Commit 1fb20f0ab9f1b1ad51a79dbf59c50db5cc91d6f9
2018-10-18T23:38:27
cocoa: Put a mutex around GL_SwapBuffers. Prevents deadlock when swapping two different GL contexts on two different threads at the same time on macOS 10.14 ("Mojave"). Fixes Bugzilla #4278.