Canvas is not reset when setting canvas.width

1) Open this page : http://codingwithattitude.net/gml/gml-drawer.html and draw lines on the black canvas (this uses regular mousedown, mousemove and mouseup events)

2) Click on the "clear" action.

Expected result:
The canvas should be reset by setting its width to the original width

Observed result:
Nothing. Subsequently drawing on the surface adds a black square covering the old drawing under the new drawing.

Platform:
WebKit-r64451 nightly on Windows XP

[Matthew Delaney]

Created attachment 63409 [details]
Patch

[Darin Adler]

Comment on attachment 63409 [details]
Patch

Bug fixes need a test case. Could you make a test for this one please?

[Darin Adler]

Comment on attachment 63409 [details]
Patch

review- due to lack of regression test

Fix itself looks good, although I might move the initialization of hadImageBuffer up even higher.

[Matthew Delaney]

Created attachment 63534 [details]
Patch

[Darin Adler]

Comment on attachment 63534 [details]
Patch

> -    bool ok;
> +    bool ok, hadImageBuffer = hasCreatedImageBuffer();

The two booleans should be defined on separate lines. We don't do two on one line like this in WebKit.

> Index: LayoutTests/fast/repaint/setWidthResetAfterForcedRender.html

While this does involve "repainting", I think this is a canvas test and should be in "fast/canvas".

Patch is OK as is, so review+ but I'm not setting commit-queue on this so you have a chance to decide whether to make some additional refinements before landing this.

[Matthew Delaney]

Created attachment 63611 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 63611 [details]
Patch

Rejecting patch 63611 from commit-queue.

Failed to run "[u'git', u'svn', u'dcommit']" exit_code: 1
Last 500 characters of output:
e/ChangeLog
	M	WebCore/html/HTMLCanvasElement.cpp
A repository hook failed: MERGE request failed on '/repository/webkit/trunk': Commit blocked by pre-commit hook (exit code 1) with output:

    The following files contain tab characters:

        trunk/LayoutTests/fast/canvas/setWidthResetAfterForcedRender.html

    Please use spaces instead to indent.
    If you must commit a file with tabs, use svn propset to set the "allow-tabs" property.
 at /usr/local/git/libexec/git-core/git-svn line 572


Full output: http://queues.webkit.org/results/3576985

[Matthew Delaney]

Created attachment 64035 [details]
Patch

[Matthew Delaney]

Hopefully this one makes the commit bot happy :-)

[Kenneth Rohde Christiansen]

Comment on attachment 64035 [details]
Patch

WebCore/ChangeLog:10
 +          hasCreatedImageBuffer up *before* the call to setSurface since setSurface
I guess this comment would be nice in the code as well.

[WebKit Commit Bot]

Comment on attachment 64035 [details]
Patch

Clearing flags on attachment: 64035

Committed r65367: <http://trac.webkit.org/changeset/65367>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.