From: Jeff King <peff@peff.net>
Date: Thu, 2 Jul 2026 08:03:19 +0000 (-0400)
Subject: csum-file: provide a function to release checkpoints
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46ba44e1fd6b1a3d71d529f6713821efc26072c9;p=thirdparty%2Fgit.git

csum-file: provide a function to release checkpoints

A hashfile_checkpoint struct is basically just a copy of the hash_ctx
state at a given point in the file. As such, it contains its own
git_hash_ctx which may (depending on the underlying hash implementation)
need to be discarded when we're done with it.

Let's add a "release" function which cleans up the hash context it
holds. I chose "release" here and not "discard" because you'd use this
to clean up every checkpoint, whether you used it or not. As opposed to
git_hash_discard(), which is needed only if you didn't call
git_hash_final().

There are only two callers which use hashfile_checkpoints, and we can
add release calls to both. When built with "SANITIZE=leak
OPENSSL_SHA1_UNSAFE=1", this makes both t1050 and t9300 leak-free.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 82bc6dcc00..a596b0ee2a 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -1214,6 +1214,7 @@ static void stream_blob(uintmax_t len, struct object_id *oidout, uintmax_t mark)
 out:
 	free(in_buf);
 	free(out_buf);
+	hashfile_checkpoint_release(&checkpoint);
 }
 
 /* All calls must be guarded by find_object() or find_mark() to
diff --git a/csum-file.c b/csum-file.c
index 69e3b99254..19805e580a 100644
--- a/csum-file.c
+++ b/csum-file.c
@@ -223,6 +223,11 @@ int hashfile_truncate(struct hashfile *f, struct hashfile_checkpoint *checkpoint
 	return 0;
 }
 
+void hashfile_checkpoint_release(struct hashfile_checkpoint *checkpoint)
+{
+	git_hash_discard(&checkpoint->ctx);
+}
+
 void crc32_begin(struct hashfile *f)
 {
 	f->crc32 = crc32(0, NULL, 0);
diff --git a/csum-file.h b/csum-file.h
index 1d762a64b0..b98bf57060 100644
--- a/csum-file.h
+++ b/csum-file.h
@@ -39,6 +39,7 @@ struct hashfile_checkpoint {
 void hashfile_checkpoint_init(struct hashfile *, struct hashfile_checkpoint *);
 void hashfile_checkpoint(struct hashfile *, struct hashfile_checkpoint *);
 int hashfile_truncate(struct hashfile *, struct hashfile_checkpoint *);
+void hashfile_checkpoint_release(struct hashfile_checkpoint *);
 
 /* finalize_hashfile flags */
 #define CSUM_CLOSE		1
diff --git a/object-file.c b/object-file.c
index 2acc9522df..aeb0d89368 100644
--- a/object-file.c
+++ b/object-file.c
@@ -1639,6 +1639,8 @@ static int index_blob_packfile_transaction(struct odb_transaction_files *transac
 			   state->alloc_written);
 		state->written[state->nr_written++] = idx;
 	}
+
+	hashfile_checkpoint_release(&checkpoint);
 	return 0;
 }