Fixes for chunks with zeros

Author: lshaw8317

src/blosc2/lazyexpr.py

@@ -3148,7 +3148,8 @@ def __init__(self, func, inputs, dtype, shape=None, chunked_eval=True, **kwargs)
 
         self.res_getitem = blosc2.empty(self._shape, self._dtype, **kwargs_getitem)
         # Register a postfilter for getitem
-        self.res_getitem._set_postf_udf(self.func, id(self.inputs))
+        if 0 not in self._shape:
+            self.res_getitem._set_postf_udf(self.func, id(self.inputs))
 
         self.inputs_dict = {f"o{i}": obj for i, obj in enumerate(self.inputs)}
 

src/blosc2/ndarray.py

@@ -314,7 +314,7 @@ def reshape(
     # Create the new array
     dst = empty(shape, dtype=src.dtype, **kwargs)
 
-    if is_inside_new_expr():
+    if is_inside_new_expr() or 0 in shape:
         # We already have the dtype and shape, so return immediately
         return dst
 
@@ -1679,7 +1679,7 @@ def __getitem__(  # noqa: C901
             return expr.where(self)
 
         key_ = (key,) if not isinstance(key, tuple) else key
-        key_ = tuple(k[:] if isinstance(k, NDArray) else k for k in key_)  # decompress NDArrays
+        key_ = tuple(k[()] if isinstance(k, NDArray) else k for k in key_)  # decompress NDArrays
         key_, mask = process_key(key_, self.shape)  # internally handles key an integer
 
         if builtins.any(isinstance(k, (list, np.ndarray)) for k in key_):