932634 - layout.css.dpi is ignored in Firefox 27

Status: RESOLVED INVALID

(Core :: Graphics, defect)

Description

[Terrell Kelley]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:24.0) Gecko/20100101 Firefox/24.0 (Beta/Release)
Build ID: 20130915200815

Steps to reproduce:

I set layout.css.dpi to 1, in order to run Nightly at 96dpi, to see if DPI scaling was contributing to another bug.


Actual results:

Firefox continued to use the Windows system DPI setting of 120dpi.



Expected results:

Firefox should use a DPI setting of 96 dpi.

Other Info:

I also tried using 96 and even 0 for the setting. The results were the same, The pref is being completely ignored.

This is a commonly used pref. A lot of people freaked out when you implemented DPI scaling on Windows in Firefox 22, and used this pref along with a font-scaling addon to get things back to the way they were. If you ignore this pref, providing them with no other way to get back to the behavior pre-Firefox 22, these users will likely switch browsers. See https://www.google.com/search?q=firefox+22+big+fonts for more.

Comment 1

[Frank Wein [:mcsmurf]]

Isn't this the wrong pref? I thought you need to set layout.css.devPixelsPerPx to 1.0? layout.css.dpi is for setting the dpi itself (for example 96).

Comment 2

[Terrell Kelley]

Okay, I feel stupid now. I just typed DPI in and saw that one, and assumed it was the right pref.

Personally, I think the pref should have DPI in the name so that it would be easier to discover. But that still doesn't excuse not checking to make sure it was the right pref.