From e3f7d885209e6cf9487bea296bc81df43f3758db Mon Sep 17 00:00:00 2001 From: Yoichi NAKAYAMA Date: Thu, 20 Aug 2026 20:20:22 +0900 Subject: [PATCH 1/3] checkout: extract function to display advice for ambiguous remotes Signed-off-by: Yoichi NAKAYAMA --- builtin/checkout.c | 62 ++++++++++++++++++++++++---------------------- 1 file changed, 33 insertions(+), 29 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 55e3a89a852712..650eda735fc526 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -1343,6 +1343,34 @@ enum checkout_command { CHECKOUT_RESTORE = 3, }; +static void advice_disambiguating_remotes(enum checkout_command which_command) +{ + const char *cmdname; + + switch (which_command) { + case CHECKOUT_CHECKOUT: + cmdname = "checkout"; + break; + case CHECKOUT_SWITCH: + cmdname = "switch"; + break; + default: + BUG("command <%d> should not reach parse_remote_branch", + which_command); + break; + } + + advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n" + "you can do so by fully qualifying the name with the --track option:\n" + "\n" + " git %s --track origin/\n" + "\n" + "If you'd like to always have checkouts of an ambiguous prefer\n" + "one remote, e.g. the 'origin' remote, consider setting\n" + "checkout.defaultRemote=origin in your config."), + cmdname); +} + static char *parse_remote_branch(const char *arg, struct object_id *rev, int could_be_checkout_paths, @@ -1358,35 +1386,11 @@ static char *parse_remote_branch(const char *arg, } if (!remote && num_matches > 1) { - if (advice_enabled(ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME)) { - const char *cmdname; - - switch (which_command) { - case CHECKOUT_CHECKOUT: - cmdname = "checkout"; - break; - case CHECKOUT_SWITCH: - cmdname = "switch"; - break; - default: - BUG("command <%d> should not reach parse_remote_branch", - which_command); - break; - } - - advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n" - "you can do so by fully qualifying the name with the --track option:\n" - "\n" - " git %s --track origin/\n" - "\n" - "If you'd like to always have checkouts of an ambiguous prefer\n" - "one remote, e.g. the 'origin' remote, consider setting\n" - "checkout.defaultRemote=origin in your config."), - cmdname); - } - - die(_("'%s' matched multiple (%d) remote tracking branches"), - arg, num_matches); + if (advice_enabled(ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME)) + advice_disambiguating_remotes(which_command); + + die(_("'%s' matched multiple (%d) remote tracking branches"), + arg, num_matches); } return remote; From 89c0f4d30317ebf7cda884710944e9a6f23d46fe Mon Sep 17 00:00:00 2001 From: Yoichi NAKAYAMA Date: Sat, 22 Aug 2026 08:30:34 +0900 Subject: [PATCH 2/3] checkout: improve message for ambiguous remote branch name When the user runs 'git checkout bar-topic' without specifying a remote, and there is no local branch named bar-topic, we try to guess which remote branch bar-topic refers to, then create a new branch named bar-topic that tracks the remote branch. If multiple remotes have a branch named bar-topic, we cannot determine a single remote. To make it easier to resolve the ambiguity, provide the names of the matching remotes for the specified branch name. To achieve that, add an optional feature to the `unique_tracking_name()` function that allows the matching remote names to be exposed to the caller. Signed-off-by: Yoichi NAKAYAMA --- builtin/checkout.c | 28 ++++++++++++++++++++-------- builtin/worktree.c | 4 ++-- checkout.c | 14 ++++++++++++-- checkout.h | 5 ++++- 4 files changed, 38 insertions(+), 13 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 650eda735fc526..07373615d833aa 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -1343,9 +1343,12 @@ enum checkout_command { CHECKOUT_RESTORE = 3, }; -static void advice_disambiguating_remotes(enum checkout_command which_command) +static void advise_disambiguating_remotes(enum checkout_command which_command, + const char *branch, + const struct string_list *matched_remote_names) { const char *cmdname; + struct string_list_item *item; switch (which_command) { case CHECKOUT_CHECKOUT: @@ -1360,15 +1363,19 @@ static void advice_disambiguating_remotes(enum checkout_command which_command) break; } - advise(_("If you meant to check out a remote tracking branch on, e.g. 