Based on HTML5: The arcTo(x1, y1, x2, y2, radius) method must first ensure there is a subpathp240 for (x1, y1). Then, the behavior depends on the arguments and the last point in the subpath, as described below.
Created attachment 55236 [details] patch put a patch
In the WebKit project we require test cases for bugs being fixed. Can we somehow import this test suite?
(In reply to comment #2) > In the WebKit project we require test cases for bugs being fixed. Can we somehow import this test suite? Philip's test cases was landed: https://bugs.webkit.org/show_bug.cgi?id=20553 , so we can check this bug now. I tested this patch, it fixes canvas/philip/tests/2d.path.arcTo.ensuresubpath.1.html, but unfortunately brake an other test case: canvas/philip/tests/2d.path.arcTo.ensuresubpath.2.html -Passed +Failed assertion: got pixel [255,0,0,255] at (50,25), expected [0,255,0,255]
I will check this bug with the philip test case and make a new patch soon.
Created attachment 57766 [details] patch2 Create a new patch to: 1> enable canvas/philip/tests/2d.path.arcTo.ensuresubpath.1.html 2> changed the code to add moveTo when there is no subpath
Created attachment 57797 [details] patch3 Minor change on comments.
Comment on attachment 57797 [details] patch3 lgtm, r+.
Comment on attachment 57797 [details] patch3 Clearing flags on attachment: 57797 Committed r60664: <http://trac.webkit.org/changeset/60664>
All reviewed patches have been landed. Closing bug.