menu thread lockup when using cursor key on empty folder

[Ziusudra]

Use mouse to open a Tracker or Deskbar menu to an empty folder then press cursor up or down key. Thread will deadlock and next interaction with app will cause it to deadlock.

[Ziusudra]

gdb backtraces

[stippi]

It just so happens that I came across a method in the Menu tracking code that I thought was curious and should deadlock in certain situations. And indeed there is a ticket within the next day... :-)

(gdb) bt
#0  0x002fc0c7 in BMenu::_NextItem () from /boot/system/lib/libbe.so
#1  0x002fd4d7 in BMenu::_SelectNextItem () from /boot/system/lib/libbe.so
#2  0x002feb8c in BMenu::KeyDown () from /boot/system/lib/libbe.so
#3  0x00365984 in BWindow::DispatchMessage () from /boot/system/lib/libbe.so
#4  0x00309343 in BPrivate::BMenuWindow::DispatchMessage () from /boot/system/lib/libbe.so
#5  0x00361de9 in BWindow::task_looper () from /boot/system/lib/libbe.so
#6  0x002ade0e in BLooper::_task0_ () from /boot/system/lib/libbe.so
#7  0x005eee6c in thread_entry () from /boot/system/lib/libroot.so
#8  0x78594fec in ?? ()

When the method has no other item to go to, it will loop forever.

[stippi]

Not deadlock, I mean busy-loop... sorry.

[stippi]

Fixed in hrev36813. I've also noticed the cached menu window thread can deadlock when trying to close a submenu by pressing Esc. That's a different issue, though.