[PATCH] Add git-apply-patch-script.

I said:

     - Stop attempting to be compatible with cg-patch, and drop
       (mode:XXXXXX) bits from the diff.

     - Do keep the /dev/null change for created and deleted case.

     - No "Index:" line, no "Mode change:" line, anywhere in the
       output.  Anything that wants the mode bits and sha1 hash can
       do things from GIT_EXTERNAL_DIFF mechanism.  Maybe document
       suggested usage better.

This adds an example script git-apply-patch-script, that can be
used as the GIT_EXTERNAL_DIFF to apply changes between two trees
directly on the current work tree, like this:

 GIT_EXTERNAL_DIFF=git-apply-patch-script git-diff-tree -p <tree> <tree>

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

Makefile

@@ -12,8 +12,8 @@ CFLAGS=-g -O2 -Wall
 CC=gcc
 AR=ar
 
-SCRIPTS=git-merge-one-file-script git-prune-script git-pull-script \
-	git-tag-script
+SCRIPTS=git-apply-patch-script git-merge-one-file-script git-prune-script \
+	git-pull-script git-tag-script
 
 PROG=   git-update-cache git-diff-files git-init-db git-write-tree \
 	git-read-tree git-commit-tree git-cat-file git-fsck-cache \

git-apply-patch-script

@@ -0,0 +1,60 @@
+#!/bin/sh
+# Copyright (C) 2005 Junio C Hamano
+#
+# Applying diff between two trees to the work tree can be
+# done with the following single command:
+#
+# GIT_EXTERNAL_DIFF=git-apply-patch-script git-diff-tree -p $tree1 $tree2
+#
+
+case "$#" in
+2)    exit 1 ;; # do not feed unmerged diff to me!
+esac
+name="$1" tmp1="$2" hex1="$3" mode1="$4" tmp2="$5" hex2="$6" mode2="$7"
+case "$mode1" in *7??) mode1=+x ;; *6??) mode1=-x ;; esac
+case "$mode2" in *7??) mode2=+x ;; *6??) mode2=-x ;; esac
+
+if test -f "$name.orig" || test -f "$name.rej"
+then
+    echo >&2 "Unresolved patch conflicts in the previous run found."
+    exit 1
+fi
+# This will say "patching ..." so we do not say anything outselves.
+
+diff -u -L "a/$name" -L "b/$name" "$tmp1" "$tmp2" | patch -p1
+test -f "$name.rej" || {
+    case "$mode1,$mode2" in
+    .,?x)
+	# newly created
+	case "$mode2" in
+	+x)
+	    echo >&2 "created $name with mode +x."
+	    chmod "$mode2" "$name"
+	    ;;
+	-)
+	    echo >&2 "created $name."
+	    ;;
+	esac
+	git-update-cache --add -- "$name"
+	;;
+    ?x,.)
+	# deleted
+	echo >&2 "deleted $name."
+	rm -f "$name"
+	git-update-cache --remove -- "$name"
+	;;
+    *)
+	# changed
+	case "$mode1,$mode2" in
+	"$mode2,$mode1") ;;
+	*)
+	    echo >&2 "changing mode from $mode1 to $mode2."
+	    chmod "$mode2" "$name"
+	    ;;
+	esac
+    esac
+    # This bit is debatable---the SCM may not want to keep
+    # cache in sync with the work tree (JIT does want to).
+    git-update-cache -- "$name"
+}
+exit 0