git-branch -D: make it work even when on a yet-to-be-born branch

diff --git a/diffcore-order.c b/diffcore-order.c
index a03862c1ce73995065bf838b408e8a6d9396025b..aef6da60447b98a05d91513b4aa74e505b0a0d84 100644 (file)
--- a/diffcore-order.c
+++ b/diffcore-order.c
@@ -28,9 +28,9 @@ static void prepare_order(const char *orderfile)
        }
        map = mmap(NULL, st.st_size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
        close(fd);
-       if (-1 == (int)(long)map)
+       if (map == MAP_FAILED)
                return;
-       endp = map + st.st_size;
+       endp = (char *) map + st.st_size;
        for (pass = 0; pass < 2; pass++) {
                cnt = 0;
                cp = map;
@@ -105,9 +105,13 @@ static int compare_pair_order(const void *a_, const void *b_)
 void diffcore_order(const char *orderfile)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
-       struct pair_order *o = xmalloc(sizeof(*o) * q->nr);
+       struct pair_order *o;
        int i;
 
+       if (!q->nr)
+               return;
+
+       o = xmalloc(sizeof(*o) * q->nr);
        prepare_order(orderfile);
        for (i = 0; i < q->nr; i++) {
                o[i].pair = q->queue[i];