The fftw distributor now uses (x, 1) instead of (x,) as inference shape for...

The fftw distributor now uses (x, 1) instead of (x,) as inference shape for one-dimensional arrays (important for ffts).

d2o/distributor_factory.py

@@ -2028,6 +2028,9 @@ if 'pyfftw' in gdi:
         if np.any(mask):
             working_shape[mask] = 1
 
+        if len(working_shape) == 1:
+            working_shape = tuple(working_shape) + (1,)
+
         local_size = pyfftw.local_size(working_shape, comm=comm)
         start = local_size[2]
         end = start + local_size[1]