As the "checkout" documentation describes:
If <branch> is not found but there does exist a tracking branch in
exactly one remote (call it <remote>) with a matching name, treat
as equivalent to [...] <remote>/<branch.
This is a really useful feature. The problem is that when you add
another remote (e.g. a fork), git won't find a unique branch name
anymore, and will instead print this unhelpful message:
$ 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: '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',
hint: you can do so by fully qualifying the name with the --track option:
hint:
hint: git checkout --track origin/<name>
Note that the "error: pathspec[...]" message is still printed. This is
because whatever else checkout may have tried earlier, its final
fallback is to try to resolve the argument as a path. E.g. in this
case:
$ ./git --exec-path=$PWD checkout master pu
error: pathspec 'master' did not match any file(s) known to git.
error: pathspec 'pu' did not match any file(s) known to git.
There we don't print the "hint:" implicitly due to earlier logic
around the DWIM fallback. That fallback is only used if it looks like
we have one argument that might be a branch.
I can't think of an intrinsic reason for why we couldn't in some
future change skip printing the "error: pathspec[...]" error. However,
to do so we'd need to pass something down to checkout_paths() to make
it suppress printing an error on its own, and for us to be confident
that we're not silencing cases where those errors are meaningful.
I don't think that's worth it since determining whether that's the
case could easily change due to future changes in the checkout logic.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx>
---
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..baa027455a 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 [<options>] <branch>"),
@@ -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(_("'%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/<name>"),
+ 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_uno_is_clean &&
+ test_i18ngrep ! "^hint: " stderr
+'
+
test_expect_success 'checkout of branch from a single remote succeeds #1' '
git checkout -B master &&
test_might_fail git branch -D bar &&
--
2.17.0.290.gded63e768a
