668549 - caret "eats" part of last character in text input

Status: NEW

(Core :: Graphics, defect)

Description

[arno renevier]

Attachment: testcase

Hi,
If I have a text input (or textarea), whose margin is 0.5px (or 1.5px or whatever.5px), the column of text just before the caret is not displayed.
The bug only happens with a fixed background.

Comment 1

[arno renevier]

Attachment: screenshot

screenshot of what I see with testcase.

Comment 2

[arno renevier]

Attachment: screenshot: without fixed background

Screenshot of testcase where I removed the background-attachment line.
Note that this time, caret is close enough of x letter to touch it.

Comment 3

[Mats Palmgren (inactive)]

I can reproduce it in a recent Nightly, but it works fine in Fx 4.0.1 (Linux64)

Comment 4

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

First step would be to find a regression range to identify the guilty person :-)

Comment 5

[arno renevier]

I ran mozregression twice, and got those different results:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0cf4fa02c0f2&tochange=1f25c65e9335
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=836aa9658341&tochange=831f8e040f38

May be the bug is caused by #562746 (updating cairo to 1.10).
Also I've tried with a custom webbrowser running a gecko 2.0 engine build with 
--enable-system-cairo my system cairo version is 1.10
That information seems to confirm the relation with cairo 1.10

Comment 6

[Mats Palmgren (inactive)]

The Cairo update (bug 562746) is in both those ranges (it was backed out
the first time).  Also confirmed the range in Linux64 Nightly builds:
2011-05-27-03 works --  2011-05-28-03 fails.

Comment 7

[Karl Tomlinson (:karlt)]

The last pixel-column of text is initially displayed but is erased when the caret is erased.  Placing the caret "between" the two characters demonstrates that it is only the pixel-column to the left of the caret that is not invalidated/painted correctly.  The pixels "under" the caret are repainted correctly.