722888 - [multicol] insufficient invalidation after content is removed from beginning of a multicol container

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:
 1. Load attached testcase

EXPECTED RESULTS:
 Yellow div, with only "a" visible in upper-left corner.

ACTUAL RESULTS:
 "9 0 a" is also visible, from initial rendering, until the window is fully invalidated.

NOTE: The rendering seems to depend on the exact text positioning (e.g. if I add/remove a few characters, the bug goes away) -- so it may not reproduce with this testcase on other platforms w/ different fonts.

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

(changed parentElement to parentNode in the testcase's JS, to make it load in older Firefox versions as well)

Comment 2

[Daniel Holbert [:dholbert]]

I can repro in trunk, but not in Firefox 4 --> regression
 Mozilla/5.0 (X11; Linux x86_64; rv:12.0a1) Gecko/20120131 Firefox/12.0a1
 Mozilla/5.0 (X11; Linux x86_64; rv:2.0) Gecko/20100101 Firefox/4.0

Comment 3

[Daniel Holbert [:dholbert]]

This regressed in the last month, actually.
 Last good nightly: 2011-12-26
 First bad nightly: 2011-12-27
 Pushlog:
 http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9f29daaecbcc&tochange=6f4f2e53694b

Looks like a regression from Bug 695222.

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: screenshot ("9 0a" shouldn't be visible)

Comment 5

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #3)
> Looks like a regression from Bug 695222.

Yup -- I confirmed via targeted builds that
   http://hg.mozilla.org/mozilla-central/rev/93b804e5f3f5
is the first cset affected by this bug.

Comment 6

[Daniel Holbert [:dholbert]]

WFM in nightly:
 Mozilla/5.0 (X11; Linux x86_64; rv:23.0) Gecko/20130507 Firefox/23.0

Comment 7

[Daniel Holbert [:dholbert]]

Fix range:
{
Last bad nightly: 2012-09-28
First good nightly: 2012-09-29

Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=895f66c4eada&tochange=c09a0c022b2e
}

That includes DLBI, which is almost certainly what fixed this.

Updating resolution to FIXED by that.

Comment 8

[Daniel Holbert [:dholbert]]

Landed a reftest made from this bug's attached testcase:
  https://hg.mozilla.org/integration/mozilla-inbound/rev/5a5e13148f9d

(w/ earlier try server sanity check: https://tbpl.mozilla.org/?tree=Try&rev=4faba653fb37 )

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/5a5e13148f9d