Handle 0 shape arrays too

Author: lshaw8317

blosc/b2nd.c

@@ -616,6 +616,11 @@ int b2nd_get_slice_nchunks(const b2nd_array_t *array, const int64_t *start, cons
 
   int8_t ndim = array->ndim;
 
+  if (array->nitems == 0){  
+    *chunks_idx = malloc(0);
+    return 0;
+  }
+
   // 0-dim case
   if (ndim == 0) {
     *chunks_idx = malloc(1 * sizeof(int64_t));