unpack-file: fix ancient leak in create_temp_file()

Fix a leak that's been with us since 3407bb4940 (Add "unpack-file"
helper that unpacks a sha1 blob into a tmpfile., 2005-04-18). See
00c8fd493a (cat-file: use streaming API to print blobs, 2012-03-07)
for prior art which shows the same API pattern, i.e. free()-ing the
result of read_object_file() after it's used.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

builtin/unpack-file.c

@@ -19,6 +19,7 @@ static char *create_temp_file(struct object_id *oid)
 	if (write_in_full(fd, buf, size) < 0)
 		die_errno("unable to write temp-file");
 	close(fd);
+	free(buf);
 	return path;
 }
 

t/t6060-merge-index.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='basic git merge-index / git-merge-one-file tests'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup diverging branches' '

t/t6401-merge-criss-cross.sh

@@ -8,6 +8,8 @@
 
 
 test_description='Test criss-cross merge'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'prepare repository' '

t/t6406-merge-attr.sh

@@ -8,6 +8,7 @@ test_description='per path merge controlled by merge attribute'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '

t/t6407-merge-binary.sh

@@ -5,6 +5,7 @@ test_description='ask merge-recursive to merge binary files'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '

t/t7605-merge-resolve.sh

@@ -4,6 +4,7 @@ test_description='git merge
 
 Testing the resolve strategy.'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '