1517976 - Test for the "first paint" case of bug 1509575

Status: RESOLVED FIXED

(Core :: Panning and Zooming, enhancement)

Comment 1

[Jan Henning [:JanH]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=e3d1d3f851c0bcdb8122b6b84a290c1d42d79b37

Comment 2

[Jan Henning [:JanH]]

Attachment: Bug 1517976 - Test that resetting WindowUtils.isFirstPaint doesn't clobber APZ scroll position. r?botond

We need to setup a case where the visual viewport is smaller than the layout
viewport. Faking a pinch zoom through touch events is imprecise, whereas calling
windowUtils.setResolutionAndScaleTo(value > 1) to simulate the equivalent
effect of a pinch-zoom on the page led to the subsequent scroll attempt failing
quite often even after calling waitForApzFlushedRepaints().

So instead, we set up a very wide layout viewport through the meta viewport tag,
which on Desktop means additionally enabling the dom.meta-viewport.enabled pref.

Comment 3

[Jan Henning [:JanH]]

(In reply to Jan Henning [:JanH] from comment #1)
> https://treeherder.mozilla.org/#/
> jobs?repo=try&revision=e3d1d3f851c0bcdb8122b6b84a290c1d42d79b37

Great, the original push is restricted only to that particular test paths, but the retriggers totally ignore that and run something completely different...
So the test isn't fundamentally broken anywhere, but that Try push is totally useless with regards to possible intermittent failures.

Comment 4

[Botond Ballo [:botond]]

This depends on "Part 7: Generally enable Visual Viewport for Mochitests. r?botond" from bug 1498812.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0355f47af6ce
Test that resetting WindowUtils.isFirstPaint doesn't clobber APZ scroll position. r=botond

Comment 6

[Dorel Luca [:dluca]]

Backed out changeset 0355f47af6ce (bug 1517976) for mochitest failures in gfx/layers/apz/test/mochitest/test_group_touchevents-4.html. CLOSED TREE

Log:
https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=221428128&repo=autoland&lineNumber=6588

Push with failures:
https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=0355f47af6ceab050018e9c27fc9d9c4bb944662

Backout:
https://hg.mozilla.org/integration/autoland/rev/80aa2eb75893fce84db53d7ab19df29fafe37666

Comment 7

[Botond Ballo [:botond]]

helper_bug1509575.html | visual viewport did scroll - got 18, expected 100

I wonder if perhaps the test is running in a window that sufficiently wide that 2000px of horizontal content is not enough to give it a 100px scroll range.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/81378c45a359
Test that resetting WindowUtils.isFirstPaint doesn't clobber APZ scroll position. r=botond

Comment 9

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/81378c45a359