[PATCH v4 1/6] merge-tree: fail with a non-zero exit code on missing tree objects

Johannes Schindelin via GitGitGadget
2024-02-23T08:34:30Z

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(-)

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