test-dump-cache-tree: validate the cached data as well.

While dumping the cached data, try recomputing everything from
scratch to make sure things match.

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

dump-cache-tree.c

@@ -2,30 +2,64 @@
 #include "tree.h"
 #include "cache-tree.h"
 
-static void dump_cache_tree(struct cache_tree *it, const char *pfx)
+
+static void dump_one(struct cache_tree *it, const char *pfx, const char *x)
+{
+	if (it->entry_count < 0)
+		printf("%-40s %s%s (%d subtrees)\n",
+		       "invalid", x, pfx, it->subtree_nr);
+	else
+		printf("%s %s%s (%d entries, %d subtrees)\n",
+		       sha1_to_hex(it->sha1), x, pfx,
+		       it->entry_count, it->subtree_nr);
+}
+
+static int dump_cache_tree(struct cache_tree *it,
+			   struct cache_tree *ref,
+			   const char *pfx)
 {
 	int i;
+	int errs = 0;
+
 	if (!it)
 		return;
-	if (it->entry_count < 0)
-		printf("%-40s %s (%d subtrees)\n", "invalid", pfx,
-		       it->subtree_nr);
-	else
-		printf("%s %s (%d entries, %d subtrees)\n",
-		       sha1_to_hex(it->sha1),
-		       pfx, it->entry_count, it->subtree_nr);
+	if (!ref)
+		die("internal error");
+
+	if (it->entry_count < 0) {
+		dump_one(it, pfx, "");
+		dump_one(ref, pfx, "#(ref) ");
+		if (it->subtree_nr != ref->subtree_nr)
+			errs = 1;
+	}
+	else {
+		dump_one(it, pfx, "");
+		if (memcmp(it->sha1, ref->sha1, 20) ||
+		    ref->entry_count != it->entry_count ||
+		    ref->subtree_nr != it->subtree_nr) {
+			dump_one(ref, pfx, "#(ref) ");
+			errs = 1;
+		}
+	}
+
 	for (i = 0; i < it->subtree_nr; i++) {
 		char path[PATH_MAX];
 		struct cache_tree_sub *down = it->down[i];
+		struct cache_tree_sub *rdwn;
+
+		rdwn = cache_tree_sub(ref, down->name);
 		sprintf(path, "%s%.*s/", pfx, down->namelen, down->name);
-		dump_cache_tree(down->cache_tree, path);
+		if (dump_cache_tree(down->cache_tree, rdwn->cache_tree, path))
+			errs = 1;
 	}
+	return errs;
 }
 
 int main(int ac, char **av)
 {
+	struct cache_tree *another = cache_tree();
 	if (read_cache() < 0)
 		die("unable to read index file");
-	dump_cache_tree(active_cache_tree, "");
-	return 0;
+	cache_tree_update(another, active_cache, active_nr, 0, 1);
+	return dump_cache_tree(active_cache_tree, another, "");
 }