From: Marc Branchaud Date: Fri, 24 Apr 2026 17:42:46 GMT Subject: Re: [PATCH] checkout: add --fetch to fetch remote before resolving start-point Message-ID: <42a620db-6110-4894-97fb-8e49ec577817@gmail.com> In-Reply-To: On 2026-04-24 04:03, Harald Nordgren via GitGitGadget wrote: > From: Harald Nordgren > > Add a --fetch option to git checkout and git switch, plus a > checkout.autoFetch config to enable it by default. When set and the > start-point argument names a configured remote (either bare, like > "origin", or prefixed, like "origin/foo"), fetch that remote before > resolving the ref. Aborts the checkout if the fetch fails. Why tie the behaviour to the nature of the start-point? That seems over-designed and prone to tripping people up. Are you trying to cater to users who have multiple remotes? I can imagine people who just want to do a checkout of anything after fetching -- maybe they want to checkout a new tag, or some other detached HEAD, or just an already-existing local branch. They see that checkout has this nifty --fetch option so they think they can combine git fetch; git checkout into a single command ... but no, only if they checkout something in a remote's namespace. I don't personally feel the need for this new option, but I think you'll have a much easier time implementing and maintaining it if you just make --fetch do a plain fetch without caring about what the starting-point is. M. > Signed-off-by: Harald Nordgren > --- > checkout: add --fetch to fetch remote before resolving start-point > > A workflow I run several times a day looks like: > > git fetch origin > git checkout -b new_branch origin/some-branch > > > The first command exists purely to make the second one see an up-to-date > view of the remote. If I forget it, origin/some-branch points at a stale > commit, and I end up creating a local branch from the wrong starting > point. > > This series teaches git checkout (and git switch) a new --fetch flag > that folds the two steps into one: > > git checkout --fetch -b new_branch origin/some-branch > > > When the start-point argument names a configured remote — either bare > (origin, which resolves to the remote's default branch) or in / form — > git fetch is run before the start-point is resolved. If the fetch fails, > the checkout aborts and no local branch is created. > > A new checkout.autoFetch config option enables the same behavior by > default, for users who always want it. > > Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2281%2FHaraldNordgren%2Fcheckout-fetch-start-point-v1 > Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2281/HaraldNordgren/checkout-fetch-start-point-v1 > Pull-Request: https://github.com/git/git/pull/2281 > > builtin/checkout.c | 48 ++++++++++++++++++++++++++++++++++++++-- > t/t7201-co.sh | 51 +++++++++++++++++++++++++++++++++++++++++++ > t/t9902-completion.sh | 1 + > 3 files changed, 98 insertions(+), 2 deletions(-) > > diff --git a/builtin/checkout.c b/builtin/checkout.c > index e031e61886..c8fbc4923b 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 auto_fetch; > int discard_changes; > int accept_ref; > int accept_pathspec; > @@ -112,6 +115,34 @@ 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); > + cmd.git_cmd = 1; > + free(remote_name); > + if (run_command(&cmd)) > + die(_("failed to fetch start-point '%s'"), arg); > +} > + > static void branch_info_release(struct branch_info *info) > { > free(info->name); > @@ -1237,6 +1268,10 @@ static int git_checkout_config(const char *var, const char *value, > opts->dwim_new_local_branch = git_config_bool(var, value); > return 0; > } > + if (!strcmp(var, "checkout.autofetch")) { > + opts->auto_fetch = git_config_bool(var, value); > + return 0; > + } > > if (starts_with(var, "submodule.")) > return git_default_submodule_config(var, value, NULL); > @@ -1942,8 +1977,13 @@ 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->auto_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) { > @@ -2052,6 +2092,8 @@ int cmd_checkout(int argc, > OPT_BOOL(0, "overlay", &opts.overlay_mode, N_("use overlay mode (default)")), > OPT_BOOL(0, "auto-advance", &opts.auto_advance, > N_("auto advance to the next file when selecting hunks interactively")), > + OPT_BOOL(0, "fetch", &opts.auto_fetch, > + N_("fetch from the remote first if is a remote-tracking ref")), > OPT_END() > }; > > @@ -2102,6 +2144,8 @@ int cmd_switch(int argc, > N_("second guess 'git switch '")), > OPT_BOOL(0, "discard-changes", &opts.discard_changes, > N_("throw away local modifications")), > + OPT_BOOL(0, "fetch", &opts.auto_fetch, > + N_("fetch from the remote first if is a remote-tracking ref")), > OPT_END() > }; > > diff --git a/t/t7201-co.sh b/t/t7201-co.sh > index 9bcf7c0b40..60ddebd9c3 100755 > --- a/t/t7201-co.sh > +++ b/t/t7201-co.sh > @@ -801,4 +801,55 @@ test_expect_success 'tracking info copied with autoSetupMerge=inherit' ' > test_cmp_config "" --default "" branch.main2.merge > ' > > +test_expect_success 'setup upstream for --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 --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 --fetch -b local_new fetch_upstream/fetch_new && > + test_cmp_rev refs/remotes/fetch_upstream/fetch_new HEAD > +' > + > +test_expect_success 'checkout --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 --fetch -b local_from_remote fetch_upstream && > + git rev-parse --verify refs/remotes/fetch_upstream/fetch_new2 > +' > + > +test_expect_success 'checkout --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 --fetch -b bogus fetch_upstream/does_not_exist && > + test_must_fail git rev-parse --verify refs/heads/bogus > +' > + > +test_expect_success 'checkout.autoFetch=true enables fetching without --fetch' ' > + git checkout main && > + git -C fetch_upstream checkout -b fetch_cfg && > + test_commit -C fetch_upstream u_cfg && > + test_must_fail git rev-parse --verify refs/remotes/fetch_upstream/fetch_cfg && > + git -c checkout.autoFetch=true checkout -b local_cfg fetch_upstream/fetch_cfg && > + test_cmp_rev refs/remotes/fetch_upstream/fetch_cfg HEAD > +' > + > +test_expect_success 'switch --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 --fetch -c local_switch fetch_upstream/fetch_switch && > + test_cmp_rev refs/remotes/fetch_upstream/fetch_switch HEAD > +' > + > test_done > diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh > index 2f9a597ec7..dc1d63669f 100755 > --- a/t/t9902-completion.sh > +++ b/t/t9902-completion.sh > @@ -2602,6 +2602,7 @@ test_expect_success 'double dash "git checkout"' ' > --ignore-other-worktrees Z > --recurse-submodules Z > --auto-advance Z > + --fetch Z > --progress Z > --guess Z > --no-guess Z > > base-commit: 94f057755b7941b321fd11fec1b2e3ca5313a4e0