I'm using a fresh build (after the xpcom2 landing). I go to the preference panel and change a preference. Then hit OK. I get the following crash. NTDLL! 77f76148() nsDebug::PreCondition(char * 0x0170fe84, char * 0x0170fe74, char * 0x0170fe40, int 31) line 122 + 13 bytes nsBaseWidget::Release(nsBaseWidget * const 0x02f67c54) line 31 + 38 bytes nsWebShell::~nsWebShell() line 553 + 27 bytes nsWebShell::`scalar deleting destructor'(unsigned int 1) + 15 bytes nsWebShell::Release(nsWebShell * const 0x02f66a50) line 633 + 95 bytes PresShell::HandleEvent(PresShell * const 0x02cef4d4, nsIView * 0x02c34970, nsGUIEvent * 0x0012e060, nsEventStatus & nsEventStatus_eConsumeDoDefault) line 2034 + 18 bytes nsView::HandleEvent(nsView * const 0x02c34970, nsGUIEvent * 0x0012e060, unsigned int 8, nsEventStatus & nsEventStatus_eConsumeDoDefault, int & 0) line 833 nsView::HandleEvent(nsView * const 0x02cfed90, nsGUIEvent * 0x0012e060, unsigned int 8, nsEventStatus & nsEventStatus_eConsumeDoDefault, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cfd5b0, nsGUIEvent * 0x0012e060, unsigned int 8, nsEventStatus & nsEventStatus_eConsumeDoDefault, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cfd4e0, nsGUIEvent * 0x0012e060, unsigned int 8, nsEventStatus & nsEventStatus_eConsumeDoDefault, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cef120, nsGUIEvent * 0x0012e060, unsigned int 28, nsEventStatus & nsEventStatus_eConsumeDoDefault, int & 0) line 818 nsViewManager::DispatchEvent(nsViewManager * const 0x02cefa00, nsGUIEvent * 0x0012e060, nsEventStatus & nsEventStatus_eConsumeDoDefault) line 1733 HandleEvent(nsGUIEvent * 0x0012e060) line 67 nsWindow::DispatchEvent(nsWindow * const 0x02c34a44, nsGUIEvent * 0x0012e060, nsEventStatus & nsEventStatus_eIgnore) line 410 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012e060) line 431 nsWindow::DispatchStandardEvent(unsigned int 104) line 446 + 15 bytes nsWindow::DispatchFocus(unsigned int 104) line 2959 + 12 bytes nsWindow::ProcessMessage(unsigned int 8, unsigned int 656596, long 0, long * 0x0012e1d8) line 2313 + 19 bytes nsWindow::WindowProc(void * 0x000d04f0, unsigned int 8, unsigned int 656596, long 0) line 474 + 27 bytes USER32! 77e71ab7() USER32! 77e71a77() NTDLL! 77f7624f() nsWindow::~nsWindow() line 150 ChildWindow::~ChildWindow() + 15 bytes ChildWindow::`scalar deleting destructor'() + 15 bytes nsBaseWidget::Release(nsBaseWidget * const 0x02f67c54) line 31 + 99 bytes nsWebShell::~nsWebShell() line 553 + 27 bytes nsWebShell::`scalar deleting destructor'(unsigned int 1) + 15 bytes nsWebShell::Release(nsWebShell * const 0x02f66a50) line 633 + 95 bytes PresShell::HandleEvent(PresShell * const 0x02cef4d4, nsIView * 0x02c34970, nsGUIEvent * 0x0012e614, nsEventStatus & nsEventStatus_eIgnore) line 2034 + 18 bytes nsView::HandleEvent(nsView * const 0x02c34970, nsGUIEvent * 0x0012e614, unsigned int 8, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 833 nsView::HandleEvent(nsView * const 0x02cfed90, nsGUIEvent * 0x0012e614, unsigned int 8, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cfd5b0, nsGUIEvent * 0x0012e614, unsigned int 8, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cfd4e0, nsGUIEvent * 0x0012e614, unsigned int 8, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 818 nsView::HandleEvent(nsView * const 0x02cef120, nsGUIEvent * 0x0012e614, unsigned int 28, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 818 nsViewManager::DispatchEvent(nsViewManager * const 0x02cefa00, nsGUIEvent * 0x0012e614, nsEventStatus & nsEventStatus_eIgnore) line 1733 HandleEvent(nsGUIEvent * 0x0012e614) line 67 nsWindow::DispatchEvent(nsWindow * const 0x02c34a44, nsGUIEvent * 0x0012e614, nsEventStatus & nsEventStatus_eIgnore) line 410 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012e614) line 431 nsWindow::DispatchMouseEvent(unsigned int 301, nsPoint * 0x00000000) line 2881 + 15 bytes nsWindow::ProcessMessage(unsigned int 514, unsigned int 0, long 589843, long * 0x0012e790) line 2243 + 24 bytes nsWindow::WindowProc(void * 0x000d04f0, unsigned int 514, unsigned int 0, long 589843) line 474 + 27 bytes

Also crashes on Windows 98. A talkback report was sent but it apparently hasn't shown up at cyclone yet (reported using 'cpratt@netscape.com'). Additionally, some prefs which should already be set aren't.

cc:'ing mcmullen. Also happens on Mac.

This is not about changing prefs. It is about closing the prefs window. So I changed the summary accordingly. Copying danm, since this looks like a zombie of a big bug that I thought we had fixed.

As John says, setting a preference is completely unnecessary to reproduce this bug. "Close while crashing" is going to be a common symptom of a variety of bugs. This time, it was because of the crazy straw we start honking on when we hit the webshell's destructor. I've moved the destructor reentrancy protection up a little earlier. Actually, fixing this bug just uncovers another very similar crash in prefscore. But you didn't hear me say that.

Not crashing using the 1999060108 build under NT. Marking verified fixed.

Bulk move of all Pref UI component bugs to new Preferences component. Pref UI component will be deleted.