Fix handling of duplicates in docstrings.

Author: domdfcoding

flake8_params/__init__.py

@@ -124,7 +124,7 @@ def check_params(
 	docstring_set = set(docstring_args)
 	if signature_set == docstring_set:
 		# Wrong order or duplicated
-		docstring_counts = {k: v for k, v in Counter(docstring_set).items() if v > 1}
+		docstring_counts = {k: v for k, v in Counter(docstring_args).items() if v > 1}
 
 		if docstring_counts:
 			return PRM003 + ": " + ' '.join(sorted(docstring_counts.keys()))

tests/test_flake8_params_/test_plugin.txt

@@ -19,4 +19,4 @@
 311:0: PRM002 Missing parameters in docstring: **baz
 356:1: PRM002 Missing parameters in docstring: a b c
 372:1: PRM002 Missing parameters in docstring: swallow
-404:0: PRