Seamless server is FUBAR when attaching from Windows

[stdedos]

All windows are either Transparent, White, have leftover drawing (from themselves or previous windows), or have rendered some random state once and froze with it.

"Xpra-Python3-x86_64_4.1-r27002\xpra_cmd" attach ssh://user@ip/2 --ssh="plink -ssh -agent" --modal-windows=no --title="@title@ on @@/@server-display@" --headerbar=off --opengl=no --bandwidth-limit=6Mbps

2020-07-24 13:33:52,951 Xpra GTK3 client version 4.1-r27002 64-bit
2020-07-24 13:33:52,952  running on Microsoft Windows 10
2020-07-24 13:33:53,854 GStreamer version 1.16.2 for Python 3.8.4 64-bit
2020-07-24 13:33:54,367 keyboard layout code 0x409
2020-07-24 13:33:54,368 identified as 'United States - English' : us
2020-07-24 13:33:54,555  keyboard settings: layout=us
2020-07-24 13:33:54,559  desktop size is 4160x1440 with 1 screen:
2020-07-24 13:33:54,561   Default (1100x381 mm - DPI: 96x96) workarea: 4160x1400
2020-07-24 13:33:54,561     Generic PnP Monitor 1600x900 at 0x534 (309x174 mm - DPI: 131x131) workarea: 1600x860 at 0x534
2020-07-24 13:33:54,561     C32JG5x 2560x1440 at 1600x0 (697x392 mm - DPI: 93x93) workarea: 2560x1400 at 1600x0
2020-07-24 13:33:58,784 enabled remote logging
2020-07-24 13:33:58,787 Xpra GTK3 X11 server version 3.0.10-r26630 64-bit
2020-07-24 13:33:58,788  running on Linux Ubuntu 16.04 xenial
2020-07-24 13:33:58,798 Attached to ip:22
2020-07-24 13:33:58,799  (press Control-C to detach)


(xpra_cmd:1768): Pango-WARNING **: 13:34:00.120: couldn't load font "Bitstream Vera Sans Not-Rotated 14.662109375", falling back to "Sans Not-Rotated 14.662109375", expect ugly output.
2020-07-24 13:34:01,144 UI thread is now blocked
2020-07-24 13:34:01,213 UI thread is running again, resuming
2020-07-24 13:34:01,230 Warning: static gravity is not handled

Re-initting / re-connecting client does not work.

Attaching from inside an xpra session on the same server works (crashed on Windows prolly because OpenGL+Headerbar).

Server reports nothing

u@h [2020-07-24 13:36:04]:/run/user/1000/xpra$ bat display-\:2-\$TIMESTAMP.log
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: display-:2-$TIMESTAMP.log
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ xpra initialization error:
   2   │  You already have an xpra server running at /run/user/1000/xpra/u-h-2
   3   │   (did you want 'xpra upgrade'?)
───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────
u@h [2020-07-24 13:36:08]:/run/user/1000/xpra$ bat display-\:2-\$TIMESTAMP.log.old 
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: display-:2-$TIMESTAMP.log.old
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ xpra initialization error:
   2   │  You already have an xpra server running at /run/user/1000/xpra/u-h-2
   3   │   (did you want 'xpra upgrade'?)
───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────

xpra info collected, going for xpra upgrade

[stdedos]

upgrade does not help. I moved all windows to a new session (and now there is no crash on nested attaching) except the gnome-terminal (no way to automatically open X tabs and type a command in them).

