Needed a scrollbar in the sidebar to reproduce bug #17146. Initially was OK, but when I shrunk the window a second time, I crashed with this stack trace: FixedTableLayoutStrategy::AssignPreliminaryColumnWidths(int 6000) line 122 + 15 bytes BasicTableLayoutStrategy::Initialize(nsSize * 0x00000000, int 1, int 6000) line 112 nsTableFrame::BalanceColumnWidths(nsIPresContext & {...}, const nsHTMLReflowState & {...}, const nsSize & {...}, nsSize * 0x00000000) line 2890 nsTableFrame::Reflow(nsTableFrame * const 0x02a0e1e0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 1291 nsTreeFrame::Reflow(nsTreeFrame * const 0x02a0e1e0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 330 + 25 bytes nsContainerFrame::ReflowChild(nsIFrame * 0x02a0e1e0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes nsTableOuterFrame::Reflow(nsTableOuterFrame * const 0x02a0e9c0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 900 + 34 bytes nsBlockReflowContext::ReflowBlock(nsIFrame * 0x02a0e9c0, const nsRect & {...}, int 0, int 0, int 1, nsMargin & {...}, unsigned int & 0) line 251 + 45 bytes nsBlockFrame::ReflowBlockFrame(nsBlockReflowState & {...}, nsLineBox * 0x02a27680, int * 0x0012c82c) line 3226 + 59 bytes nsBlockFrame::ReflowLine(nsBlockReflowState & {...}, nsLineBox * 0x02a27680, int * 0x0012c82c, int 0) line 2614 + 20 bytes nsBlockFrame::ReflowDirtyLines(nsBlockReflowState & {...}) line 2425 + 27 bytes nsBlockFrame::Reflow(nsBlockFrame * const 0x02a0d420, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 1489 + 15 bytes nsBoxFrame::FlowChildAt(nsIFrame * 0x02a0d420, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsCalculatedBoxInfo & {...}, int & 0, nsString & {...}) line 1072 nsBoxFrame::FlowChildren(nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsRect & {...}) line 646 nsBoxFrame::Reflow(nsBoxFrame * const 0x00e18d88, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 508 nsContainerFrame::ReflowChild(nsIFrame * 0x00e18d88, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes RootFrame::Reflow(RootFrame * const 0x02a0cd70, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 332 nsContainerFrame::ReflowChild(nsIFrame * 0x02a0cd70, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes ViewportFrame::Reflow(ViewportFrame * const 0x02a0b110, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 514 PresShell::ResizeReflow(PresShell * const 0x029d9f10, int 6000, int 660) line 1082 PresShell::ResizeReflow(PresShell * const 0x029d9f14, nsIView * 0x029da310, int 6000, int 660) line 2466 nsViewManager::SetWindowDimensions(nsViewManager * const 0x029d8160, int 6000, int 660) line 378 nsViewManager::DispatchEvent(nsViewManager * const 0x029d8160, nsGUIEvent * 0x0012d6d0, nsEventStatus & nsEventStatus_eIgnore) line 1603 HandleEvent(nsGUIEvent * 0x0012d6d0) line 67 nsWindow::DispatchEvent(nsWindow * const 0x029da1d4, nsGUIEvent * 0x0012d6d0, nsEventStatus & nsEventStatus_eIgnore) line 407 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012d6d0) line 428 nsWindow::OnResize(nsRect & {...}) line 3333 + 15 bytes nsWindow::ProcessMessage(unsigned int 71, unsigned int 0, long 1235244, long * 0x0012d8bc) line 2762 + 24 bytes nsWindow::WindowProc(HWND__ * 0x0008024a, unsigned int 71, unsigned int 0, long 1235244) line 585 + 27 bytes USER32! 77e719d0() USER32! 77e730a3() NTDLL! 77f763a3() DocumentViewerImpl::SetBounds(DocumentViewerImpl * const 0x029914d0, const nsRect & {...}) line 479 nsWebShell::SetBounds(nsWebShell * const 0x02996e30, int 0, int 0, int 400, int 44) line 1230 nsHTMLFrameInnerFrame::Reflow(nsHTMLFrameInnerFrame * const 0x02991170, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 911 nsContainerFrame::ReflowChild(nsIFrame * 0x02991170, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes nsHTMLFrameOuterFrame::Reflow(nsHTMLFrameOuterFrame * const 0x02991550, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 362 nsBoxFrame::FlowChildAt(nsIFrame * 0x02991550, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsCalculatedBoxInfo & {...}, int & 0, nsString & {...