[PATCH] Detect renames in diff family.

This rips out the rename detection engine from diff-helper and moves it
to the diff core, and updates the internal calling convention used by
diff-tree family into the diff core.  In order to give the same option
name to diff-tree family as well as to diff-helper, I've changed the
earlier diff-helper '-r' option to '-M' (stands for Move; sorry but the
natural abbreviation 'r' for 'rename' is already taken for 'recursive').

Although I did a fair amount of test with the git-diff-tree with
existing rename commits in the core GIT repository, this should still be
considered beta (preview) release.  This patch depends on the diff-delta
infrastructure just committed.

This implements almost everything I wanted to see in this series of
patch, except a few minor cleanups in the calling convention into diff
core, but that will be a separate cleanup patch.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 14 insertions, 5 deletions

diff --git a/Documentation/git-diff-cache.txt b/Documentation/git-diff-cache.txt
index b54b8226a..9cd610333 100644
--- a/Documentation/git-diff-cache.txt
+++ b/Documentation/git-diff-cache.txt
@@ -9,7 +9,7 @@ git-diff-cache - Compares content and mode of blobs between the cache and reposi
 
 SYNOPSIS
 --------
-'git-diff-cache' [-p] [-r] [-z] [-m] [--cached] <tree-ish>
+'git-diff-cache' [-p] [-r] [-z] [-m] [-M] [--cached] <tree-ish>
 
 DESCRIPTION
 -----------
@@ -33,6 +33,9 @@ OPTIONS
 -z::
 	\0 line termination on output
 
+-M::
+	Detect renames; implies -p.
+
 --cached::
 	do not consider the on-disk file at all
 
diff --git a/Documentation/git-diff-files.txt b/Documentation/git-diff-files.txt
index 0ad2f8955..166238f5c 100644
--- a/Documentation/git-diff-files.txt
+++ b/Documentation/git-diff-files.txt
@@ -9,7 +9,7 @@ git-diff-files - Compares files in the working tree and the cache
 
 SYNOPSIS
 --------
-'git-diff-files' [-p] [-q] [-r] [-z] [<pattern>...]
+'git-diff-files' [-p] [-q] [-r] [-z] [-M] [<pattern>...]
 
 DESCRIPTION
 -----------
@@ -26,6 +26,9 @@ OPTIONS
 -q::
 	Remain silent even on nonexisting files
 
+-M::
+	Detect renames; implies -p.
+
 -r::
 	This flag does not mean anything.  It is there only to match
 	git-diff-tree.  Unlike git-diff-tree, git-diff-files always looks
diff --git a/Documentation/git-diff-helper.txt b/Documentation/git-diff-helper.txt
index e930f9732..3c5d8fdf2 100644
--- a/Documentation/git-diff-helper.txt
+++ b/Documentation/git-diff-helper.txt
@@ -9,7 +9,7 @@ git-diff-helper - Generates patch format output for git-diff-*
 
 SYNOPSIS
 --------
-'git-diff-helper' [-z] [-R] [-r]
+'git-diff-helper' [-z] [-R] [-M]
 
 DESCRIPTION
 -----------
@@ -31,7 +31,7 @@ OPTIONS
 	would show a diff to bring the working file back to what
 	is in the <tree>.
 
--r::
+-M::
 	Detect renames.
 
 
diff --git a/Documentation/git-diff-tree.txt b/Documentation/git-diff-tree.txt
index ff7f25f3f..4c45c263b 100644
--- a/Documentation/git-diff-tree.txt
+++ b/Documentation/git-diff-tree.txt
@@ -9,7 +9,7 @@ git-diff-tree - Compares the content and mode of blobs found via two tree object
 
 SYNOPSIS
 --------
-'git-diff-tree' [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree-ish> <tree-ish> [<pattern>]\*
+'git-diff-tree' [-p] [-r] [-z] [--stdin] [-M] [-m] [-s] [-v] <tree-ish> <tree-ish> [<pattern>]\*
 
 DESCRIPTION
 -----------
@@ -33,6 +33,9 @@ OPTIONS
 	generate patch (see section on generating patches).  For
 	git-diff-tree, this flag implies '-r' as well.
 
+-M::
+	Detect renames; implies -p, in turn implying also '-r'.
+
 -r::
 	recurse