474817 - graphical corruption between entries in combobox, with margin-top: 0.5px

Status: RESOLVED DUPLICATE of bug 472769

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STEPS TO REPRODUCE:
 1. Click combobox in attached testcase.
 2. Move cursor up & down across the entries of the combobox.

ACTUAL RESULTS: There's a 1px-tall line of corruption (sometimes a shade of gray, sometimes white & black checkered) between the top few entries in the combobox.  (screenshot coming up)

EXPECTED RESULTS: No corruption.

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20090122 Minefield/3.2a1pre

OS: Ubuntu 8.10 and 9.04 alpha

Note: I first noticed this bug in the dropdown menus on Bugzilla's "add attachment" page. I can reproduce it reliably in all three menus at the URL given  ("select from list" menu, "review" menu, and "set the bug status to" menu)

Comment 1

[Daniel Holbert [:dholbert]]

Attachment: testcase 2: uses background, to force non-shiny widget

This testcase uses a lightblue background to force a "firefox classic" (non-OS-themed) widget.  I see the bug in this testcase as well, using the same nightly as before.

Comment 2

[Daniel Holbert [:dholbert]]

I can't reproduce the bug in Firefox 3:
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.5) Gecko/2008121711 Ubuntu/9.04 (jaunty) Firefox/3.0.5

Hence, this is a regression WRT Firefox 3.

Comment 3

[Daniel Holbert [:dholbert]]

Both testcases regressed between these two nightlies:

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20090107 Minefield/3.2a1pre
Built from http://hg.mozilla.org/mozilla-central/rev/670a3b50dfe0

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20090108 Minefield/3.2a1pre
Built from http://hg.mozilla.org/mozilla-central/rev/28488df9e75e

Comment 4

[Daniel Holbert [:dholbert]]

Pushlog for regression range:
http://hg.mozilla.org/mozilla-central/pushloghtml?startdate=2009-01-07+00%3A32%3A00&enddate=2009-01-08+00%3A51%3A00

I'm not sure what's suspicious there... 670a3b50dfe0 has the most relevant checkin-comment, but that's the same revision that the working nightly was built from, so it should be innocent.

Comment 5

[Daniel Holbert [:dholbert]]

I can reproduce on Windows, too:
Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2a1pre) Gecko/20090121 Minefield/3.2a1pre

I can't reproduce on latest-1.9.1, though, so the guilty patch hasn't landed there yet.
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b3pre) Gecko/20090122 Shiretoko/3.1b3pre

Comment 6

[Daniel Holbert [:dholbert]]

Attachment: screenshot of bug on Windows

Comment 7

[Daniel Holbert [:dholbert]]

I suspect Bug 456219 ( http://hg.mozilla.org/mozilla-central/rev/5041ce453104 ) -- I'm testing out that theory with a custom build.

Comment 8

[Daniel Holbert [:dholbert]]

Ah -- looking at the bugs blocking that one, it looks like this is a dupe of bug 474208.

Comment 9

[Daniel Holbert [:dholbert]]

(OS / Platform --> All/All per comment 5 )

Comment 10

[Daniel Holbert [:dholbert]]

oops, meant to dupe to bug 472769.  (those two bugs seem related, but this one's testcase is more like the one on bug 472769.)