The issue is a combination of following aspects:
- Missing null-pointer check in the image operation, which is probably
why the result was buggy. It is addressed by #123493.
- In certain conditions loading image was wrongfully failing.
The reason for failing to read image were items with a null-pointer
image buffer left by the cache limit enforcer, which was considered
to be an indication of failed load from disk. The reason why the cache
limiter leaves items with null-ptr as an image buffer is kind of a
legacy limitation which was never resolved. Long story short: the
system expects put() to be called on the cache to clear its empty
items.
To solve the original issue of files considered to be unreadable
only set the cache-empty if the image buffer was added empty.
Pull Request: https://projects.blender.org/blender/blender/pulls/123496
a13a116de9