From: Harald Nordgren via GitGitGadget Date: Sun, 03 May 2026 22:31:27 GMT Subject: [PATCH v6] checkout: extend --track with a "fetch" mode to refresh start-point Message-ID: In-Reply-To: From: Harald Nordgren If you want to fork your topic branch from the very latest of the tip of a branch your remote has, you would do: git fetch origin some-branch git checkout -b new_branch --track origin/some-branch Extend the "--track" option of "git checkout" and allow users to write git checkout -b new_branch --track=fetch origin/some-branch to (1) fetch 'some-branch' from the remote 'origin', updating the remote-tracking branch 'origin/some-branch', (2) arrange subsequent 'git pull' on 'new_branch' to interact with 'origin/some-branch' and (3) fork 'new_branch' from it. In the value of the '--track' option, 'fetch' can be combined with the existing 'direct' (default) and 'inherit' modes via a comma-separated list. Examples: git checkout -b new_branch --track=fetch,inherit some_local_branch git switch -c new_branch --track=fetch origin/some-branch When "fetch" is requested and is in / form, run "git fetch " before resolving the ref, so that other remote-tracking branches are left untouched. If is a bare remote name like "origin" (which resolves to that remote's default branch), "git fetch " is run instead, since the target branch is not known up front. Abort the checkout if the fetch fails. Signed-off-by: Harald Nordgren --- checkout: add --fetch to fetch remote before resolving start-point Commit message only, no code/doc/test changes. Restructured the opening around the user-visible workflow before introducing '--track=fetch', reordered all example invocations to ' -b/-c --track[=...] ', dropped the "wrong/stale start-point" and "arbitrary commit" framings, and trimmed the over-explanation of the narrowed fetch. Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2281%2FHaraldNordgren%2Fcheckout-fetch-start-point-v6 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2281/HaraldNordgren/checkout-fetch-start-point-v6 Pull-Request: https://github.com/git/git/pull/2281 Range-diff vs v5: 1: 8ebc2f94b9 ! 1: 1b42c648b9 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 - A common workflow is: + If you want to fork your topic branch from the very latest of the + tip of a branch your remote has, you would do: - git fetch origin + git fetch origin some-branch git checkout -b new_branch --track origin/some-branch - The first command exists so the second sees an up-to-date view of the - remote. If it is forgotten, origin/some-branch points at a stale - commit and the new local branch is created from the wrong start - point. This only matters when the user is setting up tracking and - expects the new branch to start at the freshest tip; for a one-off - checkout of an arbitrary commit there is no reason to "freshen" the - start-point. + Extend the "--track" option of "git checkout" and allow users to + write - Tie the new behavior to --track for that reason: extend its argument - to take a comma-separated list, where "fetch" can be combined with the - existing "direct" (default) and "inherit" modes. Examples: + git checkout -b new_branch --track=fetch origin/some-branch - git checkout --track=fetch -b new_branch origin/some-branch - git checkout --track=fetch,inherit -b new_branch some_local_branch - git switch --track=fetch -c new_branch origin/some-branch + to (1) fetch 'some-branch' from the remote 'origin', updating the + remote-tracking branch 'origin/some-branch', (2) arrange subsequent + 'git pull' on 'new_branch' to interact with 'origin/some-branch' and + (3) fork 'new_branch' from it. + + In the value of the '--track' option, 'fetch' can be combined with + the existing 'direct' (default) and 'inherit' modes via a + comma-separated list. Examples: + + git checkout -b new_branch --track=fetch,inherit some_local_branch + git switch -c new_branch --track=fetch origin/some-branch When "fetch" is requested and is in / - form, run "git fetch " before resolving the ref. This - narrows the fetch to the requested branch so that other - remote-tracking branches are left untouched -- many tools rely on the - stability of remote-tracking refs between explicit fetches. If + form, run "git fetch " before resolving the ref, so + that other remote-tracking branches are left untouched. If is a bare remote name like "origin" (which resolves to that remote's default branch), "git fetch " is run instead, since the target branch is not known up front. Abort the checkout if Documentation/git-checkout.adoc | 10 +++- Documentation/git-switch.adoc | 10 +++- builtin/checkout.c | 85 +++++++++++++++++++++++++++++++-- t/t7201-co.sh | 81 +++++++++++++++++++++++++++++++ 4 files changed, 179 insertions(+), 7 deletions(-) diff --git a/Documentation/git-checkout.adoc b/Documentation/git-checkout.adoc index 43ccf47cf6..3b8292612d 100644 --- a/Documentation/git-checkout.adoc +++ b/Documentation/git-checkout.adoc @@ -158,11 +158,19 @@ of it"). resets __ to the start point instead of failing. `-t`:: -`--track[=(direct|inherit)]`:: +`--track[=(direct|inherit|fetch)[,...]]