🐛 Mismatch in line numbers between git diff and git add -p

[davidmatas]

Hi,

I'm getting differences in lines number between git diff and git add -p execution. See the following captures:

git add -p

git diff

The correct one is the one I'm getting in git diff.

Versions:

delta: 0.3.0
git: 2.27.0

[yoichi]

The problem occurs when we have following setting in gitconfig:

[interactive]
	diffFilter = delta --color-only
[delta]
	line-numbers = true

More precisely, it is caused since handle_hunk_header_line() is skipped at
https://github.com/dandavison/delta/blob/master/src/delta.rs#L116

On the other hand, if we call handle_hunk_header_line() there even when raw/color-only option is set by changing code as follows,
then git add -p cause error.

The error is caused since an empty line is added in its output for a hunk.

[dandavison]

Hi @davidmatas, @yoichi, thanks very much for opening this, and for the investigation & analysis, and now a PR! (I'm sorry, I thought I'd commented already to acknowledge this helpful issue submission, but apparently my comment didn't get submitted and I didn't realize.)