Merge branch 'nd/clone-detached'

* nd/clone-detached:
  clone: fix up delay cloning conditions
  push: do not let configured foreign-vcs permanently clobbered
  clone: print advice on checking out detached HEAD
  clone: allow --branch to take a tag
  clone: refuse to clone if --branch points to bogus ref
  clone: --branch=<branch> always means refs/heads/<branch>
  clone: delay cloning until after remote HEAD checking
  clone: factor out remote ref writing
  clone: factor out HEAD update code
  clone: factor out checkout code
  clone: write detached HEAD in bare repositories
  t5601: add missing && cascade

t/t5500-fetch-pack.sh

@@ -282,13 +282,6 @@ test_expect_success 'clone shallow object count' '
 	test_cmp count3.expected count3.actual
 '
 
-test_expect_success 'clone shallow with nonexistent --branch' '
-	git clone --depth 1 --branch Z "file://$(pwd)/." shallow4 &&
-	GIT_DIR=shallow4/.git git rev-parse HEAD >actual &&
-	git rev-parse HEAD >expected &&
-	test_cmp expected actual
-'
-
 test_expect_success 'clone shallow with detached HEAD' '
 	git checkout HEAD^ &&
 	git clone --depth 1 "file://$(pwd)/." shallow5 &&
@@ -318,4 +311,19 @@ EOF
 	test_cmp count6.expected count6.actual
 '
 
+test_expect_success 'shallow cloning single tag' '
+	git clone --depth 1 --branch=TAGB1 "file://$(pwd)/." shallow7 &&
+	cat >taglist.expected <<\EOF &&
+TAGB1
+TAGB2
+EOF
+	GIT_DIR=shallow7/.git git tag -l >taglist.actual &&
+	test_cmp taglist.expected taglist.actual &&
+
+	echo "in-pack: 7" > count7.expected &&
+	GIT_DIR=shallow7/.git git count-objects -v |
+		grep "^in-pack" > count7.actual &&
+	test_cmp count7.expected count7.actual
+'
+
 test_done

t/t5601-clone.sh

@@ -9,10 +9,13 @@ test_expect_success setup '
 	rm -fr .git &&
 	test_create_repo src &&
 	(
-		cd src
-		>file
-		git add file
-		git commit -m initial
+		cd src &&
+		>file &&
+		git add file &&
+		git commit -m initial &&
+		echo 1 >file &&
+		git add file &&
+		git commit -m updated
 	)
 
 '
@@ -88,6 +91,26 @@ test_expect_success 'clone --mirror' '
 
 '
 
+test_expect_success 'clone --mirror with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --mirror src mirror.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=mirror.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
+test_expect_success 'clone --bare with detached HEAD' '
+
+	( cd src && git checkout HEAD^ && git rev-parse HEAD >../expected ) &&
+	git clone --bare src bare.detached &&
+	( cd src && git checkout - ) &&
+	GIT_DIR=bare.detached git rev-parse HEAD >actual &&
+	test_cmp expected actual
+
+'
+
 test_expect_success 'clone --bare names the local repository <name>.git' '
 
 	git clone --bare src &&
@@ -248,4 +271,13 @@ test_expect_success 'clone from original with relative alternate' '
 	grep /src/\\.git/objects target-10/objects/info/alternates
 '
 
+test_expect_success 'clone checking out a tag' '
+	git clone --branch=some-tag src dst.tag &&
+	GIT_DIR=src/.git git rev-parse some-tag >expected &&
+	test_cmp expected dst.tag/.git/HEAD &&
+	GIT_DIR=dst.tag/.git git config remote.origin.fetch >fetch.actual &&
+	echo "+refs/heads/*:refs/remotes/origin/*" >fetch.expected &&
+	test_cmp fetch.expected fetch.actual
+'
+
 test_done

t/t5706-clone-branch.sh

@@ -57,12 +57,8 @@ test_expect_success 'clone -b does not munge remotes/origin/HEAD' '
 	)
 '
 
-test_expect_success 'clone -b with bogus branch chooses HEAD' '
-	git clone -b bogus parent clone-bogus &&
-	(cd clone-bogus &&
-	 check_HEAD master &&
-	 check_file one
-	)
+test_expect_success 'clone -b with bogus branch' '
+	test_must_fail git clone -b bogus parent clone-bogus
 '
 
 test_done