Extend checkout --track with a fetch mode to refresh start-point.
Changes in v15:
* Reword commit message to lead with motivation.
* Drop RESOLVE_REF_NO_RECURSE so <ns>/HEAD lookup matches what git checkout
does for the same ref. Drop redundant check_refname_format on a ref we
just read. Replace memset with brace initializer. Use refs_ref_exists and
pass NULL for the OID out-params.
* Split the "set HEAD" error onto its own line via die_message and advise,
matching the suggested format.
* Remove 6 redundant tests, replace test $a = $b with test_cmp_rev, and
rename test titles to avoid "namespace".
Changes in v14:
* Handle .h files in a better way.
Changes in v13:
* Create a preparatory commit that exposes find_tracking_remote_for_ref()
and advise_ambiguous_fetch_refspec() from branch.c, so checkout can reuse
the same lookup git branch --track uses.
* Use advise_ambiguous_fetch_refspec() for the "multiple remotes match"
case, so the wording matches git branch --track.
Harald Nordgren (2):
branch: expose helpers for finding the remote owning a tracking ref
checkout: extend --track with a "fetch" mode to refresh start-point
Documentation/git-checkout.adoc | 17 ++-
Documentation/git-switch.adoc | 5 +-
branch.c | 96 +++++++-------
branch.h | 16 +++
builtin/checkout.c | 138 +++++++++++++++++++-
t/t7201-co.sh | 222 ++++++++++++++++++++++++++++++++
6 files changed, 443 insertions(+), 51 deletions(-)
base-commit: ab776a62a78576513ee121424adb19597fbb7613
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2281%2FHaraldNordgren%2Fcheckout-fetch-start-point-v15
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2281/HaraldNordgren/checkout-fetch-start-point-v15
Pull-Request: https://github.com/git/git/pull/2281
Range-diff vs v14:
1: f79689c23d = 1: 8139490c36 branch: expose helpers for finding the remote owning a tracking ref
2: 8518f090b1 ! 2: b7e387f123 checkout: extend --track with a "fetch" mode to refresh start-point
@@ Metadata
## Commit message ##
checkout: extend --track with a "fetch" mode to refresh start-point
- Add a "fetch" mode to the "--track" option of "git checkout" / "git
- switch" that refreshes <start-point> before checking it out:
+ Forking from an existing remote branch without refreshing first often
+ has consequences: you start work that has already been done, or you
+ build on an old version of the code which causes big conflicts later
+ when you pull. The workaround is two commands ("git fetch <remote>
+ <branch> && git checkout -b <topic> <remote>/<branch>"), and when
+ the fetch is skipped the checkout silently starts from a stale tip.
- git checkout -b new_branch --track=fetch origin/some-branch
+ Users may already expect "<remote>/<branch>" to refer to the latest
+ tip on the remote. While this blurs the line between fetch and
+ checkout, git already does this in places where it pays off: "git
+ clone" fetches and checks out, and "git pull" fetches and merges.
- is shorthand for
+ Add a "fetch" mode to "--track" that refreshes <start-point> before
+ checking it out:
- git fetch origin some-branch
- git checkout -b new_branch --track origin/some-branch
+ git checkout -b new_branch --track=fetch origin/some-branch
- Identify the remote whose configured fetch refspec maps to
- <start-point> using find_tracking_remote_for_ref() (the same lookup
- "--track" uses to pick which remote to record in
- branch.<name>.remote), then run "git fetch <remote> <src-ref>" for
- just that ref so other remote-tracking branches are left untouched.
- When <start-point> is a bare <remote> (e.g. "origin"), follow
- refs/remotes/<remote>/HEAD to learn which branch to refresh. If
- "git fetch" fails but the remote-tracking ref already exists locally,
- warn and proceed from the existing tip; otherwise abort.
+ Only the requested branch is fetched so other remote-tracking
+ branches are left untouched. When <start-point> is a bare <remote>
+ (e.g. "origin"), follow refs/remotes/<remote>/HEAD to learn which
+ branch to refresh. If "git fetch" fails but the remote-tracking ref
+ already exists locally, warn and proceed from the existing tip,
+ otherwise abort.
