2161 - [PP] Drag-scrolling a web page crashes Mac Viewer & XPAppViewer

Status: VERIFIED FIXED

(Core Graveyard :: Viewer App, defect, P1)

Description

[Eli Goldberg]

* TITLE/SUMMARY
[PP] Drag-scrolling a web page crashes Mac Viewer & XPAppViewer

* STEPS TO REPRODUCE
0) View any web page, including the default sample page
1) Drag-scroll the page (i.e. go to the bottom of the page's content region, hold
down the mouse button, and drag the mouse pointer downwards.)

* RESULT
 - What happened

Crash. Stack crawl will follow.

 - What was expected

No crash, like on Win32.

* REGRESSION

 - Occurs On
        viewer (1.4.98 build on Mac OS)
        XPAppViewer (1.4.98 build on Mac OS)

 - Doesn't Occur On
        viewer (1.4.98 build on Win NT 4 SP3; functionality not supported)


* CONFIGURATIONS TESTED

- PowerMac 8500/150 (233 Mhz 604e), 64 MB RAM, Mac OS 8.5.1

Comment 1

[Eli Goldberg]

[Viewer app stack crawl.]

 Calling chain using A6/R1 links
  Back chain  ISA  Caller
  00000000    PPC  0BA85E74
  03AF0200    PPC  0BA7D1D8
  03AF01A0    PPC  0BA7CBEC
  03AF0160    PPC  0B754F18  nsMacMessageSink::DispatchMenuCommand(EventRecord&,
long)+004FC
  03AF0080    PPC  0B755328  nsMacMessageSink::DispatchMenuCommand(EventRecord&,
long)+0090C
  03AF0020    PPC  0B75579C  nsMacMessageSink::DispatchMenuCommand(EventRecord&,
long)+00D80
  03AEFFD0    PPC  0B755A30  nsMacMessageSink::DispatchMenuCommand(EventRecord&,
long)+01014
  03AEFF90    PPC  0B754A00  nsMacMessageSink::DispatchOSEvent(EventRecord&,
GrafPort*)+00040
  03AEFF40    PPC  0B752AC4  NS_GetWidgetNativeData(nsISupports*, void**)+0BD14
  03AEFEE0    PPC  0B752C5C  NS_GetWidgetNativeData(nsISupports*, void**)+0BEAC
  03AEFEA0    PPC  0B753134  NS_GetWidgetNativeData(nsISupports*, void**)+0C384
  03AEFE20    PPC  0B742348
  03AEFDC0    PPC  0B7422D0
  03AEFD80    PPC  0B742248
  03AEFD30    PPC  0B50FDDC  NSGetFactory+027FC
PowerPC unmapped memory exception at 0B512BD0 NSGetFactory+055F0

Comment 2

[chris hofmann]

reassign to pierre for load balancing in PP milestone

Comment 3

[Eli Goldberg]

<Note that this bug *does* occur using the 11.4.98 debug build, too.>

Comment 4

[Pierre Saslawsky]

Reassigned to <sfraser>

Comment 5

[Simon Fraser [no longer active]]

This is because nsView::GetViewFor(nsIWidget* aWidget) is being called with a
null widget. The fix is to check for a null widget.

Comment 6

[Eli Goldberg]

Verified fixed in 1.12.98 build.

Specifically, drag scrolling upwards, downwards and horizontally yields the same
behavior as on the Win32 and Linux builds. [aka, rather than crashing the Mac, it
just doesn't work.]

Thanks, Simon!

Comment 7

[leger]

Inserting Milestone info.