submodule: do not pass null OID to setup_revisions

If "git pull --recurse-submodules --rebase" is invoked when the current
branch and its corresponding remote-tracking branch have no merge base,
a "bad object" fatal error occurs. This issue was introduced with commit
a6d7eb2c7a ("pull: optionally rebase submodules (remote submodule
changes only)", 2017-06-23), which also introduced this feature.

This is because cmd_pull() in builtin/pull.c thus invokes
submodule_touches_in_range() with a null OID as the first parameter.
Ensure that this case works, and document what happens in this case.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/submodule.c b/submodule.c
index 12a2503fda7df9060d858bd572ea106e3141b083..db8bd4a0797be576869bdd741c9e85db5b34c031 100644 (file)
--- a/submodule.c
+++ b/submodule.c
@@ -1166,8 +1166,10 @@ int submodule_touches_in_range(struct object_id *excl_oid,
 
        argv_array_push(&args, "--"); /* args[0] program name */
        argv_array_push(&args, oid_to_hex(incl_oid));
-       argv_array_push(&args, "--not");
-       argv_array_push(&args, oid_to_hex(excl_oid));
+       if (!is_null_oid(excl_oid)) {
+               argv_array_push(&args, "--not");
+               argv_array_push(&args, oid_to_hex(excl_oid));
+       }
 
        collect_changed_submodules(&subs, &args);
        ret = subs.nr;

diff --git a/submodule.h b/submodule.h
index 9589f131273d4f04605c8dbf7dcce05aaea606ad..0189b3ebdeedf4eb00f61bf85a60cae40588bae5 100644 (file)
--- a/submodule.h
+++ b/submodule.h
@@ -94,7 +94,10 @@ extern int merge_submodule(struct object_id *result, const char *path,
                           const struct object_id *a,
                           const struct object_id *b, int search);
 
-/* Checks if there are submodule changes in a..b. */
+/*
+ * Checks if there are submodule changes in a..b. If a is the null OID,
+ * checks b and all its ancestors instead.
+ */
 extern int submodule_touches_in_range(struct object_id *a,
                                      struct object_id *b);
 extern int find_unpushed_submodules(struct oid_array *commits,

diff --git a/t/t5572-pull-submodule.sh b/t/t5572-pull-submodule.sh
index 321bd37deb3d32027c18f8184a9ad46aec9c96c7..f916729a12b24b75184144c2eaa9abdbf1c12639 100755 (executable)
--- a/t/t5572-pull-submodule.sh
+++ b/t/t5572-pull-submodule.sh
@@ -132,4 +132,25 @@ test_expect_success 'pull rebase recursing fails with conflicts' '
        test_i18ngrep "locally recorded submodule modifications" err
 '
 
+test_expect_success 'branch has no merge base with remote-tracking counterpart' '
+       rm -rf parent child &&
+
+       test_create_repo a-submodule &&
+       test_commit -C a-submodule foo &&
+
+       test_create_repo parent &&
+       git -C parent submodule add "$(pwd)/a-submodule" &&
+       git -C parent commit -m foo &&
+
+       git clone parent child &&
+
+       # Reset master so that it has no merge base with
+       # refs/remotes/origin/master.
+       OTHER=$(git -C child commit-tree -m bar \
+               $(git -C child rev-parse HEAD^{tree})) &&
+       git -C child reset --hard "$OTHER" &&
+
+       git -C child pull --recurse-submodules --rebase
+'
+
 test_done