I never use that feature, and have it turned off at all times too... but... after reading this post and looking at both original and patched code, I am confused as to what is the purpose and the correct (expected) behaviour of that list?
Before, it was clearing the list every time some editor (no matter which) was closed. Now it clears the list when the last open editor is closed. If any editor (even if containing a file that belongs to a different project or no project at all) is open, it is not cleared.
Before the patch, it would clear the list at inappropriate times, which is not good. After the patch it (almost) never clears that list. That is somewhat better than having an empty list 80% of the time, but it is what is wanted? I imagine people want to see exactly the functions which are in the files they have open, not any other files. Is that correct?