Using a 02/16/99 SeaMonkey build, nsBlockFrame::RemoveChild() throws an assertion when the editor deletes a selected line via the DOM. This is a cross platform bug. Here's how to reproduce the assertion: - Start the Linux viewer with Example 0 - Select Tools->Editor Mode from the menus. - Select the entire first line of the document. - Hit any key. You should now crash with an assertion in nsBlockFrame::RemoveChild(): Program received signal SIGABRT, Aborted. 0x40cc56a1 in __kill () (gdb) where #0 0x40cc56a1 in __kill () #1 0x40cc54cf in raise (sig=6) at ../sysdeps/posix/raise.c:27 #2 0x40cc66df in abort () at ../sysdeps/generic/abort.c:83 #3 0x409bdb86 in nsDebug::Abort ( aFile=0x4048d48d "/usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp", aLine=3751) at /usr/people/kin/builds/raptor.02_16_99/mozilla/xpcom/src/nsDebug.cpp:85 #4 0x409bdbee in nsDebug::Break ( aFile=0x4048d48d "/usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp", aLine=3751) at /usr/people/kin/builds/raptor.02_16_99/mozilla/xpcom/src/nsDebug.cpp:100 #5 0x409bdd31 in nsDebug::Assertion (aStr=0x4048dda4 "bad continuation", aExpr=0x4048dd89 "child == line->mFirstChild", aFile=0x4048d48d "/usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp", aLine=3751) at /usr/people/kin/builds/raptor.02_16_99/mozilla/xpcom/src/nsDebug.cpp:132 #6 0x402d5773 in nsBlockFrame::RemoveChild (this=0x82008d8, aLines=0x8200c00, aChild=0x821fd70) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:3751 #7 0x402d5577 in nsBlockFrame::DeleteChildsNextInFlow (this=0x82008d8, aPresContext=@0x81979f0, aChild=0x8200ba0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:3701 #8 0x402f4f0c in nsInlineReflow::ReflowFrame (this=0xbfffc16c, aIsAdjacentWithTop=1, aMetrics=@0xbfffc040, aStatus=@0xbfffc0ac) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsInlineReflow.cpp:485 #9 0x402f48ea in nsInlineReflow::ReflowFrame (this=0xbfffc16c, aFrame=0x8200ba0, aIsAdjacentWithTop=1, aReflowStatus=@0xbfffc0ac) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsInlineReflow.cpp:270 #10 0x402d2af0 in nsBlockFrame::ReflowInlineFrame (this=0x82008d8, aState=@0xbfffc784, aLine=0x8200c00, aFrame=0x8200ba0, aKeepLineGoing=0xbfffc0ec) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:2408 #11 0x402d15c6 in nsBlockFrame::ReflowLine (this=0x82008d8, aState=@0xbfffc784, aLine=0x8200c00, aKeepReflowGoing=0xbfffc138) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1711 #12 0x402d0e25 in nsBlockFrame::ReflowDirtyLines (this=0x82008d8, aState=@0xbfffc784) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1466 #13 0x402cfdd1 in nsBlockFrame::Reflow (this=0x82008d8, aPresContext=@0x81979f0, aMetrics=@0xbfffcc88, aReflowState=@0xbfffcb1c, aStatus=@0xbfffcc38) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:915 #14 0x402d8022 in nsBlockReflowContext::ReflowBlock (this=0xbfffcc44, aFrame=0x82008d8, aSpace=@0xbfffccd0, aIsAdjacentWithTop=1, aComputedOffsets=@0xbfffcc28, aFrameReflowStatus=@0xbfffcc38) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockReflowContext.cpp:192 #15 0x402d2548 in nsBlockFrame::ReflowBlockFrame (this=0x81f1fe8, aState=@0xbfffd3c8, aLine=0x821e1e8, aKeepReflowGoing=0xbfffcd7c) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:2259 #16 0x402d14cb in nsBlockFrame::ReflowLine (this=0x81f1fe8, aState=@0xbfffd3c8, aLine=0x821e1e8, aKeepReflowGoing=0xbfffcd7c) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1677 #17 0x402d0e25 in nsBlockFrame::ReflowDirtyLines (this=0x81f1fe8, aState=@0xbfffd3c8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1466 #18 0x402cfdd1 in nsBlockFrame::Reflow (this=0x81f1fe8, aPresContext=@0x81979f0, aMetrics=@0xbfffd8cc, aReflowState=@0xbfffd760, aStatus=@0xbfffd87c) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:915 #19 0x402d8022 in nsBlockReflowContext::ReflowBlock (this=0xbfffd888, aFrame=0x81f1fe8, aSpace=@0xbfffd914, aIsAdjacentWithTop=1, aComputedOffsets=@0xbfffd86c, aFrameReflowStatus=@0xbfffd87c) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockReflowContext.cpp:192 #20 0x402d2548 in nsBlockFrame::ReflowBlockFrame (this=0x81f1ca0, aState=@0xbfffe00c, aLine=0x81f22b0, aKeepReflowGoing=0xbfffd9c0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:2259 #21 0x402d14cb in nsBlockFrame::ReflowLine (this=0x81f1ca0, aState=@0xbfffe00c, aLine=0x81f22b0, aKeepReflowGoing=0xbfffd9c0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1677 #22 0x402d0e25 in nsBlockFrame::ReflowDirtyLines (this=0x81f1ca0, aState=@0xbfffe00c) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:1466 #23 0x402cfdd1 in nsBlockFrame::Reflow (this=0x81f1ca0, aPresContext=@0x81979f0, aMetrics=@0xbfffe4f8, aReflowState=@0xbfffe3a0, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsBlockFrame.cpp:915 #24 0x402cd317 in nsAreaFrame::Reflow (this=0x81f1ca0, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe4f8, aReflowState=@0xbfffe490, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsAreaFrame.cpp:502 #25 0x402daf67 in nsContainerFrame::ReflowChild (this=0x81f1768, aKidFrame=0x81f1ca0, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe4f8, aReflowState=@0xbfffe490, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsContainerFrame.cpp:364 #26 0x402e7dbc in RootFrame::Reflow (this=0x81f1768, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe6e8, aReflowState=@0xbfffe62c, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsHTMLFrame.cpp:250 #27 0x402daf67 in nsContainerFrame::ReflowChild (this=0x81efe30, aKidFrame=0x81f1768, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe6e8, aReflowState=@0xbfffe62c, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsContainerFrame.cpp:364 #28 0x40302873 in nsScrollFrame::Reflow (this=0x81efe30, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe80c, aReflowState=@0xbfffe79c, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsScrollFrame.cpp:349 #29 0x402daf67 in nsContainerFrame::ReflowChild (this=0x81cbe90, aKidFrame=0x81efe30, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe80c, aReflowState=@0xbfffe79c, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsContainerFrame.cpp:364 #30 0x4030bc02 in ViewportFrame::Reflow (this=0x81cbe90, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe948, aReflowState=@0xbfffe894, aStatus=@0xbfffe890) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsViewportFrame.cpp:436 #31 0x402e8b0f in nsHTMLReflowCommand::Dispatch (this=0x81c8f38, aPresContext=@0x81979f0, aDesiredSize=@0xbfffe948, aMaxSize=@0xbfffe938, aRendContext=@0x81c8f68) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsHTMLReflowCommand.cpp:164 #32 0x402fe474 in PresShell::ProcessReflowCommands (this=0x81d9828) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsPresShell.cpp:1116 #33 0x402fcc47 in PresShell::ExitReflowLock (this=0x81d9828) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsPresShell.cpp:595 #34 0x402feee7 in PresShell::ContentChanged (this=0x81d9828, aDocument=0x81a9698, aContent=0x81de5cc, aSubContent=0x0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsPresShell.cpp:1369 #35 0x4029c9e0 in nsDocument::ContentChanged (this=0x81a9698, aContent=0x81de5cc, aSubContent=0x0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/base/src/nsDocument.cpp:1150 #36 0x4029769b in nsGenericDOMDataNode::ReplaceData (this=0x81de5d8, aOffset=0, aCount=33, aData=@0xbfffea54) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/base/src/nsGenericDOMDataNode.cpp:344 #37 0x40297456 in nsGenericDOMDataNode::DeleteData (this=0x81de5d8, aOffset=0, aCount=34) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/base/src/nsGenericDOMDataNode.cpp:297 #38 0x402c7c52 in nsTextNode::DeleteData (this=0x81de5c0, aOffset=0, aCount=34) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/base/src/nsTextNode.cpp:52 #39 0x40ded5c6 in ?? () #40 0x40dec31b in ?? () #41 0x40def5d3 in ?? () #42 0x40dec31b in ?? () #43 0x40dec31b in ?? () #44 0x413b0598 in ?? () #45 0x413b1927 in ?? () #46 0x413b0fa6 in ?? () #47 0x40de5c61 in ?? () #48 0x40de6490 in ?? () #49 0x40de9685 in ?? () #50 0x40dea477 in ?? () #51 0x402c90c6 in nsEventListenerManager::HandleEvent (this=0x81f60a0, aPresContext=@0x81979f0, aEvent=0xbffff118, aDOMEvent=0xbfffede0, aEventStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/events/src/nsEventListenerManager.cpp:379 #52 0x4029d944 in nsDocument::HandleDOMEvent (this=0x81a9698, aPresContext=@0x81979f0, aEvent=0xbffff118, aDOMEvent=0xbfffede0, aFlags=1, aEventStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/base/src/nsDocument.cpp:1668 #53 0x4033f5fd in nsHTMLHtmlElement::HandleDOMEvent (this=0x8197428, aPresContext=@0x81979f0, aEvent=0xbffff118, aDOMEvent=0x0, aFlags=1, aEventStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/content/src/nsHTMLHtmlElement.cpp:173 #54 0x402ffca2 in PresShell::HandleEvent (this=0x81d9828, aView=0x81f17b8, aEvent=0xbffff118, aEventStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/layout/html/base/src/nsPresShell.cpp:1728 #55 0x4064bcf8 in nsView::HandleEvent (this=0x81f17b8, event=0xbffff118, aEventFlags=8, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsView.cpp:824 #56 0x4064bc71 in nsView::HandleEvent (this=0x81f0610, event=0xbffff118, aEventFlags=8, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsView.cpp:806 #57 0x4064bc71 in nsView::HandleEvent (this=0x81fbbb8, event=0xbffff118, aEventFlags=8, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsView.cpp:806 #58 0x4064e56e in nsScrollingView::HandleEvent (this=0x81fbbb8, aEvent=0xbffff118, aEventFlags=8, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsScrollingView.cpp:812 #59 0x4064bc71 in nsView::HandleEvent (this=0x81d9d38, event=0xbffff118, aEventFlags=28, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsView.cpp:806 #60 0x4065216c in nsViewManager::DispatchEvent (this=0x81d9778, aEvent=0xbffff118, aStatus=@0xbffff0a8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsViewManager.cpp:1230 #61 0x40649a0c in HandleEvent (aEvent=0xbffff118) at /usr/people/kin/builds/raptor.02_16_99/mozilla/view/src/nsView.cpp:63 #62 0x4005f3fa in nsWidget::DispatchEvent (this=0x81f0690, event=0xbffff118, aStatus=@0xbffff0e4) at /usr/people/kin/builds/raptor.02_16_99/mozilla/widget/src/gtk/nsWidget.cpp:775 #63 0x4005f2d8 in nsWidget::DispatchWindowEvent (this=0x81f0690, event=0xbffff118) at /usr/people/kin/builds/raptor.02_16_99/mozilla/widget/src/gtk/nsWidget.cpp:735 #64 0x40060350 in nsWindow::OnKey (this=0x81f0690, aEvent=@0xbffff118) at /usr/people/kin/builds/raptor.02_16_99/mozilla/widget/src/gtk/nsWindow.cpp:417 #65 0x4005d193 in handle_key_press_event (w=0x81f0868, event=0x8189248, p=0x81f0690) at /usr/people/kin/builds/raptor.02_16_99/mozilla/widget/src/gtk/nsGtkEventHandler.cpp:742 #66 0x40b1669d in gtk_marshal_BOOL__POINTER (object=0x81f0868, func=0x4005d148 <handle_key_press_event(_GtkWidget *, _GdkEventKey *, void *)>, func_data=0x81f0690, args=0xbffff204) at gtkmarshal.c:32 #67 0x40adbf8a in gtk_handlers_run (handlers=0x8178230, signal=0xbffff1c0, object=0x81f0868, params=0xbffff204, after=0) at gtksignal.c:1877 #68 0x40adb573 in gtk_signal_real_emit (object=0x81f0868, signal_id=26, params=0xbffff204) at gtksignal.c:1445 #69 0x40ad989c in gtk_signal_emit (object=0x81f0868, signal_id=26) at gtksignal.c:528 #70 0x40b0de38 in gtk_widget_event (widget=0x81f0868, event=0x8189248) at gtkwidget.c:2745 #71 0x40b15092 in gtk_window_key_press_event (widget=0x80ede98, event=0x8189248) at gtkwindow.c:1017 #72 0x40b1669d in gtk_marshal_BOOL__POINTER (object=0x80ede98, func=0x40b14f8c <gtk_window_key_press_event>, func_data=0x0, args=0xbffff560) at gtkmarshal.c:32 #73 0x40adb5aa in gtk_signal_real_emit (object=0x80ede98, signal_id=26, params=0xbffff560) at gtksignal.c:1460 #74 0x40ad989c in gtk_signal_emit (object=0x80ede98, signal_id=26) at gtksignal.c:528 #75 0x40b0de38 in gtk_widget_event (widget=0x80ede98, event=0x8189248) at gtkwidget.c:2745 #76 0x40aaf089 in gtk_propagate_event (widget=0x81f0868, event=0x8189248) at gtkmain.c:1262 #77 0x40aae436 in gtk_main_do_event (event=0x8189248) at gtkmain.c:734 #78 0x40b52b6e in gdk_event_dispatch (source_data=0x0, current_time=0xbffff8e0, user_data=0x0) at gdkevents.c:2073 #79 0x40b7ec77 in g_main_dispatch (current_time=0xbffff8e0) at gmain.c:640 #80 0x40b7f203 in g_main_iterate (block=1, dispatch=1) at gmain.c:847 #81 0x40b7f385 in g_main_run (loop=0x8188e98) at gmain.c:905 #82 0x40aadeb3 in gtk_main () at gtkmain.c:457 #83 0x40054cb4 in nsAppShell::Run (this=0x809c4f0) at /usr/people/kin/builds/raptor.02_16_99/mozilla/widget/src/gtk/nsAppShell.cpp:145 #84 0x80537d2 in nsNativeViewerApp::Run (this=0x8098ef8) at /usr/people/kin/builds/raptor.02_16_99/mozilla/webshell/tests/viewer/nsGTKMain.cpp:42 #85 0x8053a36 in main (argc=1, argv=0xbffff9a4) at /usr/people/kin/builds/raptor.02_16_99/mozilla/webshell/tests/viewer/nsGTKMain.cpp:97 (gdb)

As of this afternoon's build, you don't have to select a line or delete it, just click somewhere to set the collapsed selection and hit return. I filed bug 3169 on it, will mark that bug as a dup of this one.

*** Bug 3169 has been marked as a duplicate of this bug. ***

The assertion turns out to be bogus; I removed it and fixed this special case of removal (the :first-letter style is what triggered the assertion).

Using 3/26 build on Win 95, Win NT, Win 98, Mac8.5 and Linux, followed procedure and there were no crashes. Verifying bug fixed.