[PATCH 05/12] commit: force commit to parse from object database

[Derrick Stolee <dstolee@microsoft.com>]

In anticipation of verifying commit-graph file contents against the
object database, create parse_commit_internal() to allow side-stepping
the commit-graph file and parse directly from the object database.

Most consumers expect that if a commit exists in the commit-graph, then
the commit was loaded from the commit-graph so values such as generation
numbers are loaded. Hence, this method should not be called unless the
intention is explicit in avoiding commits from the commit-graph file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 commit.c | 13 +++++++++----
 commit.h |  1 +
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/commit.c b/commit.c
index 1d28677dfb..7c92350373 100644
--- a/commit.c
+++ b/commit.c
@@ -392,7 +392,7 @@ int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long s
 	return 0;
 }
 
-int parse_commit_gently(struct commit *item, int quiet_on_missing)
+int parse_commit_internal(struct commit *item, int quiet_on_missing, int use_commit_graph)
 {
 	enum object_type type;
 	void *buffer;
@@ -403,17 +403,17 @@ int parse_commit_gently(struct commit *item, int quiet_on_missing)
 		return -1;
 	if (item->object.parsed)
 		return 0;
-	if (parse_commit_in_graph(item))
+	if (use_commit_graph && parse_commit_in_graph(item))
 		return 0;
 	buffer = read_sha1_file(item->object.oid.hash, &type, &size);
 	if (!buffer)
 		return quiet_on_missing ? -1 :
 			error("Could not read %s",
-			     oid_to_hex(&item->object.oid));
+					oid_to_hex(&item->object.oid));
 	if (type != OBJ_COMMIT) {
 		free(buffer);
 		return error("Object %s not a commit",
-			     oid_to_hex(&item->object.oid));
+				oid_to_hex(&item->object.oid));
 	}
 	ret = parse_commit_buffer(item, buffer, size, 0);
 	if (save_commit_buffer && !ret) {
@@ -424,6 +424,11 @@ int parse_commit_gently(struct commit *item, int quiet_on_missing)
 	return ret;
 }
 
+int parse_commit_gently(struct commit *item, int quiet_on_missing)
+{
+	return parse_commit_internal(item, quiet_on_missing, 1);
+}
+
 void parse_commit_or_die(struct commit *item)
 {
 	if (parse_commit(item))
diff --git a/commit.h b/commit.h
index b5afde1ae9..5fde74fcd7 100644
--- a/commit.h
+++ b/commit.h
@@ -73,6 +73,7 @@ struct commit *lookup_commit_reference_by_name(const char *name);
 struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name);
 
 int parse_commit_buffer(struct commit *item, const void *buffer, unsigned long size, int check_graph);
+int parse_commit_internal(struct commit *item, int quiet_on_missing, int use_commit_graph);
 int parse_commit_gently(struct commit *item, int quiet_on_missing);
 static inline int parse_commit(struct commit *item)
 {
-- 
2.16.2.329.gfb62395de6