368116 - Trunk fonts are occasionally rendered off by 1 pixel, making them appear bolded or italicized

Status: VERIFIED WORKSFORME

(Core :: Graphics, defect)

Description

[emfficc]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a2pre) Gecko/20070124 Minefield/3.0a2pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9a2pre) Gecko/20070124 Minefield/3.0a2pre

The fonts has changed since about one day. Some letters on a page have bold parts. It is difficult to explain what I mean: look at the screenshot I'll attach. The g of "given" and the words "shipping by".
It happens randomly.
When I wipe with another window over the page or when I change the font-size with ctrl+mousewheel, they will redraw better.
Probably caused by Bug 333659 or Bug 367177.
Can't tell more about it.


Reproducible: Always

Steps to Reproduce:
1. Go to e.g. https://bugzilla.mozilla.org/show_bug.cgi?id=368029
2. Look at the font

Actual Results:  
Look at screenshot.

Expected Results:  
Normal font without bold parts.

Comment 1

[emfficc]

Attachment: screenshot

Comment 2

[Ryan Jones-Ward [:sciguyryan]]

Confirming. I've noticed this too, it some fonts also seem to be incorrectly italicised (maybe they aren't being italicised but they appear to be).

Comment 3

[Ryan VanderMeulen [:RyanVM]]

Attachment: Picture of the "italicizing"

To me, this doesn't look like an actual italicizing per se. It's more like the upper or lower half of the glyph is just being shifted over by 1 pixel. If I select/deselect the text, the glyph fixes itself, which suggests it's some rounding error which gets fixed when selecting the text (which I'm guessing forces some kind of recalculation?).  It's the same issue with the "bolding", just another manifestation of the same core problem I'm guessing.

Comment 4

[-fullmetaljacket-]

Attachment: screenshot from tinderbox

[image taken from: http://tinderbox.mozilla.org/showbuilds.cgi?tree=Firefox]

another screenshot showing the 1 pixel shifting (to the left)

Comment 5

[Tulio Serpio]

I believe the bug is trigger by:

* scrolling 
* tooltips over text
* absolute positioned elements witch cover text that became hidden
* dragging other Chrome windows over text

Comment 6

[Jon Henry]

I see the same thing as Ryan in comment 3 quite often.

Comment 8

[Serge Gautherie (:sgautherie)]

(In reply to comment #4)
> another screenshot showing the 1 pixel shifting (to the left)

The shift with that page is to the _right_ (as seen from your screenshot).


[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a3pre) Gecko/20070305 SeaMonkey/1.5a] (nightly) (W2Ksp4)

Confirming, with SeaMonkey:
I can reproduce comment 4.

FWIW, I noticed that on <http://tinderbox.mozilla.org/showbuilds.cgi?tree=SeaMonkey>,
the background area shifts to the _left_ instead.

Comment 9

[-fullmetaljacket-]

(In reply to comment #8)
> The shift with that page is to the _right_ (as seen from your screenshot).

ah yes! to the right ;-)

Comment 11

[Serge Gautherie (:sgautherie)]

(In reply to comment #8)
> <http://tinderbox.mozilla.org/showbuilds.cgi?tree=SeaMonkey>,

[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a5pre) Gecko/20070504 SeaMonkey/1.5a] (nightly) (W2Ksp4)

Actually, depending on zoom setting, which part of the screen moves and in which direction can be different:
anyway, bug still there.

Comment 12

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

Anyone have steps to reliably reproduce?

Comment 13

[Serge Gautherie (:sgautherie)]

[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a5pre) Gecko/20070515 SeaMonkey/1.5a] (nightly) (W2Ksp4)

Robert,
the shift on the tinderbox pages is (still) 100% reproducible...

Comment 14

[Stuart Parmenter]

I can't reproduce this anymore on tinderbox.  Are other still seeing it?

Comment 15

[Serge Gautherie (:sgautherie)]

[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a6pre) Gecko/2007061502 SeaMonkey/2.0a1pre] (nightly) (W2Ksp4)

Bug still there, with new SMv2.0 trunk.
On <http://tinderbox.mozilla.org/showbuilds.cgi?tree=SeaMonkey>.

Comment 16

[Serge Gautherie (:sgautherie)]

(In reply to comment #15)

[Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a6pre) Gecko/2007061602 SeaMonkey/2.0a1pre] (nightly) (W2Ksp4)

(At Zoom=200%) I can still reproduce quite easily.

Comment 17

[John Vandenberg]

Bug 338921 appears to be very similar to this one.

Comment 18

[Mike Connor [:mconnor]]

punting remaining a6 bugs to b1, all of these shipped in a5, so we're at least no worse off by doing so.

Comment 19

[Dão Gottwald [:dao]]

I haven't seen this for quite some time. Anyone else?

Comment 20

[Steve England [:stevee]]

Me neither.

Comment 21

[Serge Gautherie (:sgautherie)]

V.WorksForMe:
it seems the issues were fixed "step by step" during the last 3-4 months... :-)
(Even if not having a reliable (test)case makes it hard to be 100% sure.)