Stuck Alt key when pressingCmd + Shift + 4, then releasing Cmd, Shift and 4 in the same order

[matlupi]

Following the discussion in #345 linked here:

    @lodagro The original issue turned out to be a problem with the TurboVNC Viewer's keyboard handling logic, so this specific issue was not a TigerVNC bug.  You may be experiencing an unrelated issue.

Originally posted by @dcommander in #345 (comment)

My system:
Viewer: v1.11.0 (on macOS 12.5)
Server: v1.9.0 (on CENTOS 7.5)

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[CendioOssman]

I'm a bit confused, are you getting Ctrl stuck even though you don't actually press that specific key?

Exactly how are you seeing that Ctrl is stuck?

[matlupi]

This is the part it took me the most to figure out.
Whenever this bug is manifesting, the keyboard gets remapped as if Ctrl is continuously pressed.
This means (on a terminal, but the same effect is obtained on an open IDE)

Press b -> cursor moves left
Press p -> cursor moves up
Press n -> cursor moves down
etc.

Let me know if you have any additional question.

[CendioOssman]

I tried to reproduce it here, and I'm unable to get the behaviour of a stuck Ctrl. If I press b, it moves one word, which is consistent with a stuck Alt. A stuck Ctrl should move just a single character. At least with bash.

What terminal and shell are you using? In my test it was mate-terminal and bash.

[matlupi]

Sorry for the late reply.

I'm using gnome-terminal and csh.
Versions below:

>> gnome-terminal --version
# GNOME Terminal 3.28.2 using VTE 0.52.5 +GNUTLS
>> csh --version
tcsh 6.18.01 (AStron) 2012-02-14 (x86_64-unknown-linux) options wide,nls,dl,al,kan,sm,rh,color,filec

[CendioOssman]

I tried gnome-terminal (3.44.1) and csh (6.24.01) here, and I'm afraid I'm still just getting a stuck Alt, not a stuck Ctrl.

Just to double check, when everything is working correctly, does the cursor move a single character to the left when you press Ctrl+b? And a whole word when you press Cmd+b?

[matlupi]

I just reproduced the issue and effectively the cursor moves by a full word which is compatible with the Alt key getting stuck.

I can also confirm that when pressing Cmd+b (on a mac, Alt+b on a linux machine) the cursor advances by a whole word in gnome-terminal, in the VNC session.

[CendioOssman]

Great. I just wanted to make sure we're seeing the same thing. Alt should of course also not get wedged.

I think there is a fixe for this in #1375. It's not trivial to port to master, though, but I can try to have a look.

[CendioOssman]

It should be fixed in 4f6d489. Please try the next nightly build and things should work better.