'watch' is not interpreting the implicit 'reset' color code `^[m`

Question

It appears that watch is not interpret the implicit 'reset' color code ^[m. It does interpret the explicit code ^[0m.

Does anyone know how to fix this? Or does it sound like a bug and I need to contact the maintainers of watch?

Why I'm asking:

I'm using watch with git log, and git log uses implicit resets ^[m.

Example:

$ watch -c git log --oneline --decorate --source --graph --color=always

What it should look like is:

$ git log --oneline --decorate --source --graph --color=always

Investigation

If we don't include the -c (--color) option on watch, we can see that the ANSI escape codes are there:

Every 2.0s: git log --oneline --decorate --source --graph --color=always                                                                                                                                                                               Fri Sep 28 08:17:42 2018

* ^[33m9db218b^[m       HEAD^[33m (^[m^[1;36mHEAD^[m^[33m -> ^[m^[1;32mmaster^[m^[33m, ^[m^[1;33mtag: v0.8.0b5^[m^[33m, ^[m^[1;31morigin/master^[m^[33m, ^[m^[1;31morigin/HEAD^[m^[33m)^[m Doc updates for v0.8.0b5 release
* ^[33mfd342d9^[m       HEAD Update changelog [ci skip]
* ^[33md1af865^[m       HEAD Update changelog
*   ^[33m70889fa^[m     HEAD Merge branch 'testing-updates' into 'master'

There's a lot going on in the above example - let's simplify it:

Prove that we're escaping things correctly:

$ echo -e "\033[33myellow\033[mnormal"

Send it to watch

Note: the -e arg on echo is not parsed because we're quoting things. watch now handles the color codes.

$ watch -c 'echo -e "\033[33myellow\033[mnormal"'

Remove the -c flag from watch

$ watch 'echo -e "\033[33myellow\033[mnormal"'
Every 2.0s: echo -e "\033[33myellow\033[mnormal"      Fri Sep 28 08:29:26 2018

-e ^[33myellow^[mnormal

This looks as expected.

Using the explicit ^[0m reset code works

$ watch -c 'echo -e "\033[33myellow\033[0mnormal"'

Versions

Primarily tested under WSL: Window 10 Pro, v1803, build 17134.286

$ watch -v
watch from procps-ng 3.3.10
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.5 LTS
Release:        16.04
Codename:       xenial
$ uname -a
Linux redacted-hostname 4.4.0-17134-Microsoft #285-Microsoft Thu Aug 30 17:31:00 PST 2018 x86_64 x86_64 x86_64 GNU/Linux
$ git --version
git version 2.7.4

Also tested using PuTTY to a linux machine. Same version information as above, just not using WSL.

Answer 1

Looks like it was fixed in version 3.3.12 of procps, which contains watch:

https://gitlab.com/procps-ng/procps/issues/12

https://gitlab.com/procps-ng/procps/commit/6fcb690099bd681930946492e8a93c61e82249d8