar version. This will be normal usage. (I had a backup phew!)

Peter, that's a different issue, please file a separate bug if you are sure you can reproduce it with a recent build.