566606 - nsHTMLCanvasFrame::GetCanvasSize() does conditional jump based on uninitialized value

Status: RESOLVED DUPLICATE of bug 566603

(Core :: Layout: Images, Video, and HTML Frames, defect)

Description

[Benoit Jacob [:bjacob] (mostly away)]

Attachment: initialize value in GetCanvasSize

See attached patch. This is a fix for a "conditional jump based on uninitialized value" error reported by valgrind as follows:

Canvas 3D: creating PBuffer...
Canvas 3D: can't get a native PBuffer, trying OSMesa...
Canvas 3D: ready
==8679== Thread 1:
==8679== Conditional jump or move depends on uninitialised value(s)
==8679==    at 0x59F3981: nsHTMLCanvasFrame::GetCanvasSize()
(nsHTMLCanvasFrame.cpp:123)
==8679==    by 0x59F3B37: nsHTMLCanvasFrame::ComputeSize(nsIRenderingContext*,
nsSize, int, nsSize, nsSize, nsSize, int) (nsHTMLCanvasFrame.cpp:164)
==8679==    by 0x59FDEB6: nsHTMLReflowState::InitConstraints(nsPresContext*,
int, int, nsMargin const*, nsMargin const*) (nsHTMLReflowState.cpp:1847)
==8679==    by 0x59FA162: nsHTMLReflowState::Init(nsPresContext*, int, int,
nsMargin const*, nsMargin const*) (nsHTMLReflowState.cpp:283)
==8679==    by 0x59F9DF1: nsHTMLReflowState::nsHTMLReflowState(nsPresContext*,
nsHTMLReflowState const&, nsIFrame*, nsSize const&, int, int, int)
(nsHTMLReflowState.cpp:176)
==8679==    by 0x5A134C9: nsLineLayout::ReflowFrame(nsIFrame*, unsigned int&,
nsHTMLReflowMetrics*, int&) (nsLineLayout.cpp:772)
==8679==    by 0x599E986: nsBlockFrame::ReflowInlineFrame(nsBlockReflowState&,
nsLineLayout&, nsLineList_iterator, nsIFrame*, LineReflowStatus*)
(nsBlockFrame.cpp:3716)
==8679==    by 0x599DEAD:
nsBlockFrame::DoReflowInlineFrames(nsBlockReflowState&, nsLineLayout&,
nsLineList_iterator, nsFlowAreaRect&, int&, nsFloatManager::SavedState*, int*,
LineReflowStatus*, int) (nsBlockFrame.cpp:3511)
==8679==    by 0x599D93B: nsBlockFrame::ReflowInlineFrames(nsBlockReflowState&,
nsLineList_iterator, int*) (nsBlockFrame.cpp:3365)
==8679==    by 0x599AD20: nsBlockFrame::ReflowLine(nsBlockReflowState&,
nsLineList_iterator, int*) (nsBlockFrame.cpp:2461)
==8679==    by 0x5998AC1: nsBlockFrame::ReflowDirtyLines(nsBlockReflowState&)
(nsBlockFrame.cpp:1907)
==8679==    by 0x5995C61: nsBlockFrame::Reflow(nsPresContext*,
nsHTMLReflowMetrics&, nsHTMLReflowState const&, unsigned int&)
(nsBlockFrame.cpp:1009)

See bug 525538

Comment 1

[Boris Zbarsky [:bzbarsky]]

See bug 566603?

Comment 3

[Benoit Jacob [:bjacob] (mostly away)]

Yes, duplicate, thanks.

Comment 4

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

I think I prefer the patch I came up with (and filed a whole 20 minutes earlier), since it removes more code.

Comment 5

[Benoit Jacob [:bjacob] (mostly away)]

David: sure! Being new here I just went for the smallest possible patch. But your patch is better!