Fix dereference of freed delta

I was accidentally using a value that I had just freed.  This
moves the clearing of the delta internal flags into a better place.

src/diff_tform.c

@@ -18,6 +18,7 @@ static git_diff_delta *diff_delta__dup(
 		return NULL;
 
 	memcpy(delta, d, sizeof(git_diff_delta));
+	GIT_DIFF_FLAG__CLEAR_INTERNAL(delta->flags);
 
 	if (d->old_file.path != NULL) {
 		delta->old_file.path = git_pool_strdup(pool, d->old_file.path);
@@ -361,21 +362,25 @@ static int apply_splits_and_deletes(
 			delta->old_file.flags |= GIT_DIFF_FLAG_VALID_OID;
 		}
 
+		/* clean up delta before inserting into new list */
+		GIT_DIFF_FLAG__CLEAR_INTERNAL(delta->flags);
+
+		if (delta->status != GIT_DELTA_COPIED &&
+			delta->status != GIT_DELTA_RENAMED &&
+			(delta->status != GIT_DELTA_MODIFIED || actually_split))
+			delta->similarity = 0;
+
+		/* insert into new list */
 		if (git_vector_insert(&onto, delta) < 0)
 			goto on_error;
 	}
 
 	/* cannot return an error past this point */
+
+	/* free deltas from old list that didn't make it to the new one */
 	git_vector_foreach(&diff->deltas, i, delta) {
 		if ((delta->flags & GIT_DIFF_FLAG__TO_DELETE) != 0)
 			git__free(delta);
-
-		GIT_DIFF_FLAG__CLEAR_INTERNAL(delta->flags);
-
-		if (delta->status != GIT_DELTA_COPIED &&
-			delta->status != GIT_DELTA_RENAMED &&
-			(delta->status != GIT_DELTA_MODIFIED || actually_split))
-			delta->similarity = 0;
 	}
 
 	/* swap new delta list into place */