diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_MARKER

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff.c

@@ -561,13 +561,20 @@ static void emit_line(struct diff_options *o, const char *set, const char *reset
 }
 
 enum diff_symbol {
+	DIFF_SYMBOL_CONTEXT_MARKER,
 	DIFF_SYMBOL_SEPARATOR
 };
 
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len)
 {
+	const char *context, *reset;
 	switch (s) {
+	case DIFF_SYMBOL_CONTEXT_MARKER:
+		context = diff_get_color_opt(o, DIFF_CONTEXT);
+		reset = diff_get_color_opt(o, DIFF_RESET);
+		emit_line(o, context, reset, line, len);
+		break;
 	case DIFF_SYMBOL_SEPARATOR:
 		fprintf(o->file, "%s%c",
 			diff_line_prefix(o),
@@ -662,7 +669,8 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
 	if (len < 10 ||
 	    memcmp(line, atat, 2) ||
 	    !(ep = memmem(line + 2, len - 2, atat, 2))) {
-		emit_line(ecbdata->opt, context, reset, line, len);
+		emit_diff_symbol(ecbdata->opt,
+				 DIFF_SYMBOL_CONTEXT_MARKER, line, len);
 		return;
 	}
 	ep += 2; /* skip over @@ */