}) line 1072 nsBoxFrame::FlowChildren(nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsRect & {...}) line 646 nsBoxFrame::Reflow(nsBoxFrame * const 0x0253b710, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 508 nsBoxFrame::FlowChildAt(nsIFrame * 0x0253b710, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsCalculatedBoxInfo & {...}, int & 0, nsString & {...}) line 1072 nsBoxFrame::FlowChildren(nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsRect & {...}) line 646 nsBoxFrame::Reflow(nsBoxFrame * const 0x025380f0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 508 nsBoxFrame::FlowChildAt(nsIFrame * 0x025380f0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsCalculatedBoxInfo & {...}, int & 0, nsString & {...}) line 1072 nsBoxFrame::FlowChildren(nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsRect & {...}) line 646 nsBoxFrame::Reflow(nsBoxFrame * const 0x025365e8, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 508 nsBoxFrame::FlowChildAt(nsIFrame * 0x025365e8, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsCalculatedBoxInfo & {...}, int & 1, nsString & {...}) line 1072 nsBoxFrame::FlowChildren(nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0, nsRect & {...}) line 646 nsBoxFrame::Reflow(nsBoxFrame * const 0x00ebfdf0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 508 nsContainerFrame::ReflowChild(nsIFrame * 0x00ebfdf0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes RootFrame::Reflow(RootFrame * const 0x028ac3d0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 332 nsContainerFrame::ReflowChild(nsIFrame * 0x028ac3d0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 405 + 31 bytes ViewportFrame::Reflow(ViewportFrame * const 0x028ac6c0, nsIPresContext & {...}, nsHTMLReflowMetrics & {...}, const nsHTMLReflowState & {...}, unsigned int & 0) line 514 PresShell::ResizeReflow(PresShell * const 0x0233b160, int 6540, int 3075) line 1082 PresShell::ResizeReflow(PresShell * const 0x0233b164, nsIView * 0x0233b540, int 6540, int 3075) line 2466 nsViewManager::SetWindowDimensions(nsViewManager * const 0x0233ba40, int 6540, int 3075) line 378 nsViewManager::DispatchEvent(nsViewManager * const 0x0233ba40, nsGUIEvent * 0x0012f560, nsEventStatus & nsEventStatus_eIgnore) line 1603 HandleEvent(nsGUIEvent * 0x0012f560) line 67 nsWindow::DispatchEvent(nsWindow * const 0x0233b404, nsGUIEvent * 0x0012f560, nsEventStatus & nsEventStatus_eIgnore) line 407 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012f560) line 428 nsWindow::OnResize(nsRect & {...}) line 3333 + 15 bytes nsWindow::ProcessMessage(unsigned int 71, unsigned int 0, long 1243068, long * 0x0012f74c) line 2762 + 24 bytes nsWindow::WindowProc(HWND__ * 0x0002017a, unsigned int 71, unsigned int 0, long 1243068) line 585 + 27 bytes USER32! 77e719d0() USER32! 77e730a3() NTDLL! 77f763a3() DocumentViewerImpl::SetBounds(DocumentViewerImpl * const 0x02283170, const nsRect & {...}) line 479 nsWebShell::SetBounds(nsWebShell * const 0x022c2450, int 0, int 0, int 436, int 205) line 1230 nsWebShellWindow::HandleEvent(nsGUIEvent * 0x0012f94c) line 532 nsWindow::DispatchEvent(nsWindow * const 0x022b6444, nsGUIEvent * 0x0012f94c, nsEventStatus & nsEventStatus_eIgnore) line 407 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012f94c) line 428 nsWindow::OnResize(nsRect & {...}) line 3333 + 15 bytes nsWindow::ProcessMessage(unsigned int 71, unsigned int 0, long 1244072, long * 0x0012fb38) line 2762 + 24 bytes nsWindow::WindowProc(HWND__ * 0x00070146, unsigned int 71, unsigned int 0, long 1244072) line 585 + 27 bytes USER32! 77e719d0() USER32! 77e730a3() NTDLL! 77f763a3() USER32! 77e718d2() USER32! 77e727fe() USER32! 77e72889() nsWindow::WindowProc(HWND__ * 0x00070146, unsigned int 274, unsigned int 61448, long 22282674) line 592 + 31 bytes USER32! 77e719d0() USER32! 77e71982() NTDLL! 77f763a3() USER32! 77e718d2() USER32! 77e727fe() USER32! 77e72889() nsWindow::WindowProc(HWND__ * 0x00070146, unsigned int 161, unsigned int 17, long 22282674) line 592 + 31 bytes USER32! 77e71820() MIME! 015401b2()

