Shouldn't the block be copied?

The block documentation says "You only need to make a copy when you expect the block to be used after destruction of the scope within which it was declared." That seems to be the case here. `beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo:` exits, allowing the block to go out of scope, before the completion block runs.

Start at the implementation of beginSheetModalForWindow:modalDelegate:didEndSelector:contextInfo: and compare its block lifetime with the documentation quoted in the report. Inspect the completion-block path and verify that the block remains valid after the method returns; done means the behavior is consistent with the documented lifetime.

Written by the indexing model from the issue text.