Open Bug 1493472 Opened Last year Updated 2 months ago

Firefox not remembering window position in windows 10


(Firefox :: Session Restore, defect, P2)

62 Branch
Windows 10



Tracking Status
firefox-esr60 --- unaffected
firefox62 --- wontfix
firefox63 --- wontfix
firefox64 --- wontfix
firefox65 --- fix-optional


(Reporter: bugreport, Unassigned)


(Blocks 1 open bug, Regression)


(Keywords: regression)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0
Build ID: 20180920131237

Steps to reproduce:

Position and resize firefox. Close firefox.

Actual results:

When you reopen firefox, the window position moves up a few pixels.

Expected results:

It should have opened in the same location that it was closed in (previous behavior).
Note: Only noticed when I maximize the height of the window against the top of the screen. Upon reopening, the top of the firefox window is beyond the top edge of the desktop.
Can you confirm that this is still an issue if you update to Firefox 62.0.2? There were a couple of related bugs resolved in that release (1489214 and 1489852).
Flags: needinfo?(bugreport)
I can reproduce on Firefox62.0.2:

1. SNAP ON from Windows10 settings (this settings seems to trigger the bug)
2. Open Firefox62.0.2 and change window sizemode to normal
3. Drag top border of the browser to top of screen edge, the browser window will fit to maximize in height automatically.
4. Quit and relaunch browser
Ever confirmed: true
Keywords: regression
OS: Unspecified → Windows 10
Regression window(m-c):

Regression window(m-release):

And Build from also reproduce the problem.

Regressed by:
e6c9581ba20e	Florian Quèze — Bug 1489214 - Set the position of the early blank window with the screenX/Y attributes rather than with the left/top features to avoid broken CSS <-> device pixel conversions in mixed DPI environments, r=mconley.
Blocks: 1489214
Component: Untriaged → Session Restore
 The patch of Bug 1489214 causes the regression, Can you please look into this?
Flags: needinfo?(florian)
Flags: needinfo?(bugreport)
Duplicate of this bug: 1495405
Priority: -- → P3
Priority: P3 → P2
Too late to fix in 64. Marking this issue as fix-optional for 65; if you land a patch in nightly and think it's low-risk for beta, please request uplift.

This bug is still there for me in Firefox 65.0.1 on Windows 10 x64.

Florian, is this something a backout of bug 1489214 would solve and/ or perhaps you still need to adjust somewhat for the devicePixelRatio after all?

No longer blocks: 1489214
Regressed by: 1489214
See Also: → 1535067

(In reply to Mike de Boer [:mikedeboer] from comment #9)

Florian, is this something a backout of bug 1489214 would solve and/ or perhaps you still need to adjust somewhat for the devicePixelRatio after all?

This seems like a rounding issue, so I expect this to be a problem in platform code. When fixing this it would be great to include tests, as I'm afraid this might remain regression prone.

Flags: needinfo?(florian)

Forgive me if this isn't helpful. I've been trying to find a fix for this for a while now, deleting settings files, removing all addons, uninstalling and re-installing FF. Nothing works. Recorded a video of the behavior in case it is helpful. One strange piece of behavior I've noticed: the window will sometimes re-align itself to the bottom edge of the desktop if I close and re-open FF a second time. (But strangely not to the left or right side.)

Again, apologies if this is not helpful. Love FF, definitely want to see this fixed. It's a small annoyance but it drives me up the wall. =]

I have to agree with ss186262. FF keeps starting a few mm from the left screen edge. When closing it being on the right hand side there is the same gap on the right hand side after a restart. His video shows this clearly!

It might be a small issue but it drives me crazy because I can always see the background picture and icons lingering where the browser should actually be covering them. I´m using FF ESR and struggling to fix this since I switched to Win10 about half a year ago. Snap is deactivated on my system.

Without detracting from the bug, an extension that may alleviate things:

That plugin ^ is not way at all, if wanted to use other applications too.

Nothing helps to get browser size and position to original, when start firefox again. This is everyday problem to me.
Reproduce steps are same as reporter give.

Windows 10 Pro, Firefox 71

I am experiencing exactly the same problem that user ss186262's video shows. System is Windows 10 Home, x64, Firefox version is 70.0. I've had this problem for several months with different Firefox versions. Maybe this bug is not a showstopper, but I'd describe its annoyance level about the same as having a car's steering wheel rotated 10 degrees off-center when driving straight. :)

Regressed by: 1489852
You need to log in before you can comment on or make changes to this bug.