Comment 9 for bug 294712

Created an attachment (id=303675)
Patch (v3)

This patch handles all this in the context menu code. It checks both permissions.default.image and the permission for the host the image is coming from. If any of them would cause the image not to load, the code flips it and then restores the original value when the nsIImageLoadingContent::forceReload() call returns.

This should address bz's concerns. Off to gavin for review.