Invalidate cache-tree entries for touched paths in git-apply.

This updates git-apply to maintain cache-tree information.  With
this and the previous write-tree patch, repeated "apply --index"
followed by "write-tree" on a huge tree will hopefully become
faster.

Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/apply.c b/apply.c
index 269210a..e283df3 100644
--- a/apply.c
+++ b/apply.c
@@ -8,9 +8,14 @@
  */
 #include <fnmatch.h>
 #include "cache.h"
+#include "cache-tree.h"
 #include "quote.h"
 #include "blob.h"
 
+static unsigned char active_cache_sha1[20];
+static struct cache_tree *active_cache_tree;
+
+
 //  --check turns on checking that the working tree matches the
 //    files that are being modified, but doesn't apply the patch
 //  --stat does just a diffstat, and doesn't actually apply
@@ -1717,6 +1722,7 @@
 	if (write_index) {
 		if (remove_file_from_cache(patch->old_name) < 0)
 			die("unable to remove %s from index", patch->old_name);
+		cache_tree_invalidate_path(active_cache_tree, patch->old_name);
 	}
 	unlink(patch->old_name);
 }
@@ -1813,8 +1819,9 @@
 
 	if (!mode)
 		mode = S_IFREG | 0644;
-	create_one_file(path, mode, buf, size);	
+	create_one_file(path, mode, buf, size);
 	add_index_file(path, mode, buf, size);
+	cache_tree_invalidate_path(active_cache_tree, path);
 }
 
 static void write_out_one_result(struct patch *patch)
@@ -1912,8 +1919,9 @@
 	if (write_index)
 		newfd = hold_index_file_for_update(&cache_file, get_index_file());
 	if (check_index) {
-		if (read_cache() < 0)
+		if (read_cache_1(active_cache_sha1) < 0)
 			die("unable to read index file");
+		active_cache_tree = read_cache_tree(active_cache_sha1);
 	}
 
 	if ((check || apply) && check_patch_list(list) < 0)
@@ -1923,9 +1931,11 @@
 		write_out_results(list, skipped_patch);
 
 	if (write_index) {
-		if (write_cache(newfd, active_cache, active_nr) ||
+		if (write_cache_1(newfd, active_cache, active_nr,
+				  active_cache_sha1) ||
 		    commit_index_file(&cache_file))
 			die("Unable to write new cachefile");
+		write_cache_tree(active_cache_sha1, active_cache_tree);
 	}
 
 	if (show_index_info)