[PATCH v2 14/24] commit: implement commit_list_contains()

[Taylor Blau <me@ttaylorr.com>]

From: Derrick Stolee <dstolee@microsoft.com>

It can be helpful to check if a commit_list contains a commit. Use
pointer equality, assuming lookup_commit() was used.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 commit.c | 11 +++++++++++
 commit.h |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/commit.c b/commit.c
index fe1fa3dc41..9a785bf906 100644
--- a/commit.c
+++ b/commit.c
@@ -544,6 +544,17 @@ struct commit_list *commit_list_insert(struct commit *item, struct commit_list *
 	return new_list;
 }
 
+int commit_list_contains(struct commit *item, struct commit_list *list)
+{
+	while (list) {
+		if (list->item == item)
+			return 1;
+		list = list->next;
+	}
+
+	return 0;
+}
+
 unsigned commit_list_count(const struct commit_list *l)
 {
 	unsigned c = 0;
diff --git a/commit.h b/commit.h
index 5467786c7b..742a6de460 100644
--- a/commit.h
+++ b/commit.h
@@ -167,6 +167,8 @@ int find_commit_subject(const char *commit_buffer, const char **subject);
 
 struct commit_list *commit_list_insert(struct commit *item,
 					struct commit_list **list);
+int commit_list_contains(struct commit *item,
+			 struct commit_list *list);
 struct commit_list **commit_list_append(struct commit *commit,
 					struct commit_list **next);
 unsigned commit_list_count(const struct commit_list *l);
-- 
2.29.2.312.gabc4d358d8