diff.c: the builtin_diff() deals with only two-file comparison

The combined diff is implemented in combine_diff() and fn_out_consume()
codepath never has to deal with anything but two-file comparision.

Drop nparents from the emit_callback structure and simplify the code.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/diff.c b/diff.c
index 6fea3c03476ac1817453a61fad0cda93a954df9a..1eddd590ec745b57d4c0305a35d8d3744bd30ad6 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -489,7 +489,7 @@ typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 
 struct emit_callback {
        struct xdiff_emit_state xm;
-       int nparents, color_diff;
+       int color_diff;
        unsigned ws_rule;
        sane_truncate_fn truncate;
        const char **label_path;
@@ -549,9 +549,8 @@ static void emit_add_line(const char *reset, struct emit_callback *ecbdata, cons
                emit_line(ecbdata->file, set, reset, line, len);
        else {
                /* Emit just the prefix, then the rest. */
-               emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
-               ws_check_emit(line + ecbdata->nparents,
-                             len - ecbdata->nparents, ecbdata->ws_rule,
+               emit_line(ecbdata->file, set, reset, line, 1);
+               ws_check_emit(line + 1, len - 1, ecbdata->ws_rule,
                              ecbdata->file, set, reset, ws);
        }
 }
@@ -576,7 +575,6 @@ static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, u
 
 static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
-       int i;
        int color;
        struct emit_callback *ecbdata = priv;
        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
@@ -598,13 +596,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
 
-       /* This is not really necessary for now because
-        * this codepath only deals with two-way diffs.
-        */
-       for (i = 0; i < len && line[i] == '@'; i++)
-               ;
-       if (2 <= i && i < len && line[i] == ' ') {
-               ecbdata->nparents = i - 1;
+       if (line[0] == '@') {
                len = sane_truncate_line(ecbdata, line, len);
                emit_line(ecbdata->file,
                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
@@ -614,15 +606,12 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                return;
        }
 
-       if (len < ecbdata->nparents) {
+       if (len < 1) {
                emit_line(ecbdata->file, reset, reset, line, len);
                return;
        }
 
        color = DIFF_PLAIN;
-       if (ecbdata->diff_words && ecbdata->nparents != 1)
-               /* fall back to normal diff */
-               free_diff_words_data(ecbdata);
        if (ecbdata->diff_words) {
                if (line[0] == '-') {
                        diff_words_append(line, len,
@@ -641,13 +630,10 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                emit_line(ecbdata->file, plain, reset, line, len);
                return;
        }
-       for (i = 0; i < ecbdata->nparents && len; i++) {
-               if (line[i] == '-')
-                       color = DIFF_FILE_OLD;
-               else if (line[i] == '+')
-                       color = DIFF_FILE_NEW;
-       }
-
+       if (line[0] == '-')
+               color = DIFF_FILE_OLD;
+       else if (line[0] == '+')
+               color = DIFF_FILE_NEW;
        if (color != DIFF_FILE_NEW) {
                emit_line(ecbdata->file,
                          diff_get_color(ecbdata->color_diff, color),