'origin',\n" + advise(_("Branch name '%s' appears in multiple remotes:"), branch); + for_each_string_list_item(item, matched_remote_names) { + advise(_(" %s"), item->string); + } + advise(_("If you meant to check out a remote tracking branch on ,\n" "you can do so by fully qualifying the name with the --track option:\n" "\n" - " git %s --track origin/\n" + " git %s --track /%s\n" "\n" - "If you'd like to always have checkouts of an ambiguous prefer\n" + "If you'd like to always have checkouts of an ambiguous name prefer\n" "one remote, e.g. the 'origin' remote, consider setting\n" "checkout.defaultRemote=origin in your config."), - cmdname); + cmdname, branch); } static char *parse_remote_branch(const char *arg, @@ -1377,7 +1384,10 @@ static char *parse_remote_branch(const char *arg, enum checkout_command which_command) { int num_matches = 0; - char *remote = unique_tracking_name(arg, rev, &num_matches); + struct string_list matched_remote_names = STRING_LIST_INIT_DUP; + + char *remote = unique_tracking_name(arg, rev, &num_matches, + &matched_remote_names); if (remote && could_be_checkout_paths) { die(_("'%s' could be both a local file and a tracking branch.\n" @@ -1387,12 +1397,14 @@ static char *parse_remote_branch(const char *arg, if (!remote && num_matches > 1) { if (advice_enabled(ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME)) - advice_disambiguating_remotes(which_command); - + advise_disambiguating_remotes(which_command, arg, + &matched_remote_names); die(_("'%s' matched multiple (%d) remote tracking branches"), arg, num_matches); } + string_list_clear(&matched_remote_names, 0); + return remote; } diff --git a/builtin/worktree.c b/builtin/worktree.c index 654d27c3e1ce99..22c8e5e1311d87 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -782,7 +782,7 @@ static char *dwim_branch(const char *path, char **new_branch) *new_branch = branchname; if (guess_remote) { struct object_id oid; - char *remote = unique_tracking_name(*new_branch, &oid, NULL); + char *remote = unique_tracking_name(*new_branch, &oid, NULL, NULL); return remote; } return NULL; @@ -904,7 +904,7 @@ static int add(int ac, const char **av, const char *prefix, commit = lookup_commit_reference_by_name(branch); if (!commit) { - remote = unique_tracking_name(branch, &oid, NULL); + remote = unique_tracking_name(branch, &oid, NULL, NULL); if (remote) { new_branch = branch; branch = new_branch_to_free = remote; diff --git a/checkout.c b/checkout.c index 1588b116eedf06..2806b783ece4e6 100644 --- a/checkout.c +++ b/checkout.c @@ -8,6 +8,7 @@ #include "checkout.h" #include "config.h" #include "strbuf.h" +#include "string-list.h" struct tracking_name_data { /* const */ char *src_ref; @@ -17,6 +18,7 @@ struct tracking_name_data { const char *default_remote; char *default_dst_ref; struct object_id *default_dst_oid; + struct string_list **remote_names; }; #define TRACKING_NAME_DATA_INIT { 0 } @@ -39,6 +41,8 @@ static int check_tracking_name(struct remote *remote, void *cb_data) oidcpy(dst, cb->dst_oid); cb->default_dst_oid = dst; } + if (cb->remote_names) + string_list_append(*cb->remote_names, remote->name); if (cb->dst_ref) { free(query.dst); return 0; @@ -48,14 +52,20 @@ static int check_tracking_name(struct remote *remote, void *cb_data) } char *unique_tracking_name(const char *name, struct object_id *oid, - int *dwim_remotes_matched) + int *dwim_remotes_matched, + struct string_list *dwim_remote_names) { struct tracking_name_data cb_data = TRACKING_NAME_DATA_INIT; const char *default_remote = NULL; - if (!repo_config_get_string_tmp(the_repository, "checkout.defaultremote", &default_remote)) + + if (!repo_config_get_string_tmp(the_repository, + "checkout.defaultremote", + &default_remote)) cb_data.default_remote = default_remote; cb_data.src_ref = xstrfmt("refs/heads/%s", name); cb_data.dst_oid = oid; + if (dwim_remote_names) + cb_data.remote_names = &dwim_remote_names; for_each_remote(check_tracking_name, &cb_data); if (dwim_remotes_matched) *dwim_remotes_matched = cb_data.num_matches; diff --git a/checkout.h b/checkout.h index 55920e7aeb243d..0b185a0fc934eb 100644 --- a/checkout.h +++ b/checkout.h @@ -3,6 +3,8 @@ #include "hash.h" +struct string_list; + /* * Check if the branch name uniquely matches a branch name on