Re-attaching session damages server

[stdedos]

Creating the following session:

client r26623, server r26630

"Xpra-Python3_4.0.2-r26623\xpra_cmd" attach ssh://user@ip/20 --ssh="plink -ssh -agent" --modal-windows=no --title="@title@ on @@/@server-display@" --opengl=no --bandwidth-limit=6Mbps

2020-06-25 11:40:20,106 Xpra GTK3 client version 4.0.2-r26623 32-bit
2020-06-25 11:40:20,108  running on Microsoft Windows 10
2020-06-25 11:40:20,885 GStreamer version 1.16.2 for Python 3.8.3 32-bit
2020-06-25 11:40:21,322 keyboard layout code 0x409
2020-06-25 11:40:21,323 identified as 'United States - English' : us
2020-06-25 11:40:21,613  keyboard settings: layout=us
2020-06-25 11:40:21,616  desktop size is 4160x1440 with 1 screen:
2020-06-25 11:40:21,616   Default (1100x380 mm - DPI: 96x96) workarea: 4160x1400
2020-06-25 11:40:21,617     Generic PnP Monitor 1600x900 at 0x534 (309x174 mm - DPI: 131x131) workarea: 1600x860
2020-06-25 11:40:21,617     C32JG5x 2560x1440 at 1600x0 (697x392 mm - DPI: 93x93) workarea: 2560x1400
2020-06-25 11:40:31,411 enabled remote logging
2020-06-25 11:40:31,415 Xpra GTK3 X11 server version 3.0.10-r26630 64-bit
2020-06-25 11:40:31,415  running on Linux Ubuntu 16.04 xenial
2020-06-25 11:40:31,427 Attached to ip:22
2020-06-25 11:40:31,428  (press Control-C to detach)


(xpra_cmd:21588): Pango-WARNING **: 11:40:32.285: couldn't load font "Bitstream Vera Sans Not-Rotated 14.662109375", falling back to "Sans Not-Rotated 14.662109375", expect ugly output.
2020-06-25 11:40:32,832 sound output using 'opus' audio codec
2020-06-25 11:40:33,312 UI thread is now blocked
2020-06-25 11:40:33,329 UI thread is running again, resuming

And then stealing it from server's DISPLAY=:0, gives:

u@h [2020-06-25 16:55:23]:~$ xpra attach 2
2020-06-25 16:56:02,697 Xpra GTK3 X11 client version 3.0.10-r26630 64-bit
2020-06-25 16:56:02,756  running on Linux Ubuntu 16.04 xenial
2020-06-25 16:56:02,760  window manager is 'Compiz'
2020-06-25 16:56:02,844 No OpenGL_accelerate module loaded: No module named 'OpenGL_accelerate'
2020-06-25 16:56:03,077 OpenGL enabled with Quadro P400/PCIe/SSE2
2020-06-25 16:56:03,144  keyboard settings: rules=evdev, model=pc105, layout=us
2020-06-25 16:56:03,146  desktop size is 6400x1440 with 1 screen:
2020-06-25 16:56:03,147   :0.0 (1693x381 mm - DPI: 96x96) workarea: 6341x1416 at 59x24
2020-06-25 16:56:03,147     DP-0 2560x1440 (597x336 mm - DPI: 108x108)
2020-06-25 16:56:03,147     DP-2 1920x1080 at 2560x180 (527x296 mm - DPI: 92x92)
2020-06-25 16:56:03,147     DP-4 1920x1080 at 4480x180 (527x296 mm - DPI: 92x92)
2020-06-25 16:56:03,147  upscaled to 125%, virtual screen size: 5120x1152
2020-06-25 16:56:03,147   :0.0 (1693x381 mm - DPI: 76x76) workarea: 5073x1133 at 47x19
2020-06-25 16:56:03,147     DP-0 2048x1152 (597x336 mm - DPI: 87x87)
2020-06-25 16:56:03,147     DP-2 1536x864 at 2048x144 (527x296 mm - DPI: 74x74)
2020-06-25 16:56:03,147     DP-4 1536x864 at 3584x144 (527x296 mm - DPI: 74x74)
2020-06-25 16:56:03,169 Warning: invalid frame extents value '[0, 0, 0, 0, 0, 0, 28, 0]'
2020-06-25 16:56:03,169  this is probably a bug in 'Compiz'
2020-06-25 16:56:03,169  using '[0, 0, 28, 0]' instead
2020-06-25 16:56:03,281 enabled fast mmap transfers using 281MB shared memory area
2020-06-25 16:56:03,282 enabled remote logging
2020-06-25 16:56:03,282 Xpra GTK3 X11 server version 3.0.10-r26630 64-bit
2020-06-25 16:56:03,282  running on Linux Ubuntu 16.04 xenial
2020-06-25 16:56:03,283  no need for scaling with mmap
2020-06-25 16:56:03,283 setting scaling to 100%:
2020-06-25 16:56:03,285 sending updated screen size to server: 6400x1440 with 1 screens
2020-06-25 16:56:03,285   :0.0 (1693x381 mm - DPI: 96x96) workarea: 6341x1416 at 59x24
2020-06-25 16:56:03,285     DP-0 2560x1440 (597x336 mm - DPI: 108x108)
2020-06-25 16:56:03,285     DP-2 1920x1080 at 2560x180 (527x296 mm - DPI: 92x92)
2020-06-25 16:56:03,285     DP-4 1920x1080 at 4480x180 (527x296 mm - DPI: 92x92)
2020-06-25 16:56:03,289 Attached to socket:///run/user/1000/xpra/user-ix-main-pc-2
2020-06-25 16:56:03,289  (press Control-C to detach)

2020-06-25 16:56:03,375 Connection lost
/usr/lib/python3/dist-packages/xpra/client/gtk_base/gtk_client_base.py:150: Warning: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
  gtk_main()
2020-06-25 16:56:03,392 server does not support xi input devices
2020-06-25 16:56:03,393  server uses: xtest
u@h [2020-06-25 16:56:03]:~$

without attaching anything (a single gnome-terminal).

Server goes on a:

u@h [2020-06-25 16:54:08]:~$ xpra list
Found the following xpra sessions:
/run/user/1000/xpra:
	UNKNOWN session at :2
/run/xpra:
	UNKNOWN session at :2
Re-probing unknown sessions in: /run/xpra, /run/user/1000/xpra
^C
caught KeyboardInterrupt(), exiting

and gets rescued/attached succesfully afterwards

u@h [2020-06-25 16:55:15]:~$ xpra start --use-display=yes :2

Attaching server log (nothing suspicious in my eyes)

[Antoine Martin]

I'm not seeing this problem here.
It could be related to the randr resizing.
Does running the client with --desktop-scaling=no fix things?

[stdedos]

I am also getting this UUID displayed.

Bug or feature?

[stdedos]

Replying to Antoine Martin:

Does running the client with --desktop-scaling=no fix things?

Yes, it does.

55_server_x11.conf is amended with

xvfb = Xvfb +extension GLX +extension Composite -screen 0 7680x4320x24+32

Why does it need to scale? :/

[stdedos]

It seems that "stealing" has nothing to do with this - any attaching after the first "works" (or rather doesn't)