553783 - letter-spacing breaks proper kerning

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect)

Description

[Franz]

User-Agent:       
Build Identifier: 

CSS letter-spacing of 0.02em introduces big gaps between certain letters at least if font-family is "Arial", font-size is 10px and font-weight is bold.

Reproducible: Always

Steps to Reproduce:
1. Open test.html
2. compare the evenness of the letter spacing in both text lines
3.
Actual Results:  
There are big gaps between s-u and e-m

Expected Results:  
No big gaps

Comment 1

[Franz]

Attachment: example

Comment 2

[Franz]

Error occurs in 3.0.18 and 3.5.8. Unfortunately I cannot upload a screenshot. Neither PNG nor JPG is accepted. After clicking "submit" my FF opens a dialog window in order to open "attachment.cgi" with emacs.

Comment 3

[Franz]

Attachment: Screenshot FF 3.5.9 openSUSE 11.1

Comment 4

[Franz]

Attachment: test

Comment 5

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 3.6.13 or later in safe mode? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles

You can also try to reproduce in Firefox 4 Beta 8 or later, there are many improvements in the new version, http://www.mozilla.com/en-US/firefox/all-beta.html

Comment 6

[Tyler Downer [He/Him]]

No reply, INCOMPLETE. Please retest with Firefox 3.6.13 or later and a new profile (http://support.mozilla.com/kb/Managing+profiles). If you continue to see this issue with the newest firefox and a new profile, then please comment on this bug.

Comment 7

[Pablo Couto]

Attachment: Screenshots at varying zoom levels

Comment 8

[Pablo Couto]

I can reproduce this issue on Firefox 52.0.

I used Reporter’s attachment 433704 [details]. The amount of undue separation between some characters, in the `letter-spacing` case, varies with changes in zoom; see attachment 8846862 [details].

Comment 9

[Pablo Couto]

Just to add some info. I tried Reporter’s attachment 433704 [details] on Firefox 52.0.1 for Android and the issue is noticeable, though a bit less. With slight changes in zoom, the characters in letter-spaced text behave as if they were fitting a “grid” of less resolution than the screen displaying them. Maybe the issue has something to do with calculating the proper placement of characters as a function of screen resolution?

I also tested Reporter’s same attachment 433704 [details] with different fonts (DejaVu Sans, DejaVu Serif, Noto Sans) on Firefox 52.0 for desktop, and the issue remains.

UA: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0