Merge branch 'jc/lt-ref2-with-lt-refs' into jc/ref-locking

* jc/lt-ref2-with-lt-refs:
  Fix show-ref usage for --dereference.
  Document git-show-ref [-s|--hash] option.
  Add man page for git-show-ref
  gitignore: git-show-ref is a generated file.
  Use Linus' show ref in "git-branch.sh".
  Add [-s|--hash] option to Linus' show-ref.
  Teach "git checkout" to use git-show-ref
  Add "git show-ref" builtin command

1 files changed, 152 insertions, 0 deletions

diff --git a/Documentation/git-show-ref.txt b/Documentation/git-show-ref.txt
new file mode 100644
index 0000000000..b724d832c8
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+++ b/Documentation/git-show-ref.txt
@@ -0,0 +1,152 @@
+git-show-ref(1)
+===============
+
+NAME
+----
+git-show-ref - List references in a local repository
+
+SYNOPSIS
+--------
+[verse]
+'git-show-ref' [-q|--quiet] [--verify] [-h|--head] [-d|--dereference]
+	     [-s|--hash] [--tags] [--heads] [--] <pattern>...
+
+DESCRIPTION
+-----------
+
+Displays references available in a local repository along with the associated
+commit IDs. Results can be filtered using a pattern and tags can be
+dereferenced into object IDs. Additionally, it can be used to test whether a
+particular ref exists.
+
+Use of this utility is encouraged in favor of directly accessing files under
+in the `.git` directory.
+
+OPTIONS
+-------
+
+-h, --head::
+
+	Show the HEAD reference.
+
+--tags, --heads::
+
+	Limit to only "refs/heads" and "refs/tags", respectively.  These
+	options are not mutually exclusive; when given both, references stored
+	in "refs/heads" and "refs/tags" are displayed.
+
+-d, --dereference::
+
+	Dereference tags into object IDs. They will be shown with "^{}"
+	appended.
+
+-s, --hash::
+
+	Only show the SHA1 hash, not the reference name. When also using
+	--dereference the dereferenced tag will still be shown after the SHA1,
+	this maybe a bug.
+
+--verify::
+
+	Enable stricter reference checking by requiring an exact ref path.
+	Aside from returning an error code of 1, it will also print an error
+	message if '--quiet' was not specified.
+
+-q, --quiet::
+
+	Do not print any results to stdout. When combined with '--verify' this
+	can be used to silently check if a reference exists.
+
+<pattern>::
+
+	Show references matching one or more patterns.
+
+OUTPUT
+------
+
+The output is in the format: '<SHA-1 ID>' '<space>' '<reference name>'.
+
+-----------------------------------------------------------------------------
+$ git show-ref --head --dereference
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 HEAD
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/master
+832e76a9899f560a90ffd62ae2ce83bbeff58f54 refs/heads/origin
+3521017556c5de4159da4615a39fa4d5d2c279b5 refs/tags/v0.99.9c
+6ddc0964034342519a87fe013781abf31c6db6ad refs/tags/v0.99.9c^{}
+055e4ae3ae6eb344cbabf2a5256a49ea66040131 refs/tags/v1.0rc4
+423325a2d24638ddcc82ce47be5e40be550f4507 refs/tags/v1.0rc4^{}
+...
+-----------------------------------------------------------------------------
+
+When using --hash (and not --dereference) the output format is: '<SHA-1 ID>'
+
+-----------------------------------------------------------------------------
+$ git show-ref --heads --hash
+2e3ba0114a1f52b47df29743d6915d056be13278
+185008ae97960c8d551adcd9e23565194651b5d1
+03adf42c988195b50e1a1935ba5fcbc39b2b029b
+...
+-----------------------------------------------------------------------------
+
+EXAMPLE
+-------
+
+To show all references called "master", whether tags or heads or anything
+else, and regardless of how deep in the reference naming hierarchy they are,
+use:
+
+-----------------------------------------------------------------------------
+	git show-ref master
+-----------------------------------------------------------------------------
+
+This will show "refs/heads/master" but also "refs/remote/other-repo/master",
+if such references exists.
+
+When using the '--verify' flag, the command requires an exact path:
+
+-----------------------------------------------------------------------------
+	git show-ref --verify refs/heads/master
+-----------------------------------------------------------------------------
+
+will only match the exact branch called "master".
+
+If nothing matches, gitlink:git-show-ref[1] will return an error code of 1,
+and in the case of verification, it will show an error message.
+
+For scripting, you can ask it to be quiet with the "--quiet" flag, which
+allows you to do things like
+
+-----------------------------------------------------------------------------
+	git-show-ref --quiet --verify -- "refs/heads/$headname" ||
+		echo "$headname is not a valid branch"
+-----------------------------------------------------------------------------
+
+to check whether a particular branch exists or not (notice how we don't
+actually want to show any results, and we want to use the full refname for it
+in order to not trigger the problem with ambiguous partial matches).
+
+To show only tags, or only proper branch heads, use "--tags" and/or "--heads"
+respectively (using both means that it shows tags and heads, but not other
+random references under the refs/ subdirectory).
+
+To do automatic tag object dereferencing, use the "-d" or "--dereference"
+flag, so you can do
+
+-----------------------------------------------------------------------------
+	git show-ref --tags --dereference
+-----------------------------------------------------------------------------
+
+to get a listing of all tags together with what they dereference.
+
+SEE ALSO
+--------
+gitlink:git-ls-remote[1], gitlink:git-peek-remote[1]
+
+AUTHORS
+-------
+Written by Linus Torvalds <torvalds@osdl.org>.
+Man page by Jonas Fonseca <fonseca@diku.dk>.
+
+GIT
+---
+Part of the gitlink:git[7] suite