NSBrowser Column Resizing Causes NSWindowWillStartLiveResizeNotification to be posted even though the window isn't being resized.

I have an NSBrowser inside a window. When I start resizing a column I noticed a peculiar behavior: it causes NSWindowWillStartLiveResizeNotification to get posted for the NSWindow the browser is inside (and did end gets posted when column resizing finishes). The browser is not the NSWindow contentView but a descendant of the contentView.

I have my reasons for caring (I'm currently listening for these window resize notifications) but my code naively assumes that NSWindowWillStartLiveResizeNotification - NSWindowDidEndLiveResizeNotification indicates a window resizing session, not a column resizing session for the NSBrowser.

This is in contrast to NSOutlineView. When resizing columns in NSOutlineView the window resize notifications do not get posted.

NSBrowser deliberately kicks it off:

-[NSWindow _startLiveResize];

-[NSBrowser _resizeColumn:withEvent:] ()

So this seems quite intentional but is it necessary in modern macOS? Should I file a bug? I already did

FB20298148

NSBrowser Column Resizing Causes NSWindowWillStartLiveResizeNotification to be posted even though the window isn't being resized.
 
 
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