284970 - rendering many things--constant movement of one pixel

Status: RESOLVED INVALID

(SeaMonkey :: General, defect)

Description

[Kris Bolino]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041221
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20041221

Platform: Linux (given builds & my own) (i have also experienced this with
FreeBSD, NetBSD)
Library notes: This problem is more frequent when compiled with libXft
(X11/FreeType) but occurs without it as well.

Applies to: The rendering of many things--favicons in tabs/bookmarks, inline
images, and text

What happens: When the page loads, everything is fine.  Movement of the mouse
over any of the affected things causes them to "jump" one pixel up, down, left,
or right.  Clicking and selection do this as well.  They will periodically jump
back to their old positions with add'l mouse movement, scrolling, or window
focus changes.



Reproducible: Sometimes

Steps to Reproduce:
1. Download/make and use a Linux build
2. View any page (mozilla.org is a good example)
3. Move the mouse across images, select text, create tabs, view pages with favicons

Actual Results:  
The items (or portions of them) jump one pixel.

Expected Results:  
The positions should have remained static.

Comment 1

[Kris Bolino]

Attachment: favicon before mouseover

Comment 2

[Kris Bolino]

Attachment: favicon after mouseover

Comment 3

[Kris Bolino]

Attachment: firefox download before selection

Comment 4

[Kris Bolino]

Attachment: firefox download link after selection

Comment 5

[Kris Bolino]

Attachment: mozilla.org navbar before mouseover

Comment 6

[Kris Bolino]

Attachment: mozilla.org navbar during mouseover (w/o cursor)

Comment 7

[Kris Bolino]

This "bug" is actually due to the dots-per-inch setting for Font rendering. 
Setting this away from "System setting" to something more reasonable, like say
96 dpi seems to fix it.  This isn't so much a "fix" as it is a work around.