Now, xpra-top shows something interesting:

                                Xpra top 3.0.10-r26630
Xpra GTK3 X11 server 64-bit
xpra top - 14:41:37 up 41:06,  1 users, load average: 4.61, 4.15, 3.63
9 threads
cursor at 2111x1437

 ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
 │Python/GTK3 client version 3.0.10-r26630                                                        │
 │batch delay: 18 (25)                                                                            │
 │latency: 0 (0)                                                                                  │
 └────────────────────────────────────────────────────────────────────────────────────────────────┘

2 windows
 ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
 │Terminal                                                                                        │
 │166x158 at 1274,1130                                                                            │
 │override-redirect                                                                               │
 │POPUP_MENU                                                                                      │
 └────────────────────────────────────────────────────────────────────────────────────────────────┘
 ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
 │Terminal                                                                                        │
 │2550x1036 at 1601,97 - base-size=(12, 50), minimum-size=(298, 79), gravity=1, increment=(9, 17) │
 │NORMAL                                                                                          │
 └────────────────────────────────────────────────────────────────────────────────────────────────┘

Which matches a white blob of the aforementioned dimensions.

I tried the "Left-Click,Move-NW,Right-Click,Move-NW" * (inf) trick with the mouse, didn't help.
I tried to see other children of the xpra server, but there are no PIDs listed in top, server.pid=19036 is not valid, and it is boring to manually go through 30+ pids from the info file.

[Antoine Martin]

There are a lot of things I don't really understand in this ticket, so bear with me:

All windows are either Transparent, White, have leftover drawing ..

Even an xterm? gnome-terminal, glxgears?

Attaching from inside an xpra session on the same server works

Nested xpra, cool. So the server is fine?

.. --opengl=no ..

Does opengl make any difference?

--modal-windows=no

FYI: that's been the default since v4 IIRC.

headerbar=off

Also already the default on win32.

Which matches a white blob of the aforementioned dimensions.

Which one? The popup or the normal window?

I tried to see other children of the xpra server

What would those be?

but there are no PIDs listed in top

No, that's a 4.1 feature - which is scheduled to be backported to 3.1 eventually (details in ticket:2553#comment:3)

server.pid=19036 is not valid

That's impossible.
You must be logged into the wrong server.
The pid shown as server.pid is retrieved when requested using ​os.getpid, so it must be valid.

[stdedos]

Replying to Antoine Martin:

There are a lot of things I don't really understand in this ticket, so bear with me:

No worries. I don't understand how much I suck at reporting sometimes 😅

All windows are either Transparent, White, have leftover drawing ..

Even an xterm? gnome-terminal, glxgears?

I didn't attempt to start new window - I just tried to salvage the server ASAP.

Attaching from inside an xpra session on the same server works

Nested xpra, cool. So the server is fine?

I understand that the ticket title is a bit misleading. As always, feel free renaming.

Given that attaching did not allow to interact at all with the server, ginormous delays (I just looked at a seemingly video for minutes, re-attaching gave me the images above), new session worked fine, nested attachment crashed the Windows client of the new session ...
"I couldn't point that being client's fault".

.. --opengl=no ..

Does opengl make any difference?

--modal-windows=no

FYI: that's been the default since v4 IIRC.

headerbar=off

Also already the default on win32.

Keep in mind that I rather play safe than anything else. Also, to be able to work with xpra.
I think it also helps me making "clearer" bug reports to you (I think).

For the opengl flag: Intel Graphics.

Which matches a white blob of the aforementioned dimensions.

Which one? The popup or the normal window?

The white-blob matches the first window, the un-interactable terminal matches the second window.

I tried to see other children of the xpra server

What would those be?

I don't know - I am trying to inspect to gather more data.
I don't know what the white-blob is, and it didn't make sense belonging to the terminal
(Although, thinking of it makes me think "gnome-terminal right click menu")

but there are no PIDs listed in top

No, that's a 4.1 feature - which is scheduled to be backported to 3.1 eventually (details in ticket:2553#comment:3)

server.pid=19036 is not valid

That's impossible.
You must be logged into the wrong server.
The pid shown as server.pid is retrieved when requested using ​os.getpid, so it must be valid.

In this ticket, everything is about the physical Ubuntu 16.04.6 server.

ps faux | grep 19036 gave nothing (I could try it again later).
My implementation of descendant_pids definitely did not return anything
(A function that gives: all the parents of PID X (until PID 1), and all of X's kids, until their leaves).

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/2853