Add test-dump-cache-tree

This was useful in diagnosing the corrupt index.aux format
problem.  But do not bother building or installing it by
default.

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

.gitignore

@@ -123,6 +123,7 @@ git-write-tree
 git-core-*/?*
 test-date
 test-delta
+test-dump-cache-tree
 common-cmds.h
 *.tar.gz
 *.dsc

Makefile

@@ -611,6 +611,9 @@ test-date$X: test-date.c date.o ctype.o
 test-delta$X: test-delta.c diff-delta.o patch-delta.o
 	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $^ -lz
 
+test-dump-cache-tree$X: dump-cache-tree.o $(GITLIBS)
+	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) $(LIBS)
+
 check:
 	for i in *.c; do sparse $(ALL_CFLAGS) $(SPARSE_FLAGS) $$i || exit; done
 

dump-cache-tree.c

@@ -0,0 +1,32 @@
+#include "cache.h"
+#include "tree.h"
+#include "cache-tree.h"
+
+static unsigned char active_cache_sha1[20];
+static struct cache_tree *active_cache_tree;
+
+static void dump_cache_tree(struct cache_tree *it, const char *pfx)
+{
+	int i;
+	if (it->entry_count < 0)
+		printf("%-40s %s\n", "invalid", pfx);
+	else
+		printf("%s %s (%d entries)\n",
+		       sha1_to_hex(it->sha1),
+		       pfx, it->entry_count);
+	for (i = 0; i < it->subtree_nr; i++) {
+		char path[PATH_MAX];
+		struct cache_tree_sub *down = it->down[i];
+		sprintf(path, "%s%.*s/", pfx, down->namelen, down->name);
+		dump_cache_tree(down->cache_tree, path);
+	}
+}
+
+int main(int ac, char **av)
+{
+	if (read_cache_1(active_cache_sha1) < 0)
+		die("unable to read index file");
+	active_cache_tree = read_cache_tree(active_cache_sha1);
+	dump_cache_tree(active_cache_tree, "");
+	return 0;
+}