Merge branch 'jc/index-output'

* jc/index-output:
  git-read-tree --index-output=<file>
  _GIT_INDEX_OUTPUT: allow plumbing to output to an alternative index file.

Conflicts:

	builtin-apply.c

1 files changed, 13 insertions, 1 deletions

diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
index 0ff2890c7..019c8bef7 100644
--- a/Documentation/git-read-tree.txt
+++ b/Documentation/git-read-tree.txt
@@ -8,7 +8,7 @@ git-read-tree - Reads tree information into the index
 
 SYNOPSIS
 --------
-'git-read-tree' (<tree-ish> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
+'git-read-tree' (<tree-ish> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]])
 
 
 DESCRIPTION
@@ -86,6 +86,18 @@ OPTIONS
 	file (usually '.gitignore') and allows such an untracked
 	but explicitly ignored file to be overwritten.
 
+--index-output=<file>::
+	Instead of writing the results out to `$GIT_INDEX_FILE`,
+	write the resulting index in the named file.  While the
+	command is operating, the original index file is locked
+	with the same mechanism as usual.  The file must allow
+	to be rename(2)ed into from a temporary file that is
+	created next to the usual index file; typically this
+	means it needs to be on the same filesystem as the index
+	file itself, and you need write permission to the
+	directories the index file and index output file are
+	located in.
+
 <tree-ish#>::
 	The id of the tree object(s) to be read/merged.