[PATCH v4 7/7] submodule: trace adding submodule ODB as alternate

From: Jonathan Tan <jonathantanmy@google.com>
Date: Oct 8, 2021, 21:08 UTC
Message-ID: <8922bf48a2fcecfba0030c66f5ea7204b2600181.1633727270.git.jonathantanmy@google.com>
In-Reply-To: <cover.1633727270.git.jonathantanmy@google.com>

Submodule ODBs are never added as alternates during the execution of the test suite, but there may be a rare interaction that the test suite does not have coverage of. Add a trace message when this happens, so that users who trace their commands can notice such occurrences.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 submodule.c | 2 ++
 t/README    | 7 ++-----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/submodule.c b/submodule.c
index 4bf552b0e5..61575e5a56 100644
--- a/submodule.c
+++ b/submodule.c
@@ -201,6 +201,8 @@ int register_all_submodule_odb_as_alternates(void)
 		add_to_alternates_memory(added_submodule_odb_paths.items[i].string);
 	if (ret) {
 		string_list_clear(&added_submodule_odb_paths, 0);
+		trace2_data_intmax("submodule", the_repository,
+				   "register_all_submodule_odb_as_alternates/registered", ret);
 		if (git_env_bool("GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB", 0))
 			BUG("register_all_submodule_odb_as_alternates() called");
 	}
diff --git a/t/README b/t/README
index 51065d0800..b677caaf68 100644
--- a/t/README
+++ b/t/README
@@ -456,11 +456,8 @@ GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB=<boolean>, when true, makes
 registering submodule ODBs as alternates a fatal action. Support for
 this environment variable can be removed once the migration to
 explicitly providing repositories when accessing submodule objects is
-complete (in which case we might want to replace this with a trace2
-call so that users can make it visible if accessing submodule objects
-without an explicit repository still happens) or needs to be abandoned
-for whatever reason (in which case the migrated codepaths still retain
-their performance benefits).
+complete or needs to be abandoned for whatever reason (in which case the
+migrated codepaths still retain their performance benefits).
 
 Naming Tests
 ------------

-- 
2.33.0.882.g93a45727a2-goog