a remote * tracking branch. Return the name of the remote if such a branch @@ -10,6 +12,7 @@ */ char *unique_tracking_name(const char *name, struct object_id *oid, - int *dwim_remotes_matched); + int *dwim_remotes_matched, + struct string_list *dwim_remote_names); #endif /* CHECKOUT_H */ From 095a5796d4c92012825daa07eef67140a7461018 Mon Sep 17 00:00:00 2001 From: Yoichi NAKAYAMA Date: Sat, 22 Aug 2026 08:33:08 +0900 Subject: [PATCH 3/3] worktree add: improve message for ambiguous remote branch name When the user runs 'git worktree add ../foo-dir bar-topic' without specifying a remote, and there is no local branch named bar-topic, we try to guess which remote branch bar-topic refers to, then create a new branch named bar-topic that tracks the remote branch. If multiple remotes have a branch named bar-topic, we silently gave up, leaving the variable 'branch' intact. We then entered the conditional clause 'if (!opts.orphan && !lookup_commit_reference_by_name(branch))' and triggered an "invalid reference" error. This error message did not provide enough information to resolve the ambiguity. When multiple matching branches are found, display a hint and a descriptive error message and die immediately. Signed-off-by: Yoichi NAKAYAMA --- builtin/worktree.c | 37 ++++++++++++++++++++++++++++++++++--- t/t2400-worktree-add.sh | 4 ++-- 2 files changed, 36 insertions(+), 5 deletions(-) diff --git a/builtin/worktree.c b/builtin/worktree.c index 22c8e5e1311d87..320b18873df639 100644 --- a/builtin/worktree.c +++ b/builtin/worktree.c @@ -788,6 +788,25 @@ static char *dwim_branch(const char *path, char **new_branch) return NULL; } +static void advise_disambiguating_remotes(const char *path, const char *branch, + const struct string_list *matched_remote_names) +{ + struct string_list_item *item; + + advise(_("Branch name '%s' appears in multiple remotes:"), branch); + for_each_string_list_item(item, matched_remote_names) { + advise(_(" %s"), item->string); + } + advise(_("If you meant to create a worktree from a remote tracking branch on\n" + ", you can do so by:\n" + "\n" + " git worktree add -b %s %s /%s\n" + "\n" + "If you'd like to always prefer some remote, e.g. 'origin',\n" + "consider setting checkout.defaultRemote=origin in your config."), + branch, path, branch); +} + static int add(int ac, const char **av, const char *prefix, struct repository *repo UNUSED) { @@ -898,17 +917,29 @@ static int add(int ac, const char **av, const char *prefix, /* DWIM: Infer --orphan when repo has no refs. */ opts.orphan = (!s) && dwim_orphan(&opts, !!opt_track, 1); } else if (ac == 2) { - struct object_id oid; struct commit *commit; - char *remote; commit = lookup_commit_reference_by_name(branch); if (!commit) { - remote = unique_tracking_name(branch, &oid, NULL, NULL); + struct object_id oid; + char *remote; + int num_matches = 0; + struct string_list matched_remote_names = STRING_LIST_INIT_DUP; + + remote = unique_tracking_name(branch, &oid, &num_matches, + &matched_remote_names); if (remote) { new_branch = branch; branch = new_branch_to_free = remote; + } else if (num_matches > 1) { + if (!opts.quiet && + advice_enabled(ADVICE_CHECKOUT_AMBIGUOUS_REMOTE_BRANCH_NAME)) + advise_disambiguating_remotes(path, branch, + &matched_remote_names); + die(_("'%s' matched multiple (%d) remote tracking branches"), + branch, num_matches); } + string_list_clear(&matched_remote_names, 0); } if (!strcmp(branch, "HEAD")) diff --git a/t/t2400-worktree-add.sh b/t/t2400-worktree-add.sh index 87b926728ad8cf..5c105cf2529bfa 100755 --- a/t/t2400-worktree-add.sh +++ b/t/t2400-worktree-add.sh @@ -624,12 +624,12 @@ test_expect_success '"add" dwims' ' test_expect_success '"add" dwims with checkout.defaultRemote' ' test_when_finished rm -rf repo_upstream repo_dwim foo && setup_remote_repo repo_upstream repo_dwim && - git init repo_dwim && ( cd repo_dwim && git remote add repo_upstream2 ../repo_upstream && git fetch repo_upstream2 && - test_must_fail git worktree add ../foo foo && + test_must_fail git worktree add ../foo foo 2>error.actual && + test_grep "matched multiple (2) remote tracking branches" error.actual && git -c checkout.defaultRemote=repo_upstream worktree add ../foo foo && git status -uno --porcelain >status.actual && test_must_be_empty status.actual