cocci: add and apply free_commit_list() rules

Add and apply coccinelle rules to remove "if (E)" before
"free_commit_list(E)", the function can accept NULL, and further
change cases where "E = NULL" followed to also be unconditionally.

The code changes in this commit were entirely made by the coccinelle
rule being added here, and applied with:

    make contrib/coccinelle/free.cocci.patch
    patch -p1 <contrib/coccinelle/free.cocci.patch

The only manual intervention here is that the the relevant code in
commit.c has been manually re-indented.

Suggested-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/commit.c b/commit.c
index 98b2e55..0fee9b1 100644
--- a/commit.c
+++ b/commit.c
@@ -397,17 +397,14 @@ int parse_commit_buffer(struct repository *r, struct commit *item, const void *b
 
 	if (item->object.parsed)
 		return 0;
-
-	if (item->parents) {
-		/*
-		 * Presumably this is leftover from an earlier failed parse;
-		 * clear it out in preparation for us re-parsing (we'll hit the
-		 * same error, but that's good, since it lets our caller know
-		 * the result cannot be trusted.
-		 */
-		free_commit_list(item->parents);
-		item->parents = NULL;
-	}
+	/*
+	 * Presumably this is leftover from an earlier failed parse;
+	 * clear it out in preparation for us re-parsing (we'll hit the
+	 * same error, but that's good, since it lets our caller know
+	 * the result cannot be trusted.
+	 */
+	free_commit_list(item->parents);
+	item->parents = NULL;
 
 	tail += size;
 	if (tail <= bufptr + tree_entry_len + 1 || memcmp(bufptr, "tree ", 5) ||