Signed-off-by: Harald Nordgren <haraldnordgren@gmail.com>
@@ builtin/checkout.c: struct branch_info {
+static void fetch_remote_for_start_point(const char *arg, int quiet)
+{
+ struct strbuf dst = STRBUF_INIT;
-+ struct tracking tracking;
++ struct tracking tracking = { 0 };
+ struct string_list tracking_srcs = STRING_LIST_INIT_DUP;
+ struct string_list ambiguous_remotes = STRING_LIST_INIT_DUP;
+ struct child_process cmd = CHILD_PROCESS_INIT;
-+ struct object_id oid;
+ struct remote *named_remote;
+ int bare_ns;
+
@@ builtin/checkout.c: struct branch_info {
+ const char *head_target =
+ refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
+ head_path,
-+ RESOLVE_REF_READING |
-+ RESOLVE_REF_NO_RECURSE,
-+ &oid, NULL);
++ RESOLVE_REF_READING,
++ NULL, NULL);
+ if (head_target &&
+ starts_with(head_target, dst.buf) &&
-+ head_target[dst.len] == '/' &&
-+ !check_refname_format(head_target, 0)) {
++ head_target[dst.len] == '/') {
+ strbuf_reset(&dst);
+ strbuf_addstr(&dst, head_target);
+ bare_ns = 0;
@@ builtin/checkout.c: struct branch_info {
+ free(head_path);
+ }
+
-+ memset(&tracking, 0, sizeof(tracking));
+ tracking.spec.dst = dst.buf;
+ tracking.srcs = &tracking_srcs;
+ find_tracking_remote_for_ref(&tracking, &ambiguous_remotes);
@@ builtin/checkout.c: struct branch_info {
+
+ if (!tracking.matches) {
+ if (bare_ns && named_remote &&
-+ remote_is_configured(named_remote, 1))
-+ die(_("cannot fetch start-point '%s': "
-+ "'refs/remotes/%s/HEAD' is not set; run "
-+ "'git remote set-head %s --auto' to set it"),
-+ arg, arg, arg);
++ remote_is_configured(named_remote, 1)) {
++ int status = die_message(_("cannot fetch start-point '%s' "
++ "because 'refs/remotes/%s/HEAD' "
++ "does not exist."), arg, arg);
++ advise(_("To create it run\n"
++ "\n"
++ " git remote set-head %s --auto\n"), arg);
++ exit(status);
++ }
+ die(_("cannot fetch start-point '%s': no configured remote's "
+ "fetch refspec matches it"), arg);
+ }
@@ builtin/checkout.c: struct branch_info {
+ tracking_srcs.items[0].string, NULL);
+ cmd.git_cmd = 1;
+ if (run_command(&cmd)) {
-+ if (!refs_read_ref(get_main_ref_store(the_repository),
-+ dst.buf, &oid))
++ if (refs_ref_exists(get_main_ref_store(the_repository), dst.buf))
+ warning(_("failed to fetch start-point '%s'; "
+ "using existing '%s'"), arg, dst.buf);
+ else
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ git -C fetch_upstream checkout -b fetch_other &&
+ test_commit -C fetch_upstream u_other_pre &&
+ git fetch fetch_upstream &&
-+ other_before=$(git rev-parse refs/remotes/fetch_upstream/fetch_other) &&
++ git update-ref refs/heads/snapshot_other refs/remotes/fetch_upstream/fetch_other &&
+ git -C fetch_upstream checkout fetch_target &&
+ test_commit -C fetch_upstream u_target_post &&
+ git -C fetch_upstream checkout fetch_other &&
+ test_commit -C fetch_upstream u_other_post &&
+ git checkout --track=fetch -b local_target fetch_upstream/fetch_target &&
+ test_cmp_rev refs/remotes/fetch_upstream/fetch_target HEAD &&
-+ test "$(git rev-parse refs/remotes/fetch_upstream/fetch_other)" = "$other_before"
++ test_cmp_rev refs/remotes/fetch_upstream/fetch_other snapshot_other
+'
+
+test_expect_success 'checkout --track=fetch with bare remote name fetches only <remote>/HEAD target' '
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ git -C fetch_upstream checkout -b fetch_unrelated &&
+ test_commit -C fetch_upstream u_unrelated_pre &&
+ git fetch fetch_upstream fetch_unrelated &&
-+ unrelated_before=$(git rev-parse refs/remotes/fetch_upstream/fetch_unrelated) &&
++ git update-ref refs/heads/snapshot_unrelated \
++ refs/remotes/fetch_upstream/fetch_unrelated &&
+ git -C fetch_upstream checkout main &&
+ test_commit -C fetch_upstream u_main_post &&
+ git -C fetch_upstream checkout fetch_unrelated &&
+ test_commit -C fetch_upstream u_unrelated_post &&
+ git checkout --track=fetch -b local_from_remote fetch_upstream &&
+ test_cmp_rev refs/remotes/fetch_upstream/main HEAD &&
-+ test "$(git rev-parse refs/remotes/fetch_upstream/fetch_unrelated)" = "$unrelated_before"
++ test_cmp_rev refs/remotes/fetch_upstream/fetch_unrelated snapshot_unrelated
+'
+
+test_expect_success 'checkout --track=fetch aborts and does not create branch when no existing ref' '
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_cmp_rev refs/remotes/custom-ns/fetch_refspec HEAD
+'
+
-+test_expect_success 'checkout --track=fetch on namespace bare name follows <ns>/HEAD' '
