606309 - Image cache hands out stale data on a temporary basis

Status: NEW

(Core :: Graphics: ImageLib, defect)

Description

[Boris Zbarsky [:bzbarsky]]

For images with unknown expiry LoadImage hands back the cached image for the url, whatever that is, then goes off and validates it.  And if it comes back valid we're done, and otherwise it switches around the imgRequest the imgRequestProxy points to.

Which means we draw the stale image while it's being validated, then switch to it.  That's really bizarre behavior that none of our other caches have.  Ideally, we'd just show nothing until the new image comes in or some such.  Possibly on a per-document basis?