`:: When creating a new branch, set up "upstream" configuration. See `--track` in linkgit:git-branch[1] for details. As a convenience, --track without -b implies branch creation. + +The argument is a comma-separated list. `direct` (the default) and +`inherit` select the tracking mode. Adding `fetch` requests that the +remote be fetched before __ is resolved, so the new branch +starts from a fresh tip: when __ is in +_/_ form, only that branch is updated; when it is a +bare remote name (e.g. `origin`), the whole remote is fetched. If the +fetch fails, the checkout is aborted. ++ If no `-b` option is given, the name of the new branch will be derived from the remote-tracking branch, by looking at the local part of the refspec configured for the corresponding remote, and then stripping diff --git a/Documentation/git-switch.adoc b/Documentation/git-switch.adoc index 87707e9265..35a03e8a52 100644 --- a/Documentation/git-switch.adoc +++ b/Documentation/git-switch.adoc @@ -154,11 +154,19 @@ should result in deletion of the path). attached to a terminal, regardless of `--quiet`. `-t`:: -`--track[ (direct|inherit)]`:: +`--track[=(direct|inherit|fetch)[,...]]`:: When creating a new branch, set up "upstream" configuration. `-c` is implied. See `--track` in linkgit:git-branch[1] for details. + +The argument is a comma-separated list. `direct` (the default) and +`inherit` select the tracking mode. Adding `fetch` requests that the +remote be fetched before __ is resolved, so the new branch +starts from a fresh tip: when __ is in +_/_ form, only that branch is updated; when it is a +bare remote name (e.g. `origin`), the whole remote is fetched. If the +fetch fails, the switch is aborted. ++ If no `-c` option is given, the name of the new branch will be derived from the remote-tracking branch, by looking at the local part of the refspec configured for the corresponding remote, and then stripping diff --git a/builtin/checkout.c b/builtin/checkout.c index e031e61886..de4d7c00c7 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -30,7 +30,9 @@ #include "repo-settings.h" #include "resolve-undo.h" #include "revision.h" +#include "run-command.h" #include "setup.h" +#include "strvec.h" #include "submodule.h" #include "symlinks.h" #include "trace2.h" @@ -61,6 +63,7 @@ struct checkout_opts { int count_checkout_paths; int overlay_mode; int dwim_new_local_branch; + int fetch; int discard_changes; int accept_ref; int accept_pathspec; @@ -112,6 +115,74 @@ struct branch_info { char *checkout; }; +static void fetch_remote_for_start_point(const char *arg) +{ + const char *slash; + char *remote_name; + struct remote *remote; + struct child_process cmd = CHILD_PROCESS_INIT; + + if (!arg || !*arg) + return; + + slash = strchr(arg, '/'); + if (slash == arg) + return; + remote_name = slash ? xstrndup(arg, slash - arg) : xstrdup(arg); + + remote = remote_get(remote_name); + if (!remote || !remote_is_configured(remote, 1)) { + free(remote_name); + return; + } + + strvec_pushl(&cmd.args, "fetch", remote_name, NULL); + if (slash && slash[1]) + strvec_push(&cmd.args, slash + 1); + cmd.git_cmd = 1; + free(remote_name); + if (run_command(&cmd)) + die(_("failed to fetch start-point '%s'"), arg); +} + +static int parse_opt_checkout_track(const struct option *opt, + const char *arg, int unset) +{ + struct checkout_opts *opts = opt->value; + struct string_list tokens = STRING_LIST_INIT_DUP; + struct string_list_item *item; + int ret = 0; + + if (unset) { + opts->track = BRANCH_TRACK_NEVER; + opts->fetch = 0; + return 0; + } + + opts->track = BRANCH_TRACK_EXPLICIT; + if (!arg) + return 0; + + string_list_split(&tokens, arg, ",", -1); + for_each_string_list_item(item, &tokens) { + if (!strcmp(item->string, "fetch")) { + opts->fetch = 1; + } else if (!strcmp(item->string, "direct")) { + opts->track = BRANCH_TRACK_EXPLICIT; + } else if (!strcmp(item->string, "inherit")) { + opts->track = BRANCH_TRACK_INHERIT; + } else { + ret = error(_("option `%s' expects \"%s\", \"%s\", " + "or \"%s\""), + "--track", "direct", "inherit", "fetch"); + break; + } + } + + string_list_clear(&tokens, 0); + return ret; +} + static void branch_info_release(struct branch_info *info) { free(info->name); @@ -1237,7 +1308,6 @@ static int git_checkout_config(const char *var, const char *value, opts->dwim_new_local_branch = git_config_bool(var, value); return 0; } - if (starts_with(var, "submodule.")) return git_default_submodule_config(var, value, NULL); @@ -1734,10 +1804,10 @@ static struct option *add_common_switch_branch_options( { struct option options[] = { OPT_BOOL('d', "detach", &opts->force_detach, N_("detach HEAD at named