Re: [PATCH 5/8] diff.c: add set_sign to emit_line_0

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Stefan,

On Fri, 10 Aug 2018, Stefan Beller wrote:

> For now just change the signature, we'll reason about the actual
> change in a follow up patch.
> 
> Pass 'set_sign' (which is output before the sign) and 'set' which
> controls the color after the first character. Hence, promote any
> 'set's to 'set_sign' as we want to have color before the sign
> for now.

I'll freely admit that I had to study the diff in order to understand this
paragraph.

My I suggest something along those lines instead?

	Split the meaning of the `set` parameter that is passed to
	`emit_line_0()` to separate between the color of the "sign" (i.e.
	the diff marker '+', '-' or ' ' that is passed in as the `first`
	parameter) and the color of the rest of the line.

	This changes the meaning of the `set` parameter to no longer refer
	to the color of the diff marker, but instead to refer to the color
	of the rest of the line. A value of `NULL` indicates that the rest
	of the line wants to be colored the same as the diff marker.

Ciao,
Dscho

> 
> Signed-off-by: Stefan Beller <sbeller@google.com>
> Signed-off-by: Junio C Hamano <gitster@pobox.com>
> ---
>  diff.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/diff.c b/diff.c
> index ab6e6a88a56..5eea5edca50 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -622,7 +622,7 @@ static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
>  }
>  
>  static void emit_line_0(struct diff_options *o,
> -			const char *set, unsigned reverse, const char *reset,
> +			const char *set_sign, const char *set, unsigned reverse, const char *reset,
>  			int first, const char *line, int len)
>  {
>  	int has_trailing_newline, has_trailing_carriage_return;
> @@ -652,9 +652,12 @@ static void emit_line_0(struct diff_options *o,
>  	if (len || !nofirst) {
>  		if (reverse && want_color(o->use_color))
>  			fputs(GIT_COLOR_REVERSE, file);
> -		fputs(set, file);
> +		if (set_sign && set_sign[0])
> +			fputs(set_sign, file);
>  		if (first && !nofirst)
>  			fputc(first, file);
> +		if (set)
> +			fputs(set, file);
>  		fwrite(line, len, 1, file);
>  		fputs(reset, file);
>  	}
> @@ -667,7 +670,7 @@ static void emit_line_0(struct diff_options *o,
>  static void emit_line(struct diff_options *o, const char *set, const char *reset,
>  		      const char *line, int len)
>  {
> -	emit_line_0(o, set, 0, reset, line[0], line+1, len-1);
> +	emit_line_0(o, set, NULL, 0, reset, line[0], line+1, len-1);
>  }
>  
>  enum diff_symbol {
> @@ -1199,17 +1202,17 @@ static void emit_line_ws_markup(struct diff_options *o,
>  	}
>  
>  	if (!ws && !set_sign)
> -		emit_line_0(o, set, 0, reset, sign, line, len);
> +		emit_line_0(o, set, NULL, 0, reset, sign, line, len);
>  	else if (!ws) {
>  		/* Emit just the prefix, then the rest. */
> -		emit_line_0(o, set_sign, !!set_sign, reset, sign, "", 0);
> -		emit_line_0(o, set, 0, reset, 0, line, len);
> +		emit_line_0(o, set_sign, NULL, !!set_sign, reset, sign, "", 0);
> +		emit_line_0(o, set, NULL, 0, reset, 0, line, len);
>  	} else if (blank_at_eof)
>  		/* Blank line at EOF - paint '+' as well */
> -		emit_line_0(o, ws, 0, reset, sign, line, len);
> +		emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
>  	else {
>  		/* Emit just the prefix, then the rest. */
> -		emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
> +		emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
>  			    sign, "", 0);
>  		ws_check_emit(line, len, ws_rule,
>  			      o->file, set, reset, ws);
> @@ -1233,7 +1236,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
>  		context = diff_get_color_opt(o, DIFF_CONTEXT);
>  		reset = diff_get_color_opt(o, DIFF_RESET);
>  		putc('\n', o->file);
> -		emit_line_0(o, context, 0, reset, '\\',
> +		emit_line_0(o, context, NULL, 0, reset, '\\',
>  			    nneof, strlen(nneof));
>  		break;
>  	case DIFF_SYMBOL_SUBMODULE_HEADER:
> -- 
> 2.18.0.865.gffc8e1a3cd6-goog
> 
>