Protect QCoreApplication::notifyInternal2() against null receivers?

I was going through old crash logs and found the one attached that I had saved because it caused me annoying loss of data: crash-after-xrdb-on-remote-server.log

According to the notes I made this happened after I ran xmodmap on the external X11 server where the crashed application was being displayed (specifically to redefine the "mode_switch dead key" for entering accented characters).

The crash and loss of edited data could have been avoided if `QCoreApplication::notifyInternal2()` had had a nullptr check. I see that still isn't the case, but with the other checks already in place this additional one wouldn't cause a measurable performance regression?