1794956 - transferToimageBitmap should not reset the context

Status: VERIFIED FIXED

(Core :: Graphics: Canvas2D, defect, P1)

Description

[Kaiido]

Attachment: test-case.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:105.0) Gecko/20100101 Firefox/105.0

Steps to reproduce:

https://jsfiddle.net/am16Lhk4/

1. Set some properties to an OffscreenCanvas's 2D context, like fillStyle, or changing its CTM.
2. Call the OffscreenCanvas's transferToImageBitmap() method.
3. Perform new drawings without resetting the properties set at step 1.

Actual results:

All the properties set at step 1 where reset to their default.

Expected results:

Per specs only the bitmap buffer is supposed to get cleared by this operation, the context's properties are supposed to be preserved.

Comment 1

[Ashley Hale [:ahale]]

Triage - assigning S2 initially. I will see if mozregression reveals a working version.

Comment 2

[Ashley Hale [:ahale]]

Attachment: Screenshot 2022-10-12 at 22-10-57 https __bug1794956.bmoattachments.org.png

Comment 3

[Ashley Hale [:ahale]]

To see if this is a regression I did mozregression using the provided test page, this feature used to be broken in a worse way as far back as FF95 (the actual result boxes are blank). As of FF104 it looks like the result in comment #2, which is broken in the way described in comment #1.

NeedInfo - Any additional info we will need to be able to address this bug?

Comment 4

[Kelsey Gilbert [:jgilbert]]

We guessed wrong here, and we should not be resetting here:
https://searchfox.org/mozilla-central/rev/76ccfc801e6b736c844cde3fddeab7a748fc8515/dom/canvas/OffscreenCanvas.cpp#267-271

    // FIXME(aosmond): The spec is unclear about the state of the canvas after
    // clearing. Does it expect to preserve the WebGL state, other than the
    // buffer state? Once we have clarity, we should ensure we clear the WebGL
    // canvas as desired.
    mCurrentContext->Reset();

Comment 5

[Kelsey Gilbert [:jgilbert]]

Attachment: Bug 1794956 - TransferToImageBitmap should reset bitmap but not state.

s/Reset/ResetBitmap/ and implement for WebGL and WebGPU.

Comment 6

[Kelsey Gilbert [:jgilbert]]

That fixes the testcase behavior.
We need (more? fixed?) tests for this though, so let me add those here.

Comment 7

[Kelsey Gilbert [:jgilbert]]

Attachment: Bug 1794956 - Repair and enable test_offscreencanvas_toimagebitmap.html.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3abcf6ccf88a
TransferToImageBitmap should reset bitmap but not state. r=gfx-reviewers,lsalzman
https://hg.mozilla.org/integration/autoland/rev/7b3067b086e6
Repair and enable test_offscreencanvas_toimagebitmap.html. r=gfx-reviewers,lsalzman

Comment 9

[Iulian Moraru]

Backed out for causing wpt failures on offscreencanvas.transfer.to.imagebitmap.html.

This fails on multiple platforms.
Push where the failures appeared
Push with failures

