cat-file: fix a common "struct object_context" memory leak

Fix a memory leak where "cat-file" will leak the "path" member. See
e5fba60 (textconv: support for cat_file, 2010-06-15) for the code
that introduced the offending get_oid_with_context() call (called
get_sha1_with_context() at the time).

As a result we can mark several tests as passing with SANITIZE=leak
using "TEST_PASSES_SANITIZE_LEAK=true".

As noted in dc944b6 (get_sha1_with_context: dynamically allocate
oc->path, 2017-05-19) callers must free the "path" member. That same
commit added the relevant free() to this function, but we weren't
catching cases where we'd return early.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/cat-file.c

@@ -71,6 +71,7 @@ static int stream_blob(const struct object_id *oid)
 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 			int unknown_type)
 {
+	int ret;
 	struct object_id oid;
 	enum object_type type;
 	char *buf;
@@ -106,7 +107,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 		if (sb.len) {
 			printf("%s\n", sb.buf);
 			strbuf_release(&sb);
-			return 0;
+			ret = 0;
+			goto cleanup;
 		}
 		break;
 
@@ -115,16 +117,19 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 		if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
 			die("git cat-file: could not get object info");
 		printf("%"PRIuMAX"\n", (uintmax_t)size);
-		return 0;
+		ret = 0;
+		goto cleanup;
 
 	case 'e':
 		return !has_object_file(&oid);
 
 	case 'w':
 
 		if (filter_object(path, obj_context.mode,
-				  &oid, &buf, &size))
-			return -1;
+				  &oid, &buf, &size)) {
+			ret = -1;
+			goto cleanup;
+		}
 		break;
 
 	case 'c':
@@ -143,11 +148,14 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 			const char *ls_args[3] = { NULL };
 			ls_args[0] =  "ls-tree";
 			ls_args[1] =  obj_name;
-			return cmd_ls_tree(2, ls_args, NULL);
+			ret = cmd_ls_tree(2, ls_args, NULL);
+			goto cleanup;
 		}
 
-		if (type == OBJ_BLOB)
-			return stream_blob(&oid);
+		if (type == OBJ_BLOB) {
+			ret = stream_blob(&oid);
+			goto cleanup;
+		}
 		buf = read_object_file(&oid, &type, &size);
 		if (!buf)
 			die("Cannot read object %s", obj_name);
@@ -172,8 +180,10 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 			} else
 				oidcpy(&blob_oid, &oid);
 
-			if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
-				return stream_blob(&blob_oid);
+			if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB) {
+				ret = stream_blob(&blob_oid);
+				goto cleanup;
+			}
 			/*
 			 * we attempted to dereference a tag to a blob
 			 * and failed; there may be new dereference
@@ -193,9 +203,11 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
 		die("git cat-file %s: bad file", obj_name);
 
 	write_or_die(1, buf, size);
+	ret = 0;
+cleanup:
 	free(buf);
 	free(obj_context.path);
-	return 0;
+	return ret;
 }
 
 struct expand_data {

t/t0028-working-tree-encoding.sh

@@ -5,6 +5,7 @@ test_description='working-tree-encoding conversion via gitattributes'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY/lib-encoding.sh"
 

t/t1051-large-conversion.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='test conversion filters on large files'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 set_attr() {

t/t3304-notes-mixed.sh

@@ -5,6 +5,7 @@ test_description='Test notes trees that also contain non-notes'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 number_of_commits=100

t/t4044-diff-index-unique-abbrev.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='test unique sha1 abbreviation on "index from..to" line'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup' '

t/t4140-apply-ita.sh

@@ -2,6 +2,7 @@
 
 test_description='git apply of i-t-a file'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success setup '

t/t5314-pack-cycle-detection.sh

@@ -49,9 +49,9 @@ Then no matter which order we start looking at the packs in, we know that we
 will always find a delta for "file", because its lookup will always come
 immediately after the lookup for "dummy".
 '
-. ./test-lib.sh
-
 
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
 
 # Create a pack containing the tree $1 and blob $1:file, with
 # the latter stored as a delta against $2:file.

t/t6422-merge-rename-corner-cases.sh

@@ -6,6 +6,7 @@ test_description="recursive merge corner cases w/ renames but not criss-crosses"
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-merge.sh
 

t/t8007-cat-file-textconv.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='git cat-file textconv support'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 cat >helper <<'EOF'

t/t8010-cat-file-filters.sh

@@ -1,6 +1,8 @@
 #!/bin/sh
 
 test_description='git cat-file filters support'
+
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'setup ' '