tree-diff: allow diff_tree_sha1 to accept NULL sha1

diff --git a/commit.c b/commit.c
index b9f9838110b4703a387fa256a138eff74b61589c..6bf4fe00d4b0365eca75fd9988852650660b6884 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -841,26 +841,26 @@ static struct commit_list *merge_bases_many(struct commit *one, int n, struct co
 struct commit_list *get_octopus_merge_bases(struct commit_list *in)
 {
        struct commit_list *i, *j, *k, *ret = NULL;
-       struct commit_list **pptr = &ret;
 
-       for (i = in; i; i = i->next) {
-               if (!ret)
-                       pptr = &commit_list_insert(i->item, pptr)->next;
-               else {
-                       struct commit_list *new = NULL, *end = NULL;
-
-                       for (j = ret; j; j = j->next) {
-                               struct commit_list *bases;
-                               bases = get_merge_bases(i->item, j->item, 1);
-                               if (!new)
-                                       new = bases;
-                               else
-                                       end->next = bases;
-                               for (k = bases; k; k = k->next)
-                                       end = k;
-                       }
-                       ret = new;
+       if (!in)
+               return ret;
+
+       commit_list_insert(in->item, &ret);
+
+       for (i = in->next; i; i = i->next) {
+               struct commit_list *new = NULL, *end = NULL;
+
+               for (j = ret; j; j = j->next) {
+                       struct commit_list *bases;
+                       bases = get_merge_bases(i->item, j->item, 1);
+                       if (!new)
+                               new = bases;
+                       else
+                               end->next = bases;
+                       for (k = bases; k; k = k->next)
+                               end = k;
                }
+               ret = new;
        }
        return ret;
 }