compat: Add simplified merge sort implementation from glibc

diff --git a/builtin-read-tree.c b/builtin-read-tree.c
index 41f81102380bf0ec86e223d393d0ab61b3f854ed..c0ea0342b755c6749391803d19f852182c0c512e 100644 (file)
--- a/builtin-read-tree.c
+++ b/builtin-read-tree.c
@@ -13,14 +13,20 @@
 #include "dir.h"
 #include "builtin.h"
 
-static struct object_list *trees;
+#define MAX_TREES 8
+static int nr_trees;
+static struct tree *trees[MAX_TREES];
 
 static int list_tree(unsigned char *sha1)
 {
-       struct tree *tree = parse_tree_indirect(sha1);
+       struct tree *tree;
+
+       if (nr_trees >= MAX_TREES)
+               die("I cannot read more than %d trees", MAX_TREES);
+       tree = parse_tree_indirect(sha1);
        if (!tree)
                return -1;
-       object_list_append(&tree->object, &trees);
+       trees[nr_trees++] = tree;
        return 0;
 }
 
@@ -76,11 +82,10 @@ static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
 
 static void prime_cache_tree(void)
 {
-       struct tree *tree = (struct tree *)trees->item;
-       if (!tree)
+       if (!nr_trees)
                return;
        active_cache_tree = cache_tree();
-       prime_cache_tree_rec(active_cache_tree, tree);
+       prime_cache_tree_rec(active_cache_tree, trees[0]);
 
 }
 
@@ -92,12 +97,12 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 {
        int i, newfd, stage = 0;
        unsigned char sha1[20];
+       struct tree_desc t[MAX_TREES];
        struct unpack_trees_options opts;
 
        memset(&opts, 0, sizeof(opts));
        opts.head_idx = -1;
 
-       setup_git_directory();
        git_config(git_default_config);
 
        newfd = hold_locked_index(&lock_file, 1);
@@ -259,7 +264,12 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
                        opts.head_idx = 1;
        }
 
-       unpack_trees(trees, &opts);
+       for (i = 0; i < nr_trees; i++) {
+               struct tree *tree = trees[i];
+               parse_tree(tree);
+               init_tree_desc(t+i, tree->buffer, tree->size);
+       }
+       unpack_trees(nr_trees, t, &opts);
 
        /*
         * When reading only one tree (either the most basic form,
@@ -267,13 +277,13 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
         * valid cache-tree because the index must match exactly
         * what came from the tree.
         */
-       if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
+       if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
                cache_tree_free(&active_cache_tree);
                prime_cache_tree();
        }
 
        if (write_cache(newfd, active_cache, active_nr) ||
-           close(newfd) || commit_locked_index(&lock_file))
+           commit_locked_index(&lock_file))
                die("unable to write new index file");
        return 0;
 }