Failure log

Backout link

[task 2022-10-15T15:38:15.430Z] 15:38:15     INFO - TEST-START | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html
[task 2022-10-15T15:38:15.434Z] 15:38:15     INFO - Closing window a451e800-7db1-451d-869b-2997a2056bd1
[task 2022-10-15T15:38:15.509Z] 15:38:15     INFO - 
[task 2022-10-15T15:38:15.509Z] 15:38:15     INFO - TEST-PASS | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html | Test that transferToImageBitmap returns an ImageBitmap with correct width and height 
[task 2022-10-15T15:38:15.510Z] 15:38:15     INFO - TEST-PASS | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html | Test that transferToImageBitmap returns an ImageBitmap with correct color 
[task 2022-10-15T15:38:15.510Z] 15:38:15     INFO - TEST-UNEXPECTED-PASS | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html | Test that transferToImageBitmap won't change context's property - expected FAIL
[task 2022-10-15T15:38:15.510Z] 15:38:15     INFO - TEST-INFO | expected FAIL
[task 2022-10-15T15:38:15.511Z] 15:38:15     INFO - 
[task 2022-10-15T15:38:15.511Z] 15:38:15     INFO - TEST-UNEXPECTED-PASS | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html | Test that transferToImageBitmap preserves transform - expected FAIL
[task 2022-10-15T15:38:15.511Z] 15:38:15     INFO - TEST-INFO | expected FAIL
[task 2022-10-15T15:38:15.512Z] 15:38:15     INFO - ..
[task 2022-10-15T15:38:15.512Z] 15:38:15     INFO - TEST-OK | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.html | took 80ms
[task 2022-10-15T15:38:15.514Z] 15:38:15     INFO - PID 2188 | 1665848295510	Marionette	INFO	Stopped listening on port 59578
[task 2022-10-15T15:38:15.811Z] 15:38:15     INFO - PID 2188 | [2022-10-15T15:38:15Z ERROR xulstore::persist] removeDocument error: unavailable
[task 2022-10-15T15:38:15.841Z] 15:38:15     INFO - Browser exited with return code 0
[task 2022-10-15T15:38:15.844Z] 15:38:15     INFO - Closing logging queue
[task 2022-10-15T15:38:15.844Z] 15:38:15     INFO - queue closed
[task 2022-10-15T15:38:16.014Z] 15:38:16     INFO - Application command: /opt/worker/tasks/task_166584702349171/build/application/Firefox Nightly.app/Contents/MacOS/firefox --marionette about:blank -foreground -profile /var/folders/s_/lbx5y22n31l0w_7s1y123mzw000014/T/tmp21rji15v
[task 2022-10-15T15:38:16.023Z] 15:38:16     INFO - PID 2246 | 1665848202123	Marionette	INFO	Marionette enabled
[task 2022-10-15T15:38:16.023Z] 15:38:16     INFO - PID 2246 | 1665848202148	Marionette	INFO	Listening on port 59820
[task 2022-10-15T15:38:16.024Z] 15:38:16     INFO - PID 2246 | console.warn: SearchSettings: "get: No settings file exists, new profile?" (new NotFoundError("Could not open the file at /var/folders/s_/lbx5y22n31l0w_7s1y123mzw000014/T/tmpb5qrv6yh/search.json.mozlz4", (void 0)))
[task 2022-10-15T15:38:16.025Z] 15:38:16     INFO - PID 2246 | 2022-10-15 15:37:12.090 firefox[2246:55147] Persistent UI failed to open file file:///Users/cltbld/Library/Saved%20Application%20State/org.mozilla.nightly.savedState/window_1.data: No such file or directory (2)
[task 2022-10-15T15:38:16.025Z] 15:38:16     INFO - Starting runner
[task 2022-10-15T15:38:16.628Z] 15:38:16     INFO - TEST-START | /html/canvas/offscreen/manual/the-offscreen-canvas/offscreencanvas.transfer.to.imagebitmap.nocrash.html
[task 2022-10-15T15:38:16.720Z] 15:38:16     INFO - .

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/78a3979d12d7
TransferToImageBitmap should reset bitmap but not state. r=gfx-reviewers,lsalzman
https://hg.mozilla.org/integration/autoland/rev/1324acbcc0e2
Repair and enable test_offscreencanvas_toimagebitmap.html. r=gfx-reviewers,lsalzman

Comment 11

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/78a3979d12d7
https://hg.mozilla.org/mozilla-central/rev/1324acbcc0e2

Comment 12

[Ardelean Oana, Desktop Test Engineering [:oardelean]]

I managed to reproduce this issue on a 2022-10-12 Nightly build on macOS 12 using the testcase attached in Comment 0. Verified as fixed on Firefox 107.0b4(build ID: 20221023190001), Nightly 108.0a1(build ID: 20221023100414) on macOS 12, Windows 10, Ubuntu 22.