Since we started building our application on Tahoe, all NSPopupButtons in the UI stop truncating when the window they're in is moved to a different screen. Even though their frame is correct, if the selected item string is longer than what can fit, they just draw outside of their bounds, overlapping other neighbouring controls. This is reproducible only in our app target even though they are not subclassed or overridden in any way. The same window copied to a test app doesn't have the issue. Initially good After dragging to another screen Frame is correct in the View Hierarchy debugger, but the contents are incorrect. Very simple constraint setup, with content compression resistance set lower to allow resizing below the intrinsic content size. This is what happens on this simple test window. The rest of the popups in more complex windows are all bad right away, without requiring you to move them to a different screen. When built on Sequoia, all is well regardless of which OS the app is run on. Looking for ideas on how to troubleshoot this and figure out what's triggering it.

I've developed a new Quicklook data-based preview extension for a custom file type that generates an image preview of the file. I previously used a Quick Look generator plug-in but support for it was deprecated and now removed in macOS Sequoia. My app opens files using a open(url.path, O_RDWR | O_NONBLOCK | O_EXLOCK) call. The locking flags are used to prevent other clients from writing the file if it's already open. I discovered that when Finder is showing the “large” file previews (such as when in column or gallery modes) from a SMB share, the open call fails with EWOULDBLOCK as if the file is locked. It does work just fine on local files. Opening with O_SHLOCK also has the issue. Surprisingly it does work just fine for previews that return Plain Text data instead of Image data. Using the lsof command, it seems like the Quicklook process has some kind of lock on the file. This is the output of the lsof command: COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE QuickLook 48487 XXXX txt REG 1,15 125000611 3161369 Attached is a test project that tries a few different opening and locking functions. It also includes a test file and a sample image preview extension that displays a red square. When everything is working, regular console messages show the progress of the tests. When the file is on a SMB share and selected in Finder Gallery mode, the open test will fail with a fault message in the console. Notably, locking with flock works, which is weird because it should have similar semantics according to the man page for open(2). Filed this as FB15051186