Update git-diff-script.

This uses the fixed rev-parse to allow passing diff options to the
underlying diff command.  For example:

    $ git diff -r HEAD

shows the output in raw-diff format, and

    $ git diff -p -R HEAD | git apply

generates a patch to go back from your working tree to HEAD commit
(i.e. an expensive way to say "git checkout -f HEAD").

At the same time, it accidentally removes the use of shell arrays.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-diff-script b/git-diff-script
index 99ff264..a285a2a 100755 (executable)
--- a/git-diff-script
+++ b/git-diff-script
@@ -1,23 +1,35 @@
 #!/bin/sh
-rev=($(git-rev-parse --revs-only "$@")) || exit
-flags=($(git-rev-parse --no-revs --flags "$@"))
-files=($(git-rev-parse --no-revs --no-flags "$@"))
-case "${#rev[*]}" in
-0)
-       git-diff-files -M -p "$@";;
-1)
-       git-diff-cache -M -p "$@";;
-2)
-       case "${rev[1]}" in
-       ^?*)
-               begin=$(echo "${rev[1]}" | tr -d '^')
-               end="${rev[0]}" ;;
-       *)
-               begin="${rev[0]}"
-               end="${rev[1]}" ;;
-       esac
-       git-diff-tree -M -p $flags $begin $end $files;;
+#
+# Copyright (c) 2005 Linus Torvalds
+# Copyright (c) 2005 Junio C Hamano
+
+rev=$(git-rev-parse --revs-only --no-flags --sq "$@") || exit
+flags=$(git-rev-parse --no-revs --flags --sq "$@")
+files=$(git-rev-parse --no-revs --no-flags --sq "$@")
+
+: ${flags:="'-M' '-p'"}
+
+case "$rev" in
+?*' '?*' '?*)
+       die "I don't understand"
+       ;;
+?*' '^?*)
+       begin=$(expr "$rev" : '.*^.\([0-9a-f]*\).*') &&
+       end=$(expr "$rev" : '.\([0-9a-f]*\). .*') || exit
+       cmd="git-diff-tree $flags $begin $end $files"
+       ;;
+?*' '?*)
+       cmd="git-diff-tree $flags $rev $files"
+       ;;
+?*' ')
+       cmd="git-diff-cache $flags $rev $files"
+       ;;
+'')
+       cmd="git-diff-files $flags $files"
+       ;;
 *)
-       echo "I don't understand"
-       exit 1;;
+       die "I don't understand $*"
+       ;;
 esac
+
+eval "$cmd"