I can't reproduce this on a 11/9 debug NT build. I don't think the sidebar supports horizontal scroll bars, since shrinking it didn't produce one. I resized the app to get a horizontal scroll bar on the document but had no crash.

Download the 1999-11-09-11 build from sweetlou and install via seamonkey32e.exe. run it use sidebar customize to remove what's related panel open bookmarks panel use VERTICAL resize to shrink the window until bookmarks has a VERTICAL scrollbar scroll the knob into the middle of the range vertically resize the window back to its original size move the scrollbar knob (that shouldn't be there) CRASH. N.B. I am not shrinking the sidebar using the grippy, I am shrinking the entire browser window by moving the bottom toward the top. I've sent in a talkback report, but the talkback interface went away before I could see if it gave me an ID. Anyway, it was filed today. This is 100% reproducible following the steps just outlined.

Clearing WORKSFORME Resolution due to reopen of this bug.

Using an 11/10 debug WinNT build I'm seeing a different stack. Peter, even if I had seen the original stack, I think it involves trees. nsXULDocument::AttributeChanged(nsXULDocument * const 0x02691cb0, nsIContent * 0x0264fef0, int 0, nsIAtom * 0x011b2d10 {"curpos"}, int -1) line 1194 + 25 bytes nsXULElement::SetAttribute(nsXULElement * const 0x0264fef0, int 0, nsIAtom * 0x011b2d10 {"curpos"}, const nsString & {"0"}, int 1) line 2147 nsSliderFrame::SetCurrentPosition(nsIContent * 0x0264fef0, nsIFrame * 0x0264ded0, int 0) line 681 + 36 bytes nsSliderFrame::HandleEvent(nsSliderFrame * const 0x0264cee0, nsIPresContext & {...}, nsGUIEvent * 0x0012fbe0, nsEventStatus & nsEventStatus_eIgnore) line 536 PresShell::HandleEvent(PresShell * const 0x026c3e74, nsIView * 0x0264ce50, nsGUIEvent * 0x0012fbe0, nsEventStatus & nsEventStatus_eIgnore) line 2417 + 38 bytes nsView::HandleEvent(nsView * const 0x0264ce50, nsGUIEvent * 0x0012fbe0, unsigned int 28, nsEventStatus & nsEventStatus_eIgnore, int & 0) line 838 nsViewManager::DispatchEvent(nsViewManager * const 0x026c04b0, nsGUIEvent * 0x0012fbe0, nsEventStatus & nsEventStatus_eIgnore) line 1743 HandleEvent(nsGUIEvent * 0x0012fbe0) line 67 nsWindow::DispatchEvent(nsWindow * const 0x026c01a4, nsGUIEvent * 0x0012fbe0, nsEventStatus & nsEventStatus_eIgnore) line 407 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012fbe0) line 428 nsWindow::DispatchMouseEvent(unsigned int 300, nsPoint * 0x00000000) line 3424 + 21 bytes ChildWindow::DispatchMouseEvent(unsigned int 300, nsPoint * 0x00000000) line 3642 nsWindow::ProcessMessage(unsigned int 512, unsigned int 1, long 13107356, long * 0x0012fdf0) line 2623 + 24 bytes nsWindow::WindowProc(HWND__ * 0x002a0800, unsigned int 512, unsigned int 1, long 13107356) line 585 + 27 bytes USER32! DispatchMessageWorker@8 + 135 bytes

reassigning to alecf, who is the current point man for tree bugs.

what window did you first see this in?

Just opened the browser to the default location. I did nothing special, although I may have had my home page set to NONE at the time.

ok, I think #18369, #18713, and #16929 are all related to the scrollbar going away due to a tree reflow, and then recieving events, probably all mouseups.

After further investigation, I've decided that they're all really dupes of each other. *** This bug has been marked as a duplicate of 16929 ***

Agreed. Marking as verified dup of 16929.