branch: give advice when tracking start-point is missing

If the user requests to --set-upstream-to a branch that does
not exist, then either:

1. It was a typo.

2. They thought the branch should exist.

In case (1), there is not much we can do beyond showing the
name we tried to use. For case (2), though, we can help to
guide them through common workflows.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/advice.c b/advice.c
index 3bc86260b8a2a809a379c91627f919ef0a529aa1..a8deee6e6419a1e867e06e90a70300cd2e01b556 100644 (file)
--- a/advice.c
+++ b/advice.c
@@ -13,6 +13,7 @@ int advice_commit_before_merge = 1;
 int advice_resolve_conflict = 1;
 int advice_implicit_identity = 1;
 int advice_detached_head = 1;
+int advice_set_upstream_failure = 1;
 
 static struct {
        const char *name;
@@ -31,6 +32,7 @@ static struct {
        { "resolveconflict", &advice_resolve_conflict },
        { "implicitidentity", &advice_implicit_identity },
        { "detachedhead", &advice_detached_head },
+       { "setupstreamfailure", &advice_set_upstream_failure },
 
        /* make this an alias for backward compatibility */
        { "pushnonfastforward", &advice_push_update_rejected }

diff --git a/advice.h b/advice.h
index af0c983c686b9ca5be2e8631562e60bd19656c22..94caa32f9213f59a627176ec8b4aea022f6b0f8f 100644 (file)
--- a/advice.h
+++ b/advice.h
@@ -16,6 +16,7 @@ extern int advice_commit_before_merge;
 extern int advice_resolve_conflict;
 extern int advice_implicit_identity;
 extern int advice_detached_head;
+extern int advice_set_upstream_failure;
 
 int git_default_advice_config(const char *var, const char *value);
 void advise(const char *advice, ...);

diff --git a/branch.c b/branch.c
index d6f40015d7fc1b50ff7898d5e60510a54d76e0ec..6ae6a4c321ab8866a3e21f15302b5549a95b4646 100644 (file)
--- a/branch.c
+++ b/branch.c
@@ -200,7 +200,16 @@ int validate_new_branchname(const char *name, struct strbuf *ref,
 static const char upstream_not_branch[] =
 N_("Cannot setup tracking information; starting point '%s' is not a branch.");
 static const char upstream_missing[] =
-N_("Cannot setup tracking information; starting point '%s' does not exist");
+N_("the requested upstream branch '%s' does not exist");
+static const char upstream_advice[] =
+N_("\n"
+"If you are planning on basing your work on an upstream\n"
+"branch that already exists at the remote, you may need to\n"
+"run \"git fetch\" to retrieve it.\n"
+"\n"
+"If you are planning to push out a new local branch that\n"
+"will track its remote counterpart, you may want to use\n"
+"\"git push -u\" to set the upstream config as you push.");
 
 void create_branch(const char *head,
                   const char *name, const char *start_name,
@@ -230,8 +239,14 @@ void create_branch(const char *head,
 
        real_ref = NULL;
        if (get_sha1(start_name, sha1)) {
-               if (explicit_tracking)
+               if (explicit_tracking) {
+                       if (advice_set_upstream_failure) {
+                               error(_(upstream_missing), start_name);
+                               advise(_(upstream_advice));
+                               exit(1);
+                       }
                        die(_(upstream_missing), start_name);
+               }
                die("Not a valid object name: '%s'.", start_name);
        }