diff mbox series

[v3,1/5] merge-tree: fail with a non-zero exit code on missing tree objects

Message ID 11b9cd8c5da5e6792ce940ea29d2e93e57731555.1708612605.git.gitgitgadget@gmail.com (mailing list archive)
State Superseded
Headers show
Series merge-tree: handle missing objects correctly | expand

Commit Message

Johannes Schindelin Feb. 22, 2024, 2:36 p.m. UTC 
From: Johannes Schindelin <johannes.schindelin@gmx.de>

When `git merge-tree` encounters a missing tree object, it should error
out and not continue quietly as if nothing had happened.

However, as of time of writing, `git merge-tree` _does_ continue, and
then offers the empty tree as result.

Let's fix this.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 merge-ort.c                      |  7 ++++---
 t/t4301-merge-tree-write-tree.sh | 11 +++++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

Comments

Junio C Hamano Feb. 22, 2024, 5:13 p.m. UTC | #1 
"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> -	parse_tree(merge_base);
> -	parse_tree(side1);
> -	parse_tree(side2);
> +	if (parse_tree(merge_base) < 0 ||
> +	    parse_tree(side1) < 0 ||
> +	    parse_tree(side2) < 0)
> +		return -1;

Obviously good.

> diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
> index 7d0fa74da74..908c9b540c8 100755
> --- a/t/t4301-merge-tree-write-tree.sh
> +++ b/t/t4301-merge-tree-write-tree.sh
> @@ -951,4 +951,15 @@ test_expect_success '--merge-base with tree OIDs' '
>  	test_cmp with-commits with-trees
>  '
>  
> +test_expect_success 'error out on missing tree objects' '
> +	git init --bare missing-tree.git &&
> +	git rev-list side3 >list &&
> +	git rev-parse side3^: >>list &&
> +	git pack-objects missing-tree.git/objects/pack/side3-tree-is-missing <list &&
> +	side3=$(git rev-parse side3) &&
> +	test_must_fail git --git-dir=missing-tree.git merge-tree $side3^ $side3 >actual 2>err &&
> +	test_grep "Could not read $(git rev-parse $side3:)" err &&
> +	test_must_be_empty actual
> +'

I very much like the way this test emulates an operation in a
repository that lack certaion objects so cleanly, and wish we
had used this pattern instead of poking at loose object files
in hundreds of existing tests (#leftoverbits obviously).

It also justifies why a silent "return -1" in the patch is
sufficient ;-)

Thanks.
diff mbox series

Patch

diff --git a/merge-ort.c b/merge-ort.c
index 6491070d965..c37fc035f13 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -1659,9 +1659,10 @@  static int collect_merge_info(struct merge_options *opt,
 	info.data = opt;
 	info.show_all_errors = 1;
 
-	parse_tree(merge_base);
-	parse_tree(side1);
-	parse_tree(side2);
+	if (parse_tree(merge_base) < 0 ||
+	    parse_tree(side1) < 0 ||
+	    parse_tree(side2) < 0)
+		return -1;
 	init_tree_desc(t + 0, merge_base->buffer, merge_base->size);
 	init_tree_desc(t + 1, side1->buffer, side1->size);
 	init_tree_desc(t + 2, side2->buffer, side2->size);
diff --git a/t/t4301-merge-tree-write-tree.sh b/t/t4301-merge-tree-write-tree.sh
index 7d0fa74da74..908c9b540c8 100755
--- a/t/t4301-merge-tree-write-tree.sh
+++ b/t/t4301-merge-tree-write-tree.sh
@@ -951,4 +951,15 @@  test_expect_success '--merge-base with tree OIDs' '
 	test_cmp with-commits with-trees
 '
 
+test_expect_success 'error out on missing tree objects' '
+	git init --bare missing-tree.git &&
+	git rev-list side3 >list &&
+	git rev-parse side3^: >>list &&
+	git pack-objects missing-tree.git/objects/pack/side3-tree-is-missing <list &&
+	side3=$(git rev-parse side3) &&
+	test_must_fail git --git-dir=missing-tree.git merge-tree $side3^ $side3 >actual 2>err &&
+	test_grep "Could not read $(git rev-parse $side3:)" err &&
+	test_must_be_empty actual
+'
+
 test_done