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Master One

Member

From: Europe

Registered: 2007-01-21

Posts: 249

Firefox not remembering window size/position in Gnome Wayland session

I have just switched Firefox from using X11 to Wayland by adding

env MOZ_ENABLE_WAYLAND=1

to the firefox.desktop file and now Firefox does not restore the windows size and position when closing and re-opening. Switching back to X11 solves the issue, but there is no point in running Firefox in X11 when using Gnome only because of that.

I guess this is a known issue? Any easy solution or is this to be solved by the Firefox dev team?

glitsj16

Member

Registered: 2015-04-26

Posts: 126

Re: Firefox not remembering window size/position in Gnome Wayland session

Hi, I had similar issues with window sizing/positioning on Wayland. Whether or not this is by design remains to be seen, but IMO it is not something that is considered a bug but a (privacy) feature. After some hair-pulling I was able to fix it by changing about:config prefs relating to RFP (Resist FingerPrinting). If you by any chance use a custom user.js (or you don't but want more info on possible settings and their effect) I suggest reading / playing around with settings under [Section 4500] and [Section 4600].

Master One

Member

From: Europe

Registered: 2007-01-21

Posts: 249

Re: Firefox not remembering window size/position in Gnome Wayland session

Hi, I had similar issues with window sizing/positioning on Wayland. Whether or not this is by design remains to be seen, but IMO it is not something that is considered a bug but a (privacy) feature. After some hair-pulling I was able to fix it by changing about:config prefs relating to RFP (Resist FingerPrinting). If you by any chance use a custom user.js (or you don't but want more info on possible settings and their effect) I suggest reading / playing around with settings under [Section 4500] and [Section 4600].

Some more testing revealed that it's Wayland being responsible for Firefox not restoring its last position and the enabled setting privacy.resistFingerprinting for Firefox not restoring its last window size but opening in an awkward size (higher than wide] instead.

Interestingly enabling privacy.resistFingerprinting has the opposite effect, entropy went from 16.16 to 17.75 bits of identifying information, so I disabled it again and Firefox at least restores the window size. I'm not using a custom user.js btw.

So that leaves windows placement by Wayland, which is odd and not really desired, but well, better than keeping Firefox in X11 I guess.

glitsj16

Member

Registered: 2015-04-26

Posts: 126

Re: Firefox not remembering window size/position in Gnome Wayland session

Interesting finds. I have privacy.resistFingerprinting disabled too and drop a customized xulstore.json in the FF profile dir prior to each start to set desired window size / position. Here's an example snippet from that file:

{"main-window":{"screenX":"264","screenY":"34","width":"1072","height":"794","sizemode":"normal"}

Let's hope Wayland will mature over time and get tools like devilspie, xdotools, etc. to keep this irritating behavior under wraps...

Master One

Member

From: Europe

Registered: 2007-01-21

Posts: 249

Re: Firefox not remembering window size/position in Gnome Wayland session

customized xulstore.json in the FF profile dir

This should have no influence, because FF correctly stores the window dimensions and position in its xulstore.json file, but can't restore size (if privacy.resistFingerprinting is enabled) and/or position (if in Wayland).

Last edited by Master One (2019-10-15 12:50:47)

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 24,845

Re: Firefox not remembering window size/position in Gnome Wayland session

Tools like xdotools and similar will inherently not exist on "Wayland", it's one of the major points that wayland doesn't allow any random client to arbitrarily adjust the state of another client. They will have to be implemented on the Wayland compositor's side, so this might actually be a GNOME mutter bug that might've to be fixed there rather than in firefox.