Re: [PATCH 1/4] diff.c: emit_line_0 to take string instead of first sign

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

Hi Stefan,

On Fri, 10 Aug 2018, Stefan Beller wrote:

> By providing a string as the first part of the emission we can extend
> it later more easily.

Thank you for working on this!

> While at it, document emit_line_0.
> 
> [...]
>  
> +/*
> + * Emits
> + * <set_sign> <first> <reset> <set> <second> <reset> LF
> + * if they are present. 'first' is a NULL terminated string,
> + * 'second' is a buffer of length 'len'.
> + */

That does not make it clear what the role of `first` or `second` is. Could
you clarify that?

(TBH I am not so sure myself what roles they serve. Previously, it was
kind of obvious to me that `first` tried to specify the diff marker, if
any. But now...?)

The rest looks good to me.

Thanks,
Dscho

>  static void emit_line_0(struct diff_options *o,
>  			const char *set_sign, const char *set, const char *reset,
> -			int first, const char *line, int len)
> +			const char *first, const char *second, int len)
>  {
>  	int has_trailing_newline, has_trailing_carriage_return;
>  	int reverse = !!set && !!set_sign;
> @@ -633,11 +639,11 @@ static void emit_line_0(struct diff_options *o,
>  
>  	fputs(diff_line_prefix(o), file);
>  
> -	has_trailing_newline = (len > 0 && line[len-1] == '\n');
> +	has_trailing_newline = (len > 0 && second[len-1] == '\n');
>  	if (has_trailing_newline)
>  		len--;
>  
> -	has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
> +	has_trailing_carriage_return = (len > 0 && second[len-1] == '\r');
>  	if (has_trailing_carriage_return)
>  		len--;
>  
> @@ -655,7 +661,7 @@ static void emit_line_0(struct diff_options *o,
>  	}
>  
>  	if (first)
> -		fputc(first, file);
> +		fputs(first, file);
>  
>  	if (!len)
>  		goto end_of_line;
> @@ -666,7 +672,7 @@ static void emit_line_0(struct diff_options *o,
>  		fputs(set, file);
>  		needs_reset = 1;
>  	}
> -	fwrite(line, len, 1, file);
> +	fwrite(second, len, 1, file);
>  	needs_reset |= len > 0;
>  
>  end_of_line:
> @@ -681,7 +687,7 @@ 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, NULL, reset, 0, line, len);
> +	emit_line_0(o, set, NULL, reset, NULL, line, len);
>  }
>  
>  enum diff_symbol {
> @@ -1201,7 +1207,7 @@ static void dim_moved_lines(struct diff_options *o)
>  static void emit_line_ws_markup(struct diff_options *o,
>  				const char *set_sign, const char *set,
>  				const char *reset,
> -				char sign, const char *line, int len,
> +				const char *sign, const char *line, int len,
>  				unsigned ws_rule, int blank_at_eof)
>  {
>  	const char *ws = NULL;
> @@ -1244,7 +1250,7 @@ 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, NULL, reset, '\\',
> +		emit_line_0(o, context, NULL, reset, "\\",
>  			    nneof, strlen(nneof));
>  		break;
>  	case DIFF_SYMBOL_SUBMODULE_HEADER:
> @@ -1282,7 +1288,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
>  			else if (c == '-')
>  				set = diff_get_color_opt(o, DIFF_FILE_OLD);
>  		}
> -		emit_line_ws_markup(o, set_sign, set, reset, ' ', line, len,
> +		emit_line_ws_markup(o, set_sign, set, reset, " ", line, len,
>  				    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
>  		break;
>  	case DIFF_SYMBOL_PLUS:
> @@ -1325,7 +1331,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
>  				set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
>  			flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
>  		}
> -		emit_line_ws_markup(o, set_sign, set, reset, '+', line, len,
> +		emit_line_ws_markup(o, set_sign, set, reset, "+", line, len,
>  				    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
>  				    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
>  		break;
> @@ -1368,7 +1374,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
>  			else
>  				set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
>  		}
> -		emit_line_ws_markup(o, set_sign, set, reset, '-', line, len,
> +		emit_line_ws_markup(o, set_sign, set, reset, "-", line, len,
>  				    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
>  		break;
>  	case DIFF_SYMBOL_WORDS_PORCELAIN:
> -- 
> 2.18.0.865.gffc8e1a3cd6-goog
> 
>