736362 - Fx 12, harfbuzz disabled, font rendering regression - spacing too close

Status: RESOLVED INVALID

(Core :: Layout: Text and Fonts, defect)

Description

[al_9x]

Attachment: 11 vs. 12 & 14

1. Fx 12.0b1 & 14.0a1 (2012-03-15), new profile
2. set gfx.font_rendering.harfbuzz.scripts=0
3. restart
4. load https://wiki.mozilla.org/Windows_Service_Silent_Update

problem does not exist in Fx 11.0

Comment 1

[_ck_]

I am experiencing the same problem under Windows XP 32-bit (home)

For me, Harfbuzz set to 2 under Firefox 11 was fine for all websites.

Now under Firefox 12, mixed results on different pages for setting 1,2 or 3.

For fx12 Had to set to zero for decent results on most websites.

Feel free to use this minimal test case  http://jsbin.com/etiyah

Comment 2

[LummoxJR]

I should point out that since Firefox 12, disabling Harfbuzz also causes many pages to space letters too widely. This is very noticeable in Arial, on Google result pages and Wikipedia articles. I am using 32-bit Windows XP, and have hardware rendering mode disabled. This problem appeared in Firefox 12, disappeared during one of the later betas, and then reappeared during the next beta. It persists in at least Firefox 13.

I have found that the LSB in gfx.font_rendering.harfbuzz.scripts is to blame for the spacing. If you set this to 0 or 2 instead of 1 or 3, the weird spacing errors will appear--and you do not have to restart to see this, just switch tabs. Yet if the LSB is on, you also get the stupid kerning problems harfbuzz is infamous for in some fonts, namely with letter pairs like To, Tr, etc.

Comment 3

[Behdad Esfahbod]

HarfBuzz is always enabled now.