From 2096948158ea0b253a68a81c691fdf88ff00589a Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Thu, 29 Jan 2026 11:06:15 -0800 Subject: [PATCH 1/2] checkout: pass program-readable token to unified "main" The "git checkout", "git switch", and "git restore" commands share a single implementation, checkout_main(), which switches error message it gives using the usage string passed by each of these three front-ends. In order to be able to tweak behaviours of the commands based on which one we are executing, invent an enum that denotes which one of these three commands is currently executing, and pass that to checkout_main() instead. With this step, there is no externally visible behaviour change, as this enum parameter is only used to choose among the three usage strings. Signed-off-by: Junio C Hamano --- builtin/checkout.c | 63 +++++++++++++++++++++++++++++++--------------- 1 file changed, 43 insertions(+), 20 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index f9453473fe..2411108856 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -43,22 +43,6 @@ #include "parallel-checkout.h" #include "add-interactive.h" -static const char * const checkout_usage[] = { - N_("git checkout [] "), - N_("git checkout [] [] -- ..."), - NULL, -}; - -static const char * const switch_branch_usage[] = { - N_("git switch [] []"), - NULL, -}; - -static const char * const restore_usage[] = { - N_("git restore [] [--source=] ..."), - NULL, -}; - struct checkout_opts { int patch_mode; int patch_context; @@ -1293,6 +1277,13 @@ static void setup_new_branch_info_and_source_tree( } } + +enum checkout_command { + CHECKOUT_CHECKOUT = 1, + CHECKOUT_SWITCH = 2, + CHECKOUT_RESTORE = 3, +}; + static char *parse_remote_branch(const char *arg, struct object_id *rev, int could_be_checkout_paths) @@ -1767,12 +1758,44 @@ static char cb_option = 'b'; static int checkout_main(int argc, const char **argv, const char *prefix, struct checkout_opts *opts, struct option *options, - const char * const usagestr[]) + enum checkout_command which_command) { int parseopt_flags = 0; struct branch_info new_branch_info = { 0 }; int ret; + static const char * const checkout_usage[] = { + N_("git checkout [] "), + N_("git checkout [] [] -- ..."), + NULL, + }; + + static const char * const switch_branch_usage[] = { + N_("git switch [] []"), + NULL, + }; + + static const char * const restore_usage[] = { + N_("git restore [] [--source=] ..."), + NULL, + }; + + const char * const *usagestr; + + switch (which_command) { + case CHECKOUT_CHECKOUT: + usagestr = checkout_usage; + break; + case CHECKOUT_SWITCH: + usagestr = switch_branch_usage; + break; + case CHECKOUT_RESTORE: + usagestr = restore_usage; + break; + default: + BUG("no such checkout variant %d", which_command); + } + opts->overwrite_ignore = 1; opts->prefix = prefix; opts->show_progress = -1; @@ -2032,7 +2055,7 @@ int cmd_checkout(int argc, options = add_checkout_path_options(&opts, options); return checkout_main(argc, argv, prefix, &opts, options, - checkout_usage); + CHECKOUT_CHECKOUT); } int cmd_switch(int argc, @@ -2071,7 +2094,7 @@ int cmd_switch(int argc, cb_option = 'c'; return checkout_main(argc, argv, prefix, &opts, options, - switch_branch_usage); + CHECKOUT_SWITCH); } int cmd_restore(int argc, @@ -2107,5 +2130,5 @@ int cmd_restore(int argc, options = add_checkout_path_options(&opts, options); return checkout_main(argc, argv, prefix, &opts, options, - restore_usage); + CHECKOUT_RESTORE); } From 12fee11f21e9b63626da5058fa055f95d55a5515 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Thu, 29 Jan 2026 11:06:16 -0800 Subject: [PATCH 2/2] checkout: tell "parse_remote_branch" which command is calling it When "git checkout " and "git switch " need to error out due to ambiguity of the branch name , these two commands give an advise message with a sample command that tells the user how to disambiguate from the parse_remote_branch() function. The sample command hardcodes "git checkout", since this feature predates "git switch" by a large margin. To a user who said "git switch " and got this message, it is confusing. Pass the "enum checkout_command", which was invented in the previous step for this exact purpose, down the call chain leading to parse_remote_branch() function to change the sample command shown to the user in this advise message. Also add a bit more test coverage for this "fail to DWIM under ambiguity" that we lack, as well as the message we produce when we fail. Reported-by: Simon Cheng Signed-off-by: Junio C Hamano --- builtin/checkout.c | 29 ++++++++++++++++++++++++----- t/t2027-checkout-track.sh | 18 ++++++++++++++++++ 2 files changed, 42 insertions(+), 5 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 2411108856..f2c5df9631 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -1286,7 +1286,8 @@ enum checkout_command { static char *parse_remote_branch(const char *arg, struct object_id *rev, - int could_be_checkout_paths) + int could_be_checkout_paths, + enum checkout_command which_command) { int num_matches = 0; char *remote = unique_tracking_name(arg, rev, &num_matches); @@ -1299,14 +1300,30 @@ 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 checkout --track origin/\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.")); + "checkout.defaultRemote=origin in your config."), + cmdname); } die(_("'%s' matched multiple (%d) remote tracking branches"), @@ -1318,6 +1335,7 @@ static char *parse_remote_branch(const char *arg, static int parse_branchname_arg(int argc, const char **argv, int dwim_new_local_branch_ok, + enum checkout_command which_command, struct branch_info *new_branch_info, struct checkout_opts *opts, struct object_id *rev) @@ -1427,7 +1445,8 @@ static int parse_branchname_arg(int argc, const char **argv, if (recover_with_dwim) { remote = parse_remote_branch(arg, rev, - could_be_checkout_paths); + could_be_checkout_paths, + which_command); if (remote) { *new_branch = arg; arg = remote; @@ -1916,7 +1935,7 @@ 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, + int n = parse_branchname_arg(argc, argv, dwim_ok, which_command, &new_branch_info, opts, &rev); argv += n; argc -= n; diff --git a/t/t2027-checkout-track.sh b/t/t2027-checkout-track.sh index a397790df5..c01f1cd617 100755 --- a/t/t2027-checkout-track.sh +++ b/t/t2027-checkout-track.sh @@ -47,4 +47,22 @@ test_expect_success 'checkout --track -b overrides autoSetupMerge=inherit' ' test_cmp_config refs/heads/main branch.b4.merge ' +test_expect_success 'ambiguous tracking info' ' + # Set up a few remote repositories + git init --bare --initial-branch=trunk src1 && + git init --bare --initial-branch=trunk src2 && + git push src1 one:refs/heads/trunk && + git push src2 two:refs/heads/trunk && + + git remote add -f src1 "file://$PWD/src1" && + git remote add -f src2 "file://$PWD/src2" && + + # DWIM + test_must_fail git checkout trunk 2>hint.checkout && + test_grep "hint: *git checkout --track" hint.checkout && + + test_must_fail git switch trunk 2>hint.switch && + test_grep "hint: *git switch --track" hint.switch +' + test_done