googleapis
diff --git a/Collapse file
‎packages/gapic-generator/gapic/schema/wrappers.py‎
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+2-1Lines changed: 2 additions & 1 deletion b/Collapse file
‎packages/gapic-generator/gapic/schema/wrappers.py‎
Copy file name to clipboardExpand all lines: packages/gapic-generator/gapic/schema/wrappers.py
+2-1Lines changed: 2 additions & 1 deletion
diff --git a/Collapse file
‎packages/gapic-generator/tests/unit/schema/wrappers/test_method.py‎
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+8Lines changed: 8 additions & 0 deletions b/Collapse file
‎packages/gapic-generator/tests/unit/schema/wrappers/test_method.py‎
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+8Lines changed: 8 additions & 0 deletions
@@ -555,7 +555,8 @@ def flattened_fields(self) -> Mapping[str, Field]:
         answer: Dict[str, Field] = collections.OrderedDict(
             (f.strip(), self.input.get_field(*f.strip().split('.')))
             for sig in signatures
-            for f in sig.split(',')
+            # Special case for an empty signature check
+            for f in sig.split(',') if f
         )
 
         return answer
 
@@ -171,6 +171,14 @@ def test_method_flattened_fields():
     assert 'b' in method.flattened_fields
 
 
+def test_method_flattened_fields_empty_sig():
+    a = make_field('a', type=5)  # int
+    b = make_field('b', type=5)
+    input_msg = make_message('Z', fields=(a, b))
+    method = make_method('F', input_message=input_msg, signatures=('',))
+    assert len(method.flattened_fields) == 0
+
+
 def test_method_include_flattened_message_fields():
     a = make_field('a', type=5)
     b = make_field('b', type=11, message=make_message('Eggs'))