commit")), - OPT_CALLBACK_F('t', "track", &opts->track, "(direct|inherit)", + OPT_CALLBACK_F('t', "track", opts, "(direct|inherit|fetch)[,...]", N_("set branch tracking configuration"), PARSE_OPT_OPTARG, - parse_opt_tracking_mode), + parse_opt_checkout_track), OPT__FORCE(&opts->force, N_("force checkout (throw away local modifications)"), PARSE_OPT_NOCOMPLETE), OPT_STRING(0, "orphan", &opts->new_orphan_branch, N_("new-branch"), N_("new unborn branch")), @@ -1942,8 +2012,13 @@ static int checkout_main(int argc, const char **argv, const char *prefix, opts->dwim_new_local_branch && opts->track == BRANCH_TRACK_UNSPECIFIED && !opts->new_branch; - int n = parse_branchname_arg(argc, argv, dwim_ok, which_command, - &new_branch_info, opts, &rev); + int n; + + if (opts->fetch) + fetch_remote_for_start_point(argv[0]); + + n = parse_branchname_arg(argc, argv, dwim_ok, which_command, + &new_branch_info, opts, &rev); argv += n; argc -= n; } else if (!opts->accept_ref && opts->from_treeish) { diff --git a/t/t7201-co.sh b/t/t7201-co.sh index 9bcf7c0b40..39236dca12 100755 --- a/t/t7201-co.sh +++ b/t/t7201-co.sh @@ -801,4 +801,85 @@ test_expect_success 'tracking info copied with autoSetupMerge=inherit' ' test_cmp_config "" --default "" branch.main2.merge ' +test_expect_success 'setup upstream for --track=fetch tests' ' + git checkout main && + git init fetch_upstream && + test_commit -C fetch_upstream u_main && + git remote add fetch_upstream fetch_upstream && + git fetch fetch_upstream && + git -C fetch_upstream checkout -b fetch_new && + test_commit -C fetch_upstream u_new +' + +test_expect_success 'checkout --track=fetch -b picks up branch created upstream after clone' ' + git checkout main && + test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_new && + git checkout --track=fetch -b local_new fetch_upstream/fetch_new && + test_cmp_rev refs/remotes/fetch_upstream/fetch_new HEAD && + test_cmp_config fetch_upstream branch.local_new.remote && + test_cmp_config refs/heads/fetch_new branch.local_new.merge +' + +test_expect_success 'checkout --track=fetch / leaves other tracking branches untouched' ' + git checkout main && + git -C fetch_upstream checkout -b fetch_target && + test_commit -C fetch_upstream u_target_pre && + git -C fetch_upstream checkout -b fetch_other && + test_commit -C fetch_upstream u_other_pre && + git fetch fetch_upstream && + other_before=$(git rev-parse refs/remotes/fetch_upstream/fetch_other) && + git -C fetch_upstream checkout fetch_target && + test_commit -C fetch_upstream u_target_post && + git -C fetch_upstream checkout fetch_other && + test_commit -C fetch_upstream u_other_post && + git checkout --track=fetch -b local_target fetch_upstream/fetch_target && + test_cmp_rev refs/remotes/fetch_upstream/fetch_target HEAD && + test "$(git rev-parse refs/remotes/fetch_upstream/fetch_other)" = "$other_before" +' + +test_expect_success 'checkout --track=fetch with bare remote name fetches the remote' ' + git checkout main && + git -C fetch_upstream checkout -b fetch_new2 && + test_commit -C fetch_upstream u_new2 && + test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_new2 && + git checkout --track=fetch -b local_from_remote fetch_upstream && + git rev-parse --verify refs/remotes/fetch_upstream/fetch_new2 +' + +test_expect_success 'checkout --track=fetch aborts and does not create branch on fetch failure' ' + git checkout main && + test_might_fail git branch -D bogus && + test_must_fail git checkout --track=fetch -b bogus fetch_upstream/does_not_exist && + test_must_fail git rev-parse --verify refs/heads/bogus +' + +test_expect_success 'checkout --track=fetch,inherit fetches and inherits' ' + git checkout main && + git -C fetch_upstream checkout -b fetch_inherit && + test_commit -C fetch_upstream u_inherit && + git fetch fetch_upstream fetch_inherit && + git checkout -b base_inherit fetch_upstream/fetch_inherit && + test_commit -C fetch_upstream u_inherit2 && + git checkout main && + git checkout --track=fetch,inherit -b local_inherit base_inherit && + test_cmp_rev refs/remotes/fetch_upstream/fetch_inherit HEAD && + test_cmp_config fetch_upstream branch.local_inherit.remote && + test_cmp_config refs/heads/fetch_inherit branch.local_inherit.merge +' + +test_expect_success 'checkout --track=bogus reports an error' ' + git checkout main && + test_must_fail git checkout --track=bogus -b bogus_branch fetch_upstream/fetch_new 2>err && + test_grep "expects" err +' + +test_expect_success 'switch --track=fetch -c picks up branch created upstream after clone' ' + git checkout main && + git -C fetch_upstream checkout -b fetch_switch && + test_commit -C fetch_upstream u_switch && + test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_switch && + git switch --track=fetch -c local_switch fetch_upstream/fetch_switch && + test_cmp_rev refs/remotes/fetch_upstream/fetch_switch HEAD +' + test_done base-commit: 94f057755b7941b321fd11fec1b2e3ca5313a4e0 -- gitgitgadget