Right now, the URIs of a principal are not guaranteed immutable. They should be.

This uses an API I'm adding in bug 336699

Comment on attachment 223934 [details] [diff] [review] Patch i wonder if we should be worried about the additional perf overhead of the NS_EnsureSafeToReturn calls. if we can make mURI immutable, then we shouldn't need to anything more than just AddRef it, but here we are adding a call to check if it is immutable each time we try to get it.

I _think_ getting the URI from a principal is not on any too-critical paths. But yeah, if it turns out it's a problem we may have to store a local boolean as to whether NS_TryToSetImmutable succeeded or something. Other than that, the only way faster than what we do now (QI plus call) would be to store some out-of-band state in a member, or store some object that's an "nsIURI plus whether we set it immutable" or something. :(

Comment on attachment 223948 [details] [diff] [review] Updated to final patch from bug 336699 r=dveditz

Fixed on trunk.