1178382 - Checkerboarding scrolling through a <select size=n> list box

Status: RESOLVED FIXED

(Core :: Panning and Zooming, defect)

Description

[Kyle Fung]

Steps to reproduce:
Go to https://bugzilla.mozilla.org/enter_bug.cgi?product=Core
Scroll the box under "Component" up and down

This causes the box to show checkerboard yellow without any text

Comment 1

[Markus Stange [:mstange]]

Attachment: testcase

Comment 2

[Markus Stange [:mstange]]

Attachment: MozReview Request: Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

forms.css sets overflow: -moz-hidden-unscrollable on all select elements.
ApplyOverflowClipping in nsFrame.cpp applies overflow clips that are not managed by scroll frames.
nsCSSFrameConstructor::ConstructSelectFrame creates an nsListControlFrame for listbox select elements.
nsListControlFrame is an nsHTMLScrollFrame.
As a result, the clip as applied twice - once by the nsHTMLScrollFrame, and then again by ApplyOverflowClipping.
Adding an exception for nsListControlFrame to ShouldApplyOverflowClipping gets rid of the double clip.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8629499 [details]
MozReview Request: Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

https://reviewboard.mozilla.org/r/12621/#review11089

Ship It!

Comment 4

[Markus Stange [:mstange]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/0642a5722c59

Comment 5

[Phil Ringnalda (:philor)]

Backed out in https://hg.mozilla.org/integration/mozilla-inbound/rev/459cf9e67ded for OS X reftest failures like http://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=http://ftp.mozilla.org/pub/mozilla.org/firefox/tinderbox-builds/mozilla-inbound-macosx64-debug/1435968762/mozilla-inbound_yosemite-debug_test-reftest-bm107-tests1-macosx-build592.txt.gz&only_show_unexpected=1

Comment 6

[Markus Stange [:mstange]]

Comment on attachment 8629499 [details]
MozReview Request: Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

forms.css sets overflow: -moz-hidden-unscrollable on all select elements.
ApplyOverflowClipping in nsFrame.cpp applies overflow clips that are not managed by scroll frames.
nsCSSFrameConstructor::ConstructSelectFrame creates an nsListControlFrame for listbox select elements.
nsListControlFrame is an nsHTMLScrollFrame.
As a result, the clip as applied twice - once by the nsHTMLScrollFrame, and then again by ApplyOverflowClipping.
Adding an exception for nsListControlFrame to ShouldApplyOverflowClipping gets rid of the double clip.
But we still need to apply the clip when calculating the frame's visual overflow rect, so we add the
list box frame type to the list of special-cased frames in UnionBorderBoxes.

Comment 7

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 8629499 [details]
MozReview Request: Bug 1178382 - Ignore overflow: -moz-hidden-unscrollable on <select size=n> listboxes.

https://reviewboard.mozilla.org/r/12621/#review11267

Ship It!

Comment 8

[Markus Stange [:mstange]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=5473a855341a

Comment 9

[Markus Stange [:mstange]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/0c395b7feaba

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/0c395b7feaba