ansi escape for change background color not work, cont'd

[egmontkob]

Since I can't reopen an existing issue, let me file a new one as a reminder:

#1455 "ansi escape for change background color not work" has been closed, although it's not fixed. echo -ne '\e]11;#ABCDEF\a' does not update the background color.

COMPILE_VTE_BACKGROUND_COLOR should automatically be enabled if a new enough VTE is detected.

(On a side note, flipping the constant and doing an incremental rebuild is not necessary, a full rebuild is needed. This was reported by someone else, and I confirm it with the meson+ninja build system. This means that some compile dependencies are missing.)

[egmontkob]

@gnunn1 You might want to reopen the said bug and close this one. That way precious comments are kept at one place, and the right people are notified.

[fboender]

Confirmed that this is broken in versions after v1.7.7. Downgrading to v1.7.7 fixes this problem.

Changing the background color through a ANSI escape sequence may seem like a small useless feature, but it is the only reliable way I've found so far to change the background color when starting an ssh session. See https://github.com/fboender/sshbg

[the-allanc]

@fboender If you're interested - I took your sshbg script, adapted it so that it could integrate with Tilix's automatic profile switching as a solution, and also added code to try to determine the current terminal window background. You can find it here.