resizing one of two displays moves windows to that display

Submitted by Max Kessler

Assigned to Jérôme Guelfucci

Link to original bug (#14797)

Description

I have a dual monitor setup. The primary display (right) supports up to 1920x1080. The secondary display (left) supports up to 3840x2160, but is normally kept at 1920x1080 for readability. When I resize the secondary display for occasional 4k use, all of the windows from the primary display are moved to the secondary display.

Both monitors set to 1920x1080:

Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 16384 x 16384 DVI-0 disconnected (normal left inverted right x axis y axis) HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 600mm x 340mm 3840x2160 30.00 30.00 25.00 24.00 29.97 23.98
2560x1440 59.95
1920x1080 60.00* 60.00 59.94 30.00 24.00 29.97 23.98
1920x1080i 60.00 59.94
1600x900 60.00
1280x1024 60.02
1280x800 59.91
1152x864 59.97
1280x720 60.00 59.94
1024x768 60.00
800x600 60.32
720x480 60.00 59.94
640x480 60.00 59.94
VGA-0 connected primary 1920x1080+1920+0 (normal left inverted right x axis y axis) 480mm x 270mm 1920x1080 60.00*+ 1680x1050 59.95
1400x1050 59.98
1600x900 60.00
1280x1024 75.02 60.02
1440x900 59.89
1280x800 59.81
1152x864 75.00
1280x720 60.00
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 59.94
720x400 70.08

Left 3840x2160, right (primary) 1920x1080:

Screen 0: minimum 320 x 200, current 5760 x 2160, maximum 16384 x 16384
DVI-0 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 3840x2160+0+0 (normal left inverted right x axis y axis) 600mm x 340mm
3840x2160 30.00* 30.00 25.00 24.00 29.97 23.98
2560x1440 59.95
1920x1080 60.00 60.00 59.94 30.00 24.00 29.97 23.98
1920x1080i 60.00 59.94
1600x900 60.00
1280x1024 60.02
1280x800 59.91
1152x864 59.97
1280x720 60.00 59.94
1024x768 60.00
800x600 60.32
720x480 60.00 59.94
640x480 60.00 59.94
VGA-0 connected primary 1920x1080+3840+0 (normal left inverted right x axis y axis) 480mm x 270mm
1920x1080 60.00*+
1680x1050 59.95
1400x1050 59.98
1600x900 60.00
1280x1024 75.02 60.02
1440x900 59.89
1280x800 59.81
1152x864 75.00
1280x720 60.00
1024x768 75.03 60.00
800x600 75.00 60.32
640x480 75.00 59.94
720x400 70.08

Steps to reproduce:

1: With a dual monitor setup, put windows on both displays at 1920x1080. 2: Select the resolution of the secondary display (left) as 3840x2160. 3: Drag the 4k display to the left of the 1080 display in Display settings, aligning the tops. 4: Click Apply.

Version: 4.12.1