[PATCH 1/2] [GSOC] cat-file: fix --batch report changed-type bug

From: ZheNing Hu via GitGitGadget <gitgitgadget@gmail.com>
Date: Jun 1, 2021, 14:35 UTC
Message-ID: <495cd90dbaf43e957d03edd2fdc7449b39eee53a.1622558157.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.967.git.1622558157.gitgitgadget@gmail.com>

From: ZheNing Hu <adlternative@gmail.com>

When `--batch` used with `--batch-all-objects`, with some format atoms like %(objectname), %(rest) or even no atoms may cause Git exit and report "object xxx changed type!?".

E.g. `git cat-file --batch="batman" --batch-all-objects`

This is because we did not get the object type through oid_object_info_extended(), it's composed of two situations:

1. Since object_info is empty, skip_object_info is
set to true, We skipped collecting the object type.

2. The formatting atom like %(objectname) does not require
oid_object_info_extended() to collect object types.

The correct way to deal with it is to swap the order of setting skip_object_info and setting typep. This will ensure that we must get the type of the object when using --batch.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: ZheNing Hu <adlternative@gmail.com>
---
 builtin/cat-file.c  | 13 +++++++------
 t/t1006-cat-file.sh | 19 +++++++++++++++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 5ebf13359e83..02461bb5ea6f 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -512,12 +512,6 @@ static int batch_objects(struct batch_options *opt)
 	if (opt->cmdmode)
 		data.split_on_whitespace = 1;
 
-	if (opt->all_objects) {
-		struct object_info empty = OBJECT_INFO_INIT;
-		if (!memcmp(&data.info, &empty, sizeof(empty)))
-			data.skip_object_info = 1;
-	}
-
 	/*
 	 * If we are printing out the object, then always fill in the type,
 	 * since we will want to decide whether or not to stream.
@@ -525,6 +519,13 @@ static int batch_objects(struct batch_options *opt)
 	if (opt->print_contents)
 		data.info.typep = &data.type;
 
+	if (opt->all_objects) {
+		struct object_info empty = OBJECT_INFO_INIT;
+
+		if (!memcmp(&data.info, &empty, sizeof(empty)))
+			data.skip_object_info = 1;
+	}
+
 	if (opt->all_objects) {
 		struct object_cb_data cb;
 
diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index 5d2dc99b74ad..1502a27142ba 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -586,4 +586,23 @@ test_expect_success 'cat-file --unordered works' '
 	test_cmp expect actual
 '
 
+test_expect_success 'cat-file --batch="%(objectname)" with --batch-all-objects will work' '
+	git -C all-two cat-file --batch-all-objects --batch-check="%(objectname)" >objects &&
+	git -C all-two cat-file --batch="%(objectname)" <objects >expect &&
+	git -C all-two cat-file --batch-all-objects --batch="%(objectname)" >actual &&
+	cmp expect actual
+'
+
+test_expect_success 'cat-file --batch="%(rest)" with --batch-all-objects will work' '
+	git -C all-two cat-file --batch="%(rest)" <objects >expect &&
+	git -C all-two cat-file --batch-all-objects --batch="%(rest)" >actual &&
+	cmp expect actual
+'
+
+test_expect_success 'cat-file --batch="batman" with --batch-all-objects will work' '
+	git -C all-two cat-file --batch="batman" <objects >expect &&
+	git -C all-two cat-file --batch-all-objects --batch="batman" >actual &&
+	cmp expect actual
+'
+
 test_done

-- 
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