Bastien Montagne
8e0f8bb3e1
Some notes: * `Image.cache` acts as some kind of 'main' cache, when it is NULL (could not be restored), other caches should also be cleared. Oddly enough, previous code was not clearing **all** caches, could not find any reason for that behavior, so new code does a full clear. * `imamap` is still used for Node previews from scenes' compositor, however this is actually fully disabled in `direct_link_node()`. * For render slots we cannot use offsetof as third part of the cache key, so we are using a hash of the slot's name instead. As far as I can tell, this fixes T76989: Visual glitches when undo after reload multiple images by script (in Material Preview).