[Terminal] color support issue

[bipolar]

Since hrev56011 Midnight Commander (MC) complains about lack of 256 color support (if one of the 256-colors themes was previously set up as default).

To make it work again, one needs to call it like this: > TERM=xterm-256color mc (or set that TERM in .bashrc, I guess).

Looking around on the internet for info on this, I've found that a common suggestion is to use two environmental variables to signal 24 bit color support: TERM=xterm-256color AND COLORTERM=truecolor.

See for example, the following pages:

​https://www.gnu.org/software/emacs/manual/html_node/efaq/Colors-on-a-TTY.html

​https://github.com//termstandard/colors

Also, the ticket for MC that added 24-bit color support calls for the use of COLORTERM:

​https://midnight-commander.org/ticket/3724

Even the new "Windows Terminal" team seems to debate about this:

​https://github.com/microsoft/terminal/issues/12174

​https://github.com/microsoft/terminal/issues/11057

P.S.: 24-bits on MC won't work in any case, at it complains about not supporting that while compiled against ncurses. I should create an issue on HaikuPorts to see if it can be compiled against slang-2.3.x instead (now that we have an .hpkg for that).

Edit: Created said ​ticket on HaikuPorts.

[korli]

jessicah, could you look at this? hrev56011 changed TERM it seems. Would the suggestion with the addition of COLORTERM make sense? Thanks.

[korli]

change: ​https://review.haiku-os.org/c/haiku/+/5249

[waddlesplash]

Merged in hrev56063.