diff 'rename' format change.

Clearly even Junio felt git "rename" header lines should say "from/to"
instead of "old/new", since he wrote the documentation that way.

This way it also matches "copy".

git-apply will accept both versions, at least for a while.

apply.c

@@ -437,6 +437,8 @@ static int parse_git_header(char *line, int len, unsigned int size, struct patch
 			{ "copy to ", gitdiff_copydst },
 			{ "rename old ", gitdiff_renamesrc },
 			{ "rename new ", gitdiff_renamedst },
+			{ "rename from ", gitdiff_renamesrc },
+			{ "rename to ", gitdiff_renamedst },
 			{ "similarity index ", gitdiff_similarity },
 			{ "dissimilarity index ", gitdiff_dissimilarity },
 			{ "", gitdiff_unrecognized },

diff.c

@@ -786,8 +786,8 @@ static void diff_flush_patch(struct diff_filepair *p)
 	case 'R':
 		sprintf(msg_,
 			"similarity index %d%%\n"
-			"rename old %s\n"
-			"rename new %s",
+			"rename from %s\n"
+			"rename to %s",
 			(int)(0.5 + p->score * 100.0/MAX_SCORE),
 			p->one->path, p->two->path);
 		msg = msg_;

t/t4001-diff-rename.sh

@@ -44,8 +44,8 @@ test_expect_success \
     'git-diff-cache -p -M $tree >current'
 cat >expected <<\EOF
 diff --git a/path0 b/path1
-rename old path0
-rename new path1
+rename from path0
+rename to path1
 --- a/path0
 +++ b/path1
 @@ -8,7 +8,7 @@ Line 7

t/t4003-diff-rename-1.sh

@@ -40,8 +40,8 @@ copy to COPYING.1
 - HOWEVER, in order to allow a migration to GPLv3 if that seems like
 + However, in order to allow a migration to GPLv3 if that seems like
 diff --git a/COPYING b/COPYING.2
-rename old COPYING
-rename new COPYING.2
+rename from COPYING
+rename to COPYING.2
 --- a/COPYING
 +++ b/COPYING.2
 @@ -2 +2 @@

t/t4004-diff-rename-symlink.sh

@@ -48,8 +48,8 @@ copy from frotz
 copy to nitfol
 diff --git a/frotz b/rezrov
 similarity index 100%
-rename old frotz
-rename new rezrov
+rename from frotz
+rename to rezrov
 diff --git a/yomin b/yomin
 deleted file mode 100644
 --- a/yomin

t/t4005-diff-rename-2.sh

@@ -53,8 +53,8 @@ copy to COPYING.1
 - HOWEVER, in order to allow a migration to GPLv3 if that seems like
 + However, in order to allow a migration to GPLv3 if that seems like
 diff --git a/COPYING b/COPYING.2
-rename old COPYING
-rename new COPYING.2
+rename from COPYING
+rename to COPYING.2
 --- a/COPYING
 +++ b/COPYING.2
 @@ -2 +2 @@

t/t4009-diff-rename-4.sh

@@ -57,8 +57,8 @@ copy to COPYING.1
 - HOWEVER, in order to allow a migration to GPLv3 if that seems like
 + However, in order to allow a migration to GPLv3 if that seems like
 diff --git a/COPYING b/COPYING.2
-rename old COPYING
-rename new COPYING.2
+rename from COPYING
+rename to COPYING.2
 --- a/COPYING
 +++ b/COPYING.2
 @@ -2 +2 @@