bugfix: check for NULL before testing isPartiallyFull(stp->blocks)

diff --git a/rts/sm/GC.c b/rts/sm/GC.c
index af35150..244da13 100644 (file)
--- a/rts/sm/GC.c
+++ b/rts/sm/GC.c
@@ -1237,7 +1237,7 @@ init_uncollected_gen (nat g, nat threads)
 
            // If the block at the head of the list in this generation
            // is less than 3/4 full, then use it as a todo block.
-           if (isPartiallyFull(stp->blocks))
+           if (stp->blocks && isPartiallyFull(stp->blocks))
            {
                ws->todo_bd = stp->blocks;
                 ws->todo_free = ws->todo_bd->free;