merge-tool documentation: describe custom command usage

diff --git a/builtin-write-tree.c b/builtin-write-tree.c
index 88f34ba7d6e2426fae5169eb28b12e93e72082eb..e838d01233eb1d6cfaa0885c6b37c8726079b0ac 100644 (file)
--- a/builtin-write-tree.c
+++ b/builtin-write-tree.c
@@ -11,67 +11,14 @@
 static const char write_tree_usage[] =
 "git-write-tree [--missing-ok] [--prefix=<prefix>/]";
 
-int write_tree(unsigned char *sha1, int missing_ok, const char *prefix)
-{
-       int entries, was_valid, newfd;
-
-       /* We can't free this memory, it becomes part of a linked list parsed atexit() */
-       struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
-
-       newfd = hold_locked_index(lock_file, 1);
-
-       entries = read_cache();
-       if (entries < 0)
-               die("git-write-tree: error reading cache");
-
-       if (!active_cache_tree)
-               active_cache_tree = cache_tree();
-
-       was_valid = cache_tree_fully_valid(active_cache_tree);
-
-       if (!was_valid) {
-               if (cache_tree_update(active_cache_tree,
-                                     active_cache, active_nr,
-                                     missing_ok, 0) < 0)
-                       die("git-write-tree: error building trees");
-               if (0 <= newfd) {
-                       if (!write_cache(newfd, active_cache, active_nr)
-                                       && !close(newfd)) {
-                               commit_lock_file(lock_file);
-                               newfd = -1;
-                       }
-               }
-               /* Not being able to write is fine -- we are only interested
-                * in updating the cache-tree part, and if the next caller
-                * ends up using the old index with unupdated cache-tree part
-                * it misses the work we did here, but that is just a
-                * performance penalty and not a big deal.
-                */
-       }
-
-       if (prefix) {
-               struct cache_tree *subtree =
-                       cache_tree_find(active_cache_tree, prefix);
-               if (!subtree)
-                       die("git-write-tree: prefix %s not found", prefix);
-               hashcpy(sha1, subtree->sha1);
-       }
-       else
-               hashcpy(sha1, active_cache_tree->sha1);
-
-       if (0 <= newfd)
-               close(newfd);
-       rollback_lock_file(lock_file);
-
-       return 0;
-}
-
 int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
 {
        int missing_ok = 0, ret;
        const char *prefix = NULL;
        unsigned char sha1[20];
+       const char *me = "git-write-tree";
 
+       git_config(git_default_config);
        while (1 < argc) {
                const char *arg = argv[1];
                if (!strcmp(arg, "--missing-ok"))
@@ -86,8 +33,20 @@ int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
        if (argc > 2)
                die("too many options");
 
-       ret = write_tree(sha1, missing_ok, prefix);
-       printf("%s\n", sha1_to_hex(sha1));
-
+       ret = write_cache_as_tree(sha1, missing_ok, prefix);
+       switch (ret) {
+       case 0:
+               printf("%s\n", sha1_to_hex(sha1));
+               break;
+       case WRITE_TREE_UNREADABLE_INDEX:
+               die("%s: error reading the index", me);
+               break;
+       case WRITE_TREE_UNMERGED_INDEX:
+               die("%s: error building trees; the index is unmerged?", me);
+               break;
+       case WRITE_TREE_PREFIX_ERROR:
+               die("%s: prefix %s not found", me, prefix);
+               break;
+       }
        return ret;
 }