commit-tree: lift completely arbitrary limit of 16 parents

There is no really good reason to have a merge with more than 16
parents, but we have a history of giving our users rope.

Combined with the fact that there was no good reason for that
arbitrary limit in the first place, here is an all-too-easy to fix.

Kind of wished-for by Len Brown.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-commit-tree.c b/builtin-commit-tree.c
index e5e4bdbe862b23aafe932da411f597b0f3b5c997..3881f6c2f56f317726a688e44b98806987036999 100644 (file)
--- a/builtin-commit-tree.c
+++ b/builtin-commit-tree.c
@@ -24,26 +24,20 @@ static void check_valid(unsigned char *sha1, enum object_type expect)
                    typename(expect));
 }
 
-/*
- * Having more than two parents is not strange at all, and this is
- * how multi-way merges are represented.
- */
-#define MAXPARENT (16)
-static unsigned char parent_sha1[MAXPARENT][20];
-
 static const char commit_tree_usage[] = "git-commit-tree <sha1> [-p <sha1>]* < changelog";
 
-static int new_parent(int idx)
+static void new_parent(struct commit *parent, struct commit_list **parents_p)
 {
-       int i;
-       unsigned char *sha1 = parent_sha1[idx];
-       for (i = 0; i < idx; i++) {
-               if (!hashcmp(parent_sha1[i], sha1)) {
+       unsigned char *sha1 = parent->object.sha1;
+       struct commit_list *parents;
+       for (parents = *parents_p; parents; parents = parents->next) {
+               if (parents->item == parent) {
                        error("duplicate parent %s ignored", sha1_to_hex(sha1));
-                       return 0;
+                       return;
                }
+               parents_p = &parents->next;
        }
-       return 1;
+       commit_list_insert(parent, parents_p);
 }
 
 static const char commit_utf8_warn[] =
@@ -54,7 +48,7 @@ static const char commit_utf8_warn[] =
 int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 {
        int i;
-       int parents = 0;
+       struct commit_list *parents = NULL;
        unsigned char tree_sha1[20];
        unsigned char commit_sha1[20];
        struct strbuf buffer;
@@ -69,18 +63,16 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 
        check_valid(tree_sha1, OBJ_TREE);
        for (i = 2; i < argc; i += 2) {
+               unsigned char sha1[20];
                const char *a, *b;
                a = argv[i]; b = argv[i+1];
                if (!b || strcmp(a, "-p"))
                        usage(commit_tree_usage);
 
-               if (parents >= MAXPARENT)
-                       die("Too many parents (%d max)", MAXPARENT);
-               if (get_sha1(b, parent_sha1[parents]))
+               if (get_sha1(b, sha1))
                        die("Not a valid object name %s", b);
-               check_valid(parent_sha1[parents], OBJ_COMMIT);
-               if (new_parent(parents))
-                       parents++;
+               check_valid(sha1, OBJ_COMMIT);
+               new_parent(lookup_commit(sha1), &parents);
        }
 
        /* Not having i18n.commitencoding is the same as having utf-8 */
@@ -94,8 +86,13 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
         * different order of parents will be a _different_ changeset even
         * if everything else stays the same.
         */
-       for (i = 0; i < parents; i++)
-               strbuf_addf(&buffer, "parent %s\n", sha1_to_hex(parent_sha1[i]));
+       while (parents) {
+               struct commit_list *next = parents->next;
+               strbuf_addf(&buffer, "parent %s\n",
+                       sha1_to_hex(parents->item->object.sha1));
+               free(parents);
+               parents = next;
+       }
 
        /* Person/date information */
        strbuf_addf(&buffer, "author %s\n", git_author_info(IDENT_ERROR_ON_NO_NAME));