blame: fix coloring for repeated suspects

The option --ignore-rev passes the blame to an older commit.  This can
cause adjacent scoreboard entries to blame the same commit.  Currently
we only look at the present entry when determining whether a line needs
to be colored for --color-lines.  Check the previous entry as well.

Reported-by: Seth McDonald <sethmcmail@pm.me>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: rscharfe

builtin/blame.c

@@ -461,7 +461,8 @@ static void determine_line_heat(struct commit_info *ci, const char **dest_color)
 	*dest_color = colorfield[i].col;
 }
 
-static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int opt)
+static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent,
+		       int opt, struct blame_entry *prev_ent)
 {
 	int cnt;
 	const char *cp;
@@ -492,7 +493,10 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int
 			the_hash_algo->hexsz : (size_t) abbrev;
 
 		if (opt & OUTPUT_COLOR_LINE) {
-			if (cnt > 0) {
+			if (cnt > 0 ||
+			    (prev_ent &&
+			     oideq(&suspect->commit->object.oid,
+				   &prev_ent->suspect->commit->object.oid))) {
 				color = repeated_meta_color;
 				reset = GIT_COLOR_RESET;
 			} else  {
@@ -578,7 +582,7 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int
 
 static void output(struct blame_scoreboard *sb, int option)
 {
-	struct blame_entry *ent;
+	struct blame_entry *ent, *prev_ent = NULL;
 
 	if (option & OUTPUT_PORCELAIN) {
 		for (ent = sb->ent; ent; ent = ent->next) {
@@ -600,7 +604,8 @@ static void output(struct blame_scoreboard *sb, int option)
 		if (option & OUTPUT_PORCELAIN)
 			emit_porcelain(sb, ent, option);
 		else {
-			emit_other(sb, ent, option);
+			emit_other(sb, ent, option, prev_ent);
+			prev_ent = ent;
 		}
 	}
 }

t/t8012-blame-colors.sh

@@ -28,6 +28,20 @@ test_expect_success 'colored blame colors contiguous lines' '
 	test_line_count = 3 H.expect
 '
 
+test_expect_success 'color lines becoming contiguous due to --ignore-rev' '
+	mv hello.c hello.orig &&
+	sed "s/	/    /g" <hello.orig >hello.c &&
+	git add hello.c &&
+	git commit -m"tabs to spaces" &&
+	git -c color.blame.repeatedLines=yellow blame --color-lines --ignore-rev=HEAD hello.c >actual.raw &&
+	test_decode_color <actual.raw >actual &&
+	grep "<YELLOW>" <actual >darkened &&
+	grep "(F" darkened > F.expect &&
+	grep "(H" darkened > H.expect &&
+	test_line_count = 2 F.expect &&
+	test_line_count = 3 H.expect
+'
+
 test_expect_success 'color by age consistently colors old code' '
 	git blame --color-by-age hello.c >actual.raw &&
 	git -c blame.coloring=highlightRecent blame hello.c >actual.raw.2 &&