Subject: [PATCH v3 4/5] blame: add a config option to mark ignored lines

From: Barret Rhoden <[email-masked]>
Date: Tue, 12 Feb 2019 17:27:21 -0500

When ignoring commits, the commit that is blamed might not be
responsible for the change.  Users might want to know when a particular
line has a potentially inaccurate blame.

This patch adds a config option to identify these lines by specifying
blame.markIgnoredFiles.  When this option is set, each blame line is
marked with an '*'.  For example:

278b6158d6fdb (Barret Rhoden  2016-04-11 13:57:54 -0400 26)

appears as:

*278b6158d6fd (Barret Rhoden  2016-04-11 13:57:54 -0400 26)

where the '*' is placed before the commit, and the hash has one fewer
characters.

Signed-off-by: Barret Rhoden <[email-masked]>
---
 Documentation/config/blame.txt | 4 ++++
 blame.c                        | 4 ++++
 blame.h                        | 1 +
 builtin/blame.c                | 9 +++++++++
 4 files changed, 18 insertions(+)

diff --git a/Documentation/config/blame.txt b/Documentation/config/blame.txt
index 4da2788f306d..9f7f0fcf42c9 100644
--- a/Documentation/config/blame.txt
+++ b/Documentation/config/blame.txt
@@ -26,3 +26,7 @@ blame.ignoreRevsFile::
 	`#` are ignored.  This option may be repeated multiple times.  Empty
 	file names will reset the list of ignored revisions.  This option will
 	be handled before the command line option `--ignore-revs-file`.
+
+blame.markIgnoredLines::
+	Mark lines that were changed by an ignored revision with a '*' in the
+	output of linkgit:git-blame[1].
diff --git a/blame.c b/blame.c
index 4427cde95dc5..34debdba1a7f 100644
--- a/blame.c
+++ b/blame.c
@@ -480,6 +480,7 @@ void blame_coalesce(struct blame_scoreboard *sb)
 	for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 		if (ent->suspect == next->suspect &&
 		    ent->s_lno + ent->num_lines == next->s_lno &&
+		    ent->ignored == next->ignored &&
 		    ent->unblamable == next->unblamable) {
 			ent->num_lines += next->num_lines;
 			ent->next = next->next;
@@ -732,6 +733,7 @@ static void split_overlap(struct blame_entry *split,
 	int chunk_end_lno;
 	memset(split, 0, sizeof(struct blame_entry [3]));
 
+	split[0].ignored = split[1].ignored = split[2].ignored = e->ignored;
 	split[0].unblamable = e->unblamable;
 	split[1].unblamable = e->unblamable;
 	split[2].unblamable = e->unblamable;
@@ -854,6 +856,7 @@ static struct blame_entry *split_blame_at(struct blame_entry *e, int len,
 	struct blame_entry *n = xcalloc(1, sizeof(struct blame_entry));
 
 	n->suspect = new_suspect;
+	n->ignored = e->ignored;
 	n->unblamable = e->unblamable;
 	n->lno = e->lno + len;
 	n->s_lno = e->s_lno + len;
@@ -951,6 +954,7 @@ static void blame_chunk(struct blame_entry ***dstq, struct blame_entry ***srcq,
 			blame_origin_decref(e->suspect);
 			e->suspect = blame_origin_incref(parent);
 			e->s_lno += offset;
+			e->ignored = 1;
 			/* The top part of any ignored diff will not exist in
 			 * the parent, and we will never be able to accurately
 			 * blame it.  We'll keep it on the blame list for the
diff --git a/blame.h b/blame.h
index 91664913d7c4..53df8b4c5b3f 100644
--- a/blame.h
+++ b/blame.h
@@ -92,6 +92,7 @@ struct blame_entry {
 	 * scanning the lines over and over.
 	 */
 	unsigned score;
+	int ignored;
 	int unblamable;
 };
 
diff --git a/builtin/blame.c b/builtin/blame.c
index 5f38e9dccddd..46d96905de75 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -53,6 +53,7 @@ static int show_progress;
 static char repeated_meta_color[COLOR_MAXLEN];
 static int coloring_mode;
 static struct string_list ignore_revs_file_list = STRING_LIST_INIT_NODUP;
+static int mark_ignored_lines;
 
 static struct date_mode blame_date_mode = { DATE_ISO8601 };
 static size_t blame_date_width;
@@ -482,6 +483,10 @@ static void emit_other(struct blame_scoreboard *sb, struct blame_entry *ent, int
 			}
 		}
 
+		if (mark_ignored_lines && ent->ignored) {
+			length--;
+			putchar('*');
+		}
 		if (ent->unblamable)
 			memset(hex, '0', length);
 		printf("%.*s", length, hex);
@@ -710,6 +715,10 @@ static int git_blame_config(const char *var, const char *value, void *cb)
 		string_list_insert(&ignore_revs_file_list, str);
 		return 0;
 	}
+	if (!strcmp(var, "blame.markignoredlines")) {
+		mark_ignored_lines = git_config_bool(var, value);
+		return 0;
+	}
 	if (!strcmp(var, "color.blame.repeatedlines")) {
 		if (color_parse_mem(value, strlen(value), repeated_meta_color))
 			warning(_("invalid color '%s' in color.blame.repeatedLines"),
-- 
2.21.0.rc0.258.g878e2cd30e-goog