[PATCH v5 7/8] checkout: add advice for ambiguous "checkout "

[Ævar Arnfjörð Bjarmason]

As the "checkout" documentation describes:

If  is not found but there does exist a tracking branch in
exactly one remote (call it ) with a matching name, treat
as equivalent to [...] /

Signed-off-by: Ævar Arnfjörð Bjarmason 
---
 Documentation/config.txt |  7 +++
 advice.c |  2 ++
 advice.h |  1 +
 builtin/checkout.c   | 13 +
 t/t2024-checkout-dwim.sh | 14 ++
 5 files changed, 37 insertions(+)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index ab641bf5a9..dfc0413a84 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -344,6 +344,13 @@ advice.*::
Advice shown when you used linkgit:git-checkout[1] to
move to the detach HEAD state, to instruct how to create
a local branch after the fact.
+   checkoutAmbiguousRemoteBranchName::
+   Advice shown when the argument to
+   linkgit:git-checkout[1] ambiguously resolves to a
+   remote tracking branch on more than one remote in
+   situations where an unambiguous argument would have
+   otherwise caused a remote-tracking branch to be
+   checked out.
amWorkDir::
Advice that shows the location of the patch file when
linkgit:git-am[1] fails to apply it.
diff --git a/advice.c b/advice.c
index 370a56d054..75e7dede90 100644
--- a/advice.c
+++ b/advice.c
@@ -21,6 +21,7 @@ int advice_add_embedded_repo = 1;
 int advice_ignored_hook = 1;
 int advice_waiting_for_editor = 1;
 int advice_graft_file_deprecated = 1;
+int advice_checkout_ambiguous_remote_branch_name = 1;
 
 static int advice_use_color = -1;
 static char advice_colors[][COLOR_MAXLEN] = {
@@ -72,6 +73,7 @@ static struct {
{ "ignoredhook", &advice_ignored_hook },
{ "waitingforeditor", &advice_waiting_for_editor },
{ "graftfiledeprecated", &advice_graft_file_deprecated },
+   { "checkoutambiguousremotebranchname", 
&advice_checkout_ambiguous_remote_branch_name },
 
/* make this an alias for backward compatibility */
{ "pushnonfastforward", &advice_push_update_rejected }
diff --git a/advice.h b/advice.h
index 9f5064e82a..4d11d51d43 100644
--- a/advice.h
+++ b/advice.h
@@ -22,6 +22,7 @@ extern int advice_add_embedded_repo;
 extern int advice_ignored_hook;
 extern int advice_waiting_for_editor;
 extern int advice_graft_file_deprecated;
+extern int advice_checkout_ambiguous_remote_branch_name;
 
 int git_default_advice_config(const char *var, const char *value);
 __attribute__((format (printf, 1, 2)))
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 8c93c55cbc..4dfb8f1535 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -22,6 +22,7 @@
 #include "resolve-undo.h"
 #include "submodule-config.h"
 #include "submodule.h"
+#include "advice.h"
 
 static const char * const checkout_usage[] = {
N_("git checkout [] "),
@@ -1267,6 +1268,18 @@ int cmd_checkout(int argc, const char **argv, const char 
*prefix)
UNLEAK(opts);
if (opts.patch_mode || opts.pathspec.nr) {
int ret = checkout_paths(&opts, new_branch_info.name);
+   if (ret && dwim_remotes_matched > 1 &&
+   advice_checkout_ambiguous_remote_branch_name)
+   advise(_("The argument '%s' matched more than one 
remote tracking branch.\n"
+"We found %d remotes with a reference that 
matched. So we fell back\n"
+"on trying to resolve the argument as a path, 
but failed there too!\n"
+"\n"
+"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/"),
+  argv[0],
+  dwim_remotes_matched);
return ret;
} else {
return checkout_branch(&opts, &new_branch_info);
diff --git a/t/t2024-checkout-dwim.sh b/t/t2024-checkout-dwim.sh
index ed32828105..fef263a858 100755
--- a/t/t2024-checkout-dwim.sh
+++ b/t/t2024-checkout-dwim.sh
@@ -76,6 +76,20 @@ test_expect_success 'checkout of branch from multiple 
remotes fails #1' '
test_branch master
 '
 
+test_expect_success 'checkout of branch from multiple remotes fails with 
advice' '
+   git checkout -B master &&
+   test_might_fail git branch -D foo &&
+   test_must_fail git checkout foo 2>stderr &&
+   test_branch master &&
+   status_uno_is_clean &&
+   test_i18ngrep "^hint: " stderr &&
+   test_must_fail git -c advice.checkoutAmbiguousRemoteBranchName=false \
+   checkout foo 2>stderr &&
+   test_branch master &&
+   status_un

Re: [PATCH v5 7/8] checkout: add advice for ambiguous "checkout "

[Eric Sunshine]

On Fri, Jun 1, 2018 at 5:10 PM, Ævar Arnfjörð Bjarmason
 wrote:
> As the "checkout" documentation describes:
>
> If  is not found but there does exist a tracking branch in
> exactly one remote (call it ) with a matching name, treat
> as equivalent to [...] /
> This is a really useful feature. The problem is that when you and

s/and/add/

> another remote (e.g. a fork) git won't find a unique branch name

Missing comma: s/)/),/

> anymore, and will instead print this nondescript message:

Perhaps s/nondescript/unhelpful/ ?

> $ git checkout master
> error: pathspec 'master' did not match any file(s) known to git
>
> Now it will, on my git.git checkout, print:
>
> $ ./git --exec-path=$PWD checkout master
> error: pathspec 'master' did not match any file(s) known to git.
> hint: The argument 'master' matched more than one remote tracking branch.
> hint: We found 26 remotes with a reference that matched. So we fell back
> hint: on trying to resolve the argument as a path, but failed there too!
> hint:
> hint: If you meant to check out a remote tracking branch on e.g. 'origin'

Missing commas: s/on e.g. 'origin'/on, e.g. 'origin',/

> hint: you can do so by fully-qualifying the name with the --track option:

s/fully-qualifying/fully qualifying/

> hint:
> hint: git checkout --track origin/
>
> Signed-off-by: Ævar Arnfjörð Bjarmason 

Aside from the s/and/add/ botch, all of the above are tiny nits which
don't actually impact the meaning of the commit message, thus not
really important.

> ---
> diff --git a/builtin/checkout.c b/builtin/checkout.c
> @@ -1267,6 +1268,18 @@ int cmd_checkout(int argc, const char **argv, const 
> char *prefix)
> +   if (ret && dwim_remotes_matched > 1 &&
> +   advice_checkout_ambiguous_remote_branch_name)
> +   advise(_("The argument '%s' matched more than one 
> remote tracking branch.\n"

You could drop "The argument" prefix, without hurting the meaning at
all, in order to gain a bit more horizontal space for the '%s'
interpolation. (Not worth a re-roll.)

> +"We found %d remotes with a reference that 
> matched. So we fell back\n"
> +"on trying to resolve the argument as a 
> path, but failed there too!\n"
> +"\n"
> +"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/"),
> +  argv[0],
> +  dwim_remotes_matched);