1383568 - Unable to scroll properly in vertically with scrollbar on certain page

Status: VERIFIED FIXED

(Core :: Layout, defect)

Description

[Alice0775 White]

Attachment: test page removed all JavaScript

[Tracking Requested - why for this release]: Broken scroll with scrollbar

Reproducible : always

Steps To Reproduce:
1. Maximized window
2. Open https://abema.tv/timetable (It may be available only in the region of Japan)
   Wait to load page
3. Click [x] button if small popup display at center of page
4. Attempt to scroll in vertically with dragging thumb up and down
   And/or Attempt to scroll in vertically with clicking scrollbar empty area and arrow buttons.


Steps To Reproduce:
1. Maximized window
2. Open index.html in attached zip file
3. Attempt to scroll in vertically with dragging thumb up and down.
   And/or Attempt to scroll in vertically with clicking scrollbar empty area and arrow buttons.


Actual Results:
Unable to scroll properly.

Expected Results:
scroll properly.


Regression Window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=3b5eec74e7e5fdd9f3f92df6f68aa981ecb227a8&tochange=bc4c5281f2c23c7d643c6c5580789047c5f0c0ec

Regressed by:
bc4c5281f2c2	Timothy Nikkel — Bug 1379887. Don't clobber the value of mWillBuildScrollableLayer when we are building a display list for event handling. r=mstange

Comment 1

[Gerry Chang [:gchang]]

Track 56+ as new regression. 
Hi :tnikkel,
Can you help shed some light here?

Comment 2

[Timothy Nikkel (:tnikkel)]

I investigated a similar thing in bug 1381708. Because we correctly determine a non-root scrollframe is active we therefore insert a clip for it in the clip chain of the scroll bar items. Somehow that causes a problem, which is odd since it makes the displaylist used for hittesting more like the one used for painting, and since we are painting correctly you'd expect that to be a good thing. I'll continue to investigate, if I don't make progress quick I'll backout the regressing bug since we don't need it on trunk (only for retained display lists which is only on a branch right now).

Comment 3

[Timothy Nikkel (:tnikkel)]

Should be fixed by backout of bug 1379887.

Comment 4

[Alice0775 White]

verified. the problem is fixed in m-i.

Comment 5

[Timothy Nikkel (:tnikkel)]

Alice, could you try this try build and see if you can reproduce this bug?

https://treeherder.mozilla.org/#/jobs?repo=try&revision=9e99298c170f96c96f00baf93075784d5b142ba4

It has the patch from bug 1379887 applied. I wasn't able to reproduce this bug anymore.

Comment 6

[Alice0775 White]

(In reply to Timothy Nikkel (:tnikkel) from comment #5)
> Alice, could you try this try build and see if you can reproduce this bug?
> 
> https://treeherder.mozilla.org/#/
> jobs?repo=try&revision=9e99298c170f96c96f00baf93075784d5b142ba4
> 
> It has the patch from bug 1379887 applied. I wasn't able to reproduce this
> bug anymore.


On the try build, The following problem occurs.
A. Clicking on scroll arrow buttons(top/bottom) do not work.
B. While dragging vertical scroll-thumb, the contents also scroll in horizontally.
C. Sometimes, the thumb becomes undraggable. and Sometimes scroll position position is rewound.
   STR: Repeat dragging thumb to the bottom and release mouse, and dragging to the top and release mouse.