Merge pull request #7380 from Cadair/units/quantity-nan

v2.0.x : Fix None return annotation in quantity_input

astropy/units/decorators.py

@@ -221,7 +221,7 @@ def wrapper(*func_args, **func_kwargs):
             # Call the original function with any equivalencies in force.
             with add_enabled_equivalencies(self.equivalencies):
                 return_ = wrapped_function(*func_args, **func_kwargs)
-            if wrapped_signature.return_annotation is not funcsigs.Signature.empty:
+            if wrapped_signature.return_annotation not in (funcsigs.Signature.empty, None):
                 return return_.to(wrapped_signature.return_annotation)
             else:
                 return return_

astropy/units/tests/py3_test_quantity_annotations.py

@@ -289,3 +289,14 @@ def myfunc_args(solarx: u.arcsec) -> u.deg:
     assert solarx.unit is u.deg
     """
     return src
+
+def test_return_annotation_none():
+    src = """
+    @u.quantity_input
+    def myfunc_args(solarx: u.arcsec) -> None:
+        pass
+
+    solarx = myfunc_args(1*u.arcsec)
+    assert solarx is None
+    """
+    return src