Virtualbox crash in VBoxDD!VBoxUsbRegister

[Mihai Hanor]

This is an older crash, which I didn't understood until I VB 3.2.6 beta2. I think I first mentioned about it in #6443. Now, I can reproduce it at will. Similarly with the QtGuiVBox4!QWidget::repaint+0x5dcb crash, the reproduction steps of this one may not seem to have anything to do with the normal usage of the program.

All that is required is one click on the X button (close window button) of a VM window, at the right moment. Reproducing it at will, requires you to be relatively fast and to be able to intuit when to act (timing is important). It always crashes in VBoxDD!VBoxUsbRegister plus some offset (depending on the guest type).

Host: Windows XP SP3 32bit
Affected versions: VB 3.2.4, VB 3.2.6 beta1 and beta2

First test case: guest Windows 7 32 bit
The hot moment is at boot time, right before the guest switches from text mode (80x25 I think, empty screen, text cursor positioned in the top left corner) to 1024x768 graphics (for the eye-kandy animated boot logo).

Second test case: guest Windows XP 32 bit
The moment you're looking for is also at boot time, right before the guest switches from text mode (it has completed the text mode progress bar) to the 640x480/800x600 graphics (for boot logo and animated progress bar).

Technique:

1. Press the X button with the mouse cursor. The top-most window "Close Virtual Machine" appears.
2. Press Esc on the keyboard. The "Close Virtual Machine" window closes. Again, with a fast action, press the X button on the VM window. You must time it correctly, not too fast (the button will not "catch" it) and not too late, or you'll miss the right moment. Repeat if you have not missed it (the guest switched to the 2nd resolution). You can rest while the "Close Virtual Machine" is being displayed, but the "Esc followed by click on X" succession must be fast. Or you can crash it the first time if you're lucky or if you're able to time it correctly.