++test_expect_success 'checkout --track=fetch on bare remote-tracking prefix follows <prefix>/HEAD' '
+ git checkout main &&
+ git remote add fetch_ns ./fetch_upstream &&
+ test_when_finished "git remote remove fetch_ns" &&
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_cmp_config refs/heads/main branch.local_ns.merge
+'
+
-+test_expect_success '--track=fetch on bare hierarchical remote name follows <ns>/HEAD' '
-+ git checkout main &&
-+ git remote add nested/bare ./fetch_upstream &&
-+ test_when_finished "git remote remove nested/bare" &&
-+ test_when_finished "git update-ref -d refs/remotes/nested/bare/HEAD" &&
-+ git fetch nested/bare &&
-+ git symbolic-ref refs/remotes/nested/bare/HEAD \
-+ refs/remotes/nested/bare/main &&
-+ git -C fetch_upstream checkout main &&
-+ test_commit -C fetch_upstream u_nested_bare_post &&
-+ git checkout --track=fetch -b local_nested_bare nested/bare &&
-+ test_cmp_rev refs/remotes/nested/bare/main HEAD
-+'
-+
-+test_expect_success 'checkout --track=fetch handles hierarchical remote name' '
-+ git checkout main &&
-+ git remote add nested/remote ./fetch_upstream &&
-+ test_when_finished "git remote remove nested/remote" &&
-+ git -C fetch_upstream checkout -b fetch_hier &&
-+ test_commit -C fetch_upstream u_hier &&
-+ test_must_fail git rev-parse --verify refs/remotes/nested/remote/fetch_hier &&
-+ git checkout --track=fetch -b local_hier nested/remote/fetch_hier &&
-+ test_cmp_rev refs/remotes/nested/remote/fetch_hier HEAD
-+'
-+
+test_expect_success 'checkout --track=fetch dies on bare remote name with no <ns>/HEAD' '
+ git checkout main &&
+ git remote add fetch_nohead ./fetch_upstream &&
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_must_fail git rev-parse --verify refs/heads/local_unknown
+'
+
-+test_expect_success 'checkout --track=fetch rejects <ns>/HEAD pointing outside namespace' '
++test_expect_success 'checkout --track=fetch rejects <ns>/HEAD pointing outside the tracking prefix' '
+ git checkout main &&
+ git remote add fetch_crossns ./fetch_upstream &&
+ test_when_finished "git remote remove fetch_crossns" &&
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_must_fail git rev-parse --verify refs/heads/local_invalid
+'
+
-+test_expect_success 'checkout --track=fetch,inherit rejects invalid refname components' '
-+ git checkout main &&
-+ test_must_fail git checkout --track=fetch,inherit -b local_invalid \
-+ "foo..bar" 2>err &&
-+ test_grep "valid" err &&
-+ test_must_fail git rev-parse --verify refs/heads/local_invalid
-+'
-+
+test_expect_success 'checkout --track=inherit,direct is rejected' '
+ test_must_fail git checkout --track=inherit,direct -b bad fetch_upstream/fetch_new 2>err &&
+ test_grep "cannot combine" err
+'
+
-+test_expect_success 'checkout --track=direct,inherit is rejected' '
-+ test_must_fail git checkout --track=direct,inherit -b bad fetch_upstream/fetch_new 2>err &&
-+ test_grep "cannot combine" err
-+'
-+
+test_expect_success 'checkout --track=fetch then --track=direct drops fetch (last-one-wins)' '
+ git checkout main &&
+ git -C fetch_upstream checkout -b fetch_lastwin &&
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_lastwin
+'
+
-+test_expect_success 'checkout --track=fetch then --no-track drops fetch' '
-+ git checkout main &&
-+ git -C fetch_upstream checkout -b fetch_notrack &&
-+ test_commit -C fetch_upstream u_notrack &&
-+ test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_notrack &&
-+ test_must_fail git checkout --track=fetch --no-track \
-+ -b local_notrack fetch_upstream/fetch_notrack &&
-+ test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_notrack
-+'
-+
+test_expect_success 'checkout --track=fetch,inherit fetches remote-tracking start-point' '
+ git checkout main &&
+ git -C fetch_upstream checkout -b fetch_inherit &&
@@ t/t7201-co.sh: test_expect_success 'tracking info copied with autoSetupMerge=inh
+ test_cmp_rev refs/remotes/fetch_upstream/fetch_inherit HEAD
+'
+
-+test_expect_success 'checkout --track=fetch,inherit errors when start-point does not map to a remote' '
-+ git checkout main &&
-+ test_must_fail git checkout --track=fetch,inherit -b bad main 2>err &&
-+ test_grep "no configured remote" err &&
-+ test_must_fail git rev-parse --verify refs/heads/bad
-+'
-+
+test_expect_success 'checkout --track=fetch on local start-point errors' '
+ git checkout main &&
+ test_must_fail git checkout --track=fetch -b bad main 2>err &&Harald Nordgren via GitGitGadget <gitgitgadget@gmail.com>