This commit fixes a consistent crash noticed when visiting a particular
profile.
The crash was occuring when trying to display the blurhash of a specific Event, where the metadata claimed the image dimensions were 0px x 0px.
The null dimensions caused a division by zero to occur when scaling the image down, yielding a NaN (Not a Number) size value, which crashed the app when trying to cast that CGFloat value down to an integer.
The crash was fixed by modifying the down-scaling computations to check for invalid dimensions, and return nil. The callers were then updated to fallback to a default display dimension.
Issue repro
-------
Device: iPhone 15 simulator
iOS: 17.5
Damus: dba1799df0
Steps:
1. Visit the profile npub1gujeqakgt7fyp6zjggxhyy7ft623qtcaay5lkc8n8gkry4cvnrzqd3f67z
2. Check accessing the profile does not crash Damus.
3. Visit the event that had invalid 0x0 dimensions on the metadata (note1qmqdualjezamcjun23l4d9xw7529m7fee6hklgtnhack2fwznxysuzuuyz)
4. Check that Damus does not crash.
Results: Steps 2 and 4 crash 100% of the time (3/3)
Testing
--------
PASS
Device: iPhone 15 simulator
iOS: 17.5
Damus: This commit
Steps: Same as repro
Results:
1. Crash no longer occurs
2. Blurhash looks ok
Closes: https://github.com/damus-io/damus/issues/2341
Changelog-Fixed: Fix crash when viewing notes with invalid image dimension metadata
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>
e70cfbbe63