>...at least not on Mojave.
I don't think you can get there from here...I'd speculate it's working as expected.
From the linked docs:
"This function is provided for compatibility support between Core Text and clients needing to support QuickDraw-style font references. QuickDraw is a deprecated technology in macOS 10.4 and later."
I'd suggest testing on macOS <10.4 to see if it's ok there, and also file a bug and see what comes back.
Thanks for the reply.
I understand that QuickDraw itself is deprecated. Though it does still work in a 32-bit app on Mojave, even though it's completely impossible to use those old APIs in a 64-bit app built in Xcode 10.
But as far as I can tell, there's nothing to indicate that the CTFontCreateWithQuickdrawInstance function is deprecated. If it were, it would be annotated with __OSX_AVAILABLE_BUT_DEPRECATED, but it's not, and I get no warning when targeting 10.14. So I think your speculation that it shouldn't work is unwarranted.
Furthermore, to me, the link you quote reinforces my contention that this function should work as I expect. I'm not trying to use QuickDraw, I'm trying to resolve an old QuickDraw-style font reference, and compatibility support between Core Text and that old name is exactly what I need.
I don't have a system earlier than 10.9 to test with. Older versions of our software ran on those older versions of OS X, and even back to the OS 9 / Classic days, but the whole point here is that I need a way to resolve the old font name retrieved with the older APIs to a font I can use with new APIs.
My question still stands.
If the underlying support is MIA (example Mojave), when coupled with a supported non-deprecated call the result will be null - expected behavior. My assertion still stands.