I don't see any apps in that bug report, it's only about a test failure. Do you have real apps that trigger the problem in normal usage?
The two apps from #26997 #23756 use midiStream with DCB_CALLBACK_FUNCTION. They need patch 1+2.
I've not retested ff7 from bug #9220 which uses midiStream too.
The apps that would benefit from patch 1/2 alone are those that use midiStream with one of DCB_NULL, WINDOW or EVENT.
I've not investigated which MIDI apps are of the required kind or if they use mcimidi, midiOut directly or midiStream with DCB_FUNCTION.
Regards, Jörg Höhle