shallow: fix relative deepen on non-shallow repositories

The commit "3ef68ff40e (shallow: handling fetch relative-deepen, 2026-02-15)" introduced a bug where using --deepen=<n> on a non- shallow repository incorrectly treated the value as an absolute depth, resulting in a shallow fetch and truncated history. This patch prevents any modification when a relative deepen is requested on a non-shallow repository. A test is added to ensure that history is not changed when --deepen is used on a non-shallow repository. Reported-by: Owen Stephens <owen@owenstephens.co.uk> Signed-off-by: Samo Pogačnik <samo_pogacnik@t-2.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Samo Pogačnik committed May 11, 2026 at 21:20 UTC 2431f5e0e5cd415a3ab1bddb435b692536cc95e8
2 files changed +15 -1
shallow.c
+5 -1
index a8ad92e303..610ff3d13b 100644 --- a/shallow.c +++ b/shallow.c @@ -245,7 +245,11 @@ struct commit_list *get_shallow_commits(struct object_array *heads, int depth, int shallow_flag, int not_shallow_flag) { if (shallows && deepen_relative) { - depth += get_shallows_depth(heads, shallows); + int cur_shallow_depth = get_shallows_depth(heads, shallows); + if (cur_shallow_depth) + depth += cur_shallow_depth; + else + return NULL; } return get_shallows_or_depth(heads, NULL, NULL, depth, shallow_flag, not_shallow_flag);
t/t5537-fetch-shallow.sh
+10
index 6588ce6226..9982dd2aa6 100755 --- a/t/t5537-fetch-shallow.sh +++ b/t/t5537-fetch-shallow.sh @@ -251,6 +251,16 @@ test_expect_success '.git/shallow is edited by repack' ' origin "+refs/heads/*:refs/remotes/origin/*" ' +test_expect_success 'fetch --deepen does not truncate' ' + git clone --no-local .git full-clone && + git -C full-clone rev-parse --is-shallow-repository >expect && + git -C full-clone log --oneline >>expect && + git -C full-clone fetch --deepen=1 && + git -C full-clone rev-parse --is-shallow-repository >actual && + git -C full-clone log --oneline >>actual && + test_cmp expect actual +' + . "$TEST_DIRECTORY"/lib-httpd.sh start_httpd