Merge commit 'b319ef7' into jc/maint-fix-test-perm

* commit 'b319ef7': (8132 commits)
  Add a small patch-mode testing library
  git-apply--interactive: Refactor patch mode code
  t8005: Nobody writes Russian in shift_jis
  Fix severe breakage in "git-apply --whitespace=fix"
  Update release notes for 1.6.4
  After renaming a section, print any trailing variable definitions
  Make section_name_match start on '[', and return the length on success
  send-email: detect cycles in alias expansion
  Show the presence of untracked files in the bash prompt.
  SunOS grep does not understand -C<n> nor -e
  Fix export_marks() error handling.
  git repack: keep commits hidden by a graft
  Add a test showing that 'git repack' throws away grafted-away parents
  git branch: clean up detached branch handling
  git branch: avoid unnecessary object lookups
  git branch: fix performance problem
  git svn: fix shallow clone when upstream revision is too new
  do_one_ref(): null_sha1 check is not about broken ref
  configure.ac: properly unset NEEDS_SSL_WITH_CRYPTO when sha1 func is missing
  janitor: useless checks before free
  ...

1 files changed, 22 insertions, 0 deletions

diff --git a/t/t2011-checkout-invalid-head.sh b/t/t2011-checkout-invalid-head.sh
new file mode 100755
index 0000000000..15ebdc26eb
--- /dev/null
+++ b/t/t2011-checkout-invalid-head.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+
+test_description='checkout switching away from an invalid branch'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo hello >world &&
+	git add world &&
+	git commit -m initial
+'
+
+test_expect_success 'checkout should not start branch from a tree' '
+	test_must_fail git checkout -b newbranch master^{tree}
+'
+
+test_expect_success 'checkout master from invalid HEAD' '
+	echo 0000000000000000000000000000000000000000 >.git/HEAD &&
+	git checkout master --
+'
+
+test_done