User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/116.0

Steps to reproduce:

Drawing on a canvas with lineTo() sometimes renders a weird dotted line with unrelated coordinates.

I'm attaching the HTML file with a minimal version that I could come up with; here's a codepen version with a similar code: https://codepen.io/berekuk/pen/OJarJeY?editors=1010

Platform: Firefox Developer Edition, macOS M1 Pro (I'm not sure if this problem is macOS-specific).

Note: this happens only on some paths and is extremely sensitive to coordinate changes; if I slightly change any number in a sequence, the line often (but not always) disappears.

Actual results:

The requested line is drawn, but an extra dotted line going in an unrelated direction appears.

Expected results:

No dotted line should be drawn.

Can repro on Windows11x64 by enabling gpu-canvas. Can not repro if I enable gpu-canvas and disable aa-stroke.

Regression range: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=38ad87bc6f42df650e19616ba8bf27b5d5a68afe&tochange=7e2df6f0d1fd4ddafbab78ee29b418a966d27569

suspect: bug 1803604

:lsalzman, since you are the author of the regressor, bug 1803604, could you take a look? Also, could you set the severity field?

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Set release status flags based on info from the regressing bug 1803604

:lsalzman can you help with the severity/priority on this one?

The severity field is not set for this bug.
:lsalzman, could you have a look please?

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I think this might get fixed by bug 1841020

Looks fixed to me.