🐛 Delta doesn't highlight matches if `color.grep.match` changed

[joshtriplett]

If the user's git configuration customizes color.grep.match, delta won't recognize and highlight matches.

For instance, here's git grep 'Get Started' in the delta repository with my configuration, which sets color.grep.match = 'bold green':

Here's the same grep with the default git grep color configuration:

Here's the raw text output as a hexdump (using -c color.pager=hd) in both cases:

With color.grep.match = 'bold green':

00000000  1b 5b 33 35 6d 52 45 41  44 4d 45 2e 6d 64 1b 5b  |.[35mREADME.md.[|
00000010  6d 1b 5b 33 36 6d 3a 1b  5b 6d 23 23 20 1b 5b 31  |m.[36m:.[m## .[1|
00000020  3b 33 32 6d 47 65 74 20  53 74 61 72 74 65 64 1b  |;32mGet Started.|
00000030  5b 6d 0a                                          |[m.|
00000033

With the default color.grep.match = 'bold red':

00000000  1b 5b 33 35 6d 52 45 41  44 4d 45 2e 6d 64 1b 5b  |.[35mREADME.md.[|
00000010  6d 1b 5b 33 36 6d 3a 1b  5b 6d 23 23 20 1b 5b 31  |m.[36m:.[m## .[1|
00000020  3b 33 31 6d 47 65 74 20  53 74 61 72 74 65 64 1b  |;31mGet Started.|
00000030  5b 6d 0a                                          |[m.|
00000033

Note the different color code on the ANSI escape right before the match.

I think the most obvious way to fix this would be to retrieve and parse git's color configuration (e.g. using something like anstyle-git), render the result as an ANSI escape sequence, and match against that.

• [x] Please include the raw text output from git, so that we can reproduce the problem. (You can use git --no-pager to produce the raw text output.)
• [x] A screenshot of Delta's output is often helpful also.

Thanks for filing a Delta bug report!