cmd_fetch() performs certain tasks with the assumption that objects are
fetched, but `git fetch --negotiate-only` does not fetch objects, as its
name implies. This is results in behavior that is unnecessary at best,
and incorrect at worst:
* Submodules are updated if enabled by recurse.submodules=true, but
negotiation fetch doesn't actually update the repo, so this doesn't
make sense (introduced in [1]).
* Commit graphs will be written if enabled by
fetch.writeCommitGraph=true. But according to
Documentation/config/fetch.txt [2], this should only be done if a
pack-file is downloaded.
* gc is run, but according to [3], we only do this because we expect
`git fetch` to introduce objects.
Make `git fetch --negotiate-only` handle these tasks more rigorously by
doing the following:
* Make cmd_fetch() return early if we know for certain that objects will
not be fetched
* Disable submodule recursion and die() if a user explicitly asks for it
[1] 7dce19d374 (fetch/pull: Add the --recurse-submodules option, 2010-11-12)
[2] 50f26bd035 (fetch: add fetch.writeCommitGraph config setting, 2019-09-02)
[3] 131b8fcbfb (fetch: run gc --auto after fetching, 2013-01-26)
Changes since v2:
* added a prepatory patch that introduces a "goto cleanup"
* drop an unnecessary line move (as suggested by Junio)
* check for user-given --recurse-submodules and die() (as suggested by
Jonathan and Junio)
* update --negotiate-only's documentation
Changes since v1:
* added more context to commit message
* added a NEEDSWORK comment
Glen Choo (3):
builtin/fetch: use goto cleanup in cmd_fetch()
builtin/fetch: skip unnecessary tasks when using --negotiate-only
builtin/fetch: die on --negotiate-only and --recurse-submodules
Documentation/fetch-options.txt | 1 +
builtin/fetch.c | 41 +++++++++++++++++++++++++++++----
t/t5516-fetch-push.sh | 12 ++++++++++
t/t5702-protocol-v2.sh | 17 ++++++++++++++
4 files changed, 67 insertions(+), 4 deletions(-)
Range-diff against v2:
-: ---------- > 1: 97e2cba633 builtin/fetch: use goto cleanup in cmd_fetch()
1: 9d18270a41 ! 2: 3a3a04b649 builtin/fetch: skip unnecessary tasks when using --negotiate-only
@@ Commit message
return early whenever objects are not fetched, but for now this only
considers --negotiate-only.
+ A similar optimization would be to skip irrelevant tasks in `git fetch
+ --dry-run`. This optimization was not done in this commit because a dry
+ run will actually fetch objects; we'd presumably still want to recurse
+ into submodules and run gc.
+
[1] 7dce19d374 (fetch/pull: Add the --recurse-submodules option, 2010-11-12)
[2] 50f26bd035 (fetch: add fetch.writeCommitGraph config setting, 2019-09-02)
[3] 131b8fcbfb (fetch: run gc --auto after fetching, 2013-01-26)
@@ builtin/fetch.c: int cmd_fetch(int argc, const char **argv, const char *prefix)
+ * submodules, so there is no need to read .gitmodules.
+ */
+ recurse_submodules = RECURSE_SUBMODULES_OFF;
-+ if (!negotiation_tip.nr)
-+ die(_("--negotiate-only needs one or more --negotiate-tip=*"));
+ }
+
if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
int *sfjc = submodule_fetch_jobs_config == -1
? &submodule_fetch_jobs_config : NULL;
-@@ builtin/fetch.c: int cmd_fetch(int argc, const char **argv, const char *prefix)
- fetch_config_from_gitmodules(sfjc, rs);
- }
-
-- if (negotiate_only && !negotiation_tip.nr)
-- die(_("--negotiate-only needs one or more --negotiate-tip=*"));
--
- if (deepen_relative) {
- if (deepen_relative < 0)
- die(_("Negative depth in --deepen is not supported"));
@@ builtin/fetch.c: int cmd_fetch(int argc, const char **argv, const char *prefix)
result = fetch_multiple(&list, max_children);
}
-+ string_list_clear(&list, 0);
-+
+ /*
+ * Skip irrelevant tasks because we know objects were not
+ * fetched.
@@ builtin/fetch.c: int cmd_fetch(int argc, const char **argv, const char *prefix)
+ * of them.
+ */
+ if (negotiate_only)
-+ return result;
++ goto cleanup;
+
if (!result && (recurse_submodules != RECURSE_SUBMODULES_OFF)) {
struct strvec options = STRVEC_INIT;
int max_children = max_jobs;
-@@ builtin/fetch.c: int cmd_fetch(int argc, const char **argv, const char *prefix)
- strvec_clear(&options);
- }
-
-- string_list_clear(&list, 0);
--
- prepare_repo_settings(the_repository);
- if (fetch_write_commit_graph > 0 ||
- (fetch_write_commit_graph < 0 &&
## t/t5516-fetch-push.sh ##
@@ t/t5516-fetch-push.sh: test_expect_success 'push with negotiation proceeds anyway even if negotiation f
-: ---------- > 3: 97792b5214 builtin/fetch: die on --negotiate-only and --recurse-submodules
base-commit: abe6bb3905392d5eb6b01fa6e54d7e784e0522aa
--
2.33.GIT
