Merge branch 'jc/push-default-explicit'

A lazy "git push" without refspec did not internally use a fully
specified refspec to perform 'current', 'simple', or 'upstream'
push, causing unnecessary "ambiguous ref" errors.

* jc/push-default-explicit:
  push: test pushing ambiguously named branches
  push: do not use potentially ambiguous default refspec

Author: gitster

builtin/push.c

@@ -194,15 +194,18 @@ static void setup_push_upstream(struct remote *remote, struct branch *branch,
 			die_push_simple(branch, remote);
 	}
 
-	strbuf_addf(&refspec, "%s:%s", branch->name, branch->merge[0]->src);
+	strbuf_addf(&refspec, "%s:%s", branch->refname, branch->merge[0]->src);
 	add_refspec(refspec.buf);
 }
 
 static void setup_push_current(struct remote *remote, struct branch *branch)
 {
+	struct strbuf refspec = STRBUF_INIT;
+
 	if (!branch)
 		die(_(message_detached_head_die), remote->name);
-	add_refspec(branch->name);
+	strbuf_addf(&refspec, "%s:%s", branch->refname, branch->refname);
+	add_refspec(refspec.buf);
 }
 
 static int is_workflow_triangular(struct remote *remote)

t/t5528-push-default.sh

@@ -98,6 +98,16 @@ test_expect_success 'push from/to new branch with upstream, matching and simple'
 	test_push_failure upstream
 '
 
+test_expect_success 'push ambiguously named branch with upstream, matching and simple' '
+	git checkout -b ambiguous &&
+	test_config branch.ambiguous.remote parent1 &&
+	test_config branch.ambiguous.merge refs/heads/ambiguous &&
+	git tag ambiguous &&
+	test_push_success simple ambiguous &&
+	test_push_success matching ambiguous &&
+	test_push_success upstream ambiguous
+'
+
 test_expect_success 'push from/to new branch with current creates remote branch' '
 	test_config branch.new-branch.remote repo1 &&
 	git checkout new-branch &&