StyleSetImpl::EnableQuirkStylesheet holds its static nsIURI url defined at http://lxr.mozilla.org/seamonkey/source/layout/base/src/nsStyleSet.cpp#604 past XPCOM shutdown, leaking 1 nsStdURL (and some other things it owns, I think).

That's Marc's.

The leak is a nuisance, but it causes no harm since the memory is used until the program ends. I will change the code to use a member-variable to hold the URI as a COMPtr so that it does not show up as a leak and clutter the leak report, however that means we will have to create a new instance every time there is a new StyleSet created, which will make it slower (immeasurably, I believe).

David, can you check the patch I attached and tell me what you think? Thanks.

Looks reasonable to me. Since we only create 8 nsStyleSet over the life of the browser when running the bloat tests it doesn't look like much performance cost. (If it were, or if you think it is, significant then you could hold a global variable counting the number of nsStyleSet, make the URI static, and release it when the count goes to 0.) The one thing that seems a little strange is putting a function call inside a macro (NS_SUCCEEDED). It's OK in this particular case, but I'd think it's bad style. If I count as a reviewer (which I'm never completely sure of...) then r=dbaron (including if you change the NS_SUCCEEDED to 2 steps).

Marking as a dup of 43656 since Inaky has a handle on a fix that will make the erported leak go away and will keep the URL instance static. David, I'll add you to the CC on that one so you can continue to track it. *** This bug has been marked as a duplicate of 43656 ***

Verified dupe, particularly as the entire discussion in this bug seem to have moved over to 43656.