Bug 41420 – Canvas: arc() with startAngle == endAngle shouldn't add to the path

• Status: RESOLVED
• Resolution: FIXED
• Component: WebCore Misc.

[Andreas Kling]

Quoth HTML5:
"Zero-length line segments must be pruned before stroking a path. Empty subpaths must be ignored."

This would fix one in-tree test:
* canvas/philip/tests/2d.path.stroke.prune.arc.html

Spec link:
http://www.whatwg.org/specs/web-apps/current-work/#dom-context-2d-stroke

[Andreas Kling]

Created attachment 60131 [details]
Proposed patch

[WebKit Commit Bot]

Comment on attachment 60131 [details]
Proposed patch

Rejecting patch 60131 from commit-queue.

Failed to run "['WebKitTools/Scripts/run-webkit-tests', '--no-launch-safari', '--exit-after-n-failures=1', '--ignore-tests', 'compositing', '--quiet']" exit_code: 1
Last 500 characters of output:
iling Java tests
make: Nothing to be done for `default'.
Running tests from /Users/eseidel/Projects/CommitQueue/LayoutTests
Skipped list contained 'compositing/iframes/composited-iframe.html', but no file of that name could be found
Testing 19237 test cases.
canvas/philip/tests/2d.path.stroke.prune.arc.html -> failed

Exiting early after 1 failures. 551 tests run.
31.37s total testing time

550 test cases (99%) succeeded
1 test case (<1%) had incorrect layout
1 test case (<1%) had stderr output

Full output: http://webkit-commit-queue.appspot.com/results/3354269

[Andreas Kling]

Created attachment 60139 [details]
Proposed patch v2

Only unskip test on Qt, test also uses arcTo() which isn't up-to-spec on Mac I guess.
Unfortunately I can't verify that since I don't have a Mac dev env handy.

The missing logic as implemented in Qt's Path::addArcTo():

FloatPoint p0(m_path.currentPosition());
if ((p1.x() == p0.x() && p1.y() == p0.y()) || (p1.x() == p2.x() && p1.y() == p2.y()) || radius == 0.f) {
    m_path.lineTo(p1);
    return;
}

[Eric Seidel (no email)]

Comment on attachment 60131 [details]
Proposed patch

Cleared Darin Adler's review+ from obsolete attachment 60131 [details] so that this bug does not appear in http://webkit.org/pending-commit.

[WebKit Commit Bot]

Comment on attachment 60139 [details]
Proposed patch v2

Clearing flags on attachment: 60139

Committed r63073: <http://trac.webkit.org/changeset/63073>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.