526913 - Artifacts when deselecting table-cells, with table located at fractional px-offset

Status: NEW

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STEPS TO REPRODUCE:
 1. Load URL (or attached tesctase)
 2. Holding your "Ctrl" key down, click-and-drag from the bottom bug summary to the top bug summary
     --> Those table cells should all be selected (outlined) now.
 3. Holding "Ctrl" again, click the lowest cell to deselect it.  Repeat for the next cell up, and the next, moving progressively upwards.

ACTUAL RESULTS:
 Tiny highlight-lines are left between all or most of the deselected cells.

NOTE: If I un-focus the Firefox window, the highlight lines go away.

NOTE: If I deselect the cells in the opposite order (starting at the top and moving downwards), then I don't get the bug.

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.3a1pre) Gecko/20091105 Minefield/3.7a1pre

Comment 1

[Daniel Holbert [:dholbert]]

I can reproduce this in Firefox 3.0 as well.  Table-cell-selection/deselection works a little differently in 3.0, so I haven't got exact steps to reproduce this there -- however, after ~30 seconds of holding ctrl and clicking-and-dragging over the testcase's cells, I saw this bug's artifacts turn up at least a few times.

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.16pre) Gecko/2009110204 GranParadiso/3.0.16pre

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screenshot of artifacts

Here's a screenshot of the artifacts in a mozilla-central nightly, after performing the steps from comment 0 on this bug's testcase.

Comment 3

[Tobias (:Tobbi) Markus]

I can reproduce this issue on Windows 7 as well.

I was experiencing it with http://aktuell.de.selfhtml.org/artikel/javascript/textauswahl/sonderzeichen.htm Simply hover your mouse over the table cells. Many of these have artifacts at random borders.

Can someone debug this further?