"""See the attached test case. It's a <canvas> with minimal events handling, just changing the cursor shape depending on the event and its location. It's a subset of one of my WebApps heavily using <canvas>. Instructions & expectations are included in the test page.""" Corresponding chromium bug is http://crbug.com/37750 .
Created attachment 50405 [details] Repro.
There seem to be two problems here: 1) Cursor doesn't change immediately on mousedown event. This is not specific to canvas - The same happens with an <img>, for example. You need to move the mouse a little for the cursor to change. 2) One you start moving the mouse, the cursor changes to text selection one. Which it shouldn't, because canvas is not text! We will probably need to track these in separate bugs, because these are different area of code.
The cursor bug is bug 14344, so I'll retitle this to ap's #2. The test case is quite useful for demonstrating the problem, but it is not a layout test.
I am not able to reproduce this via doing mouse down while trying to drag on 'red' container, while as for on text-selection, the cursor changing to I-Beam and not respecting explicitly set cursor, I just fixed it in this commit: https://github.com/WebKit/WebKit/commit/15042015b0c8ed72c5d6e8e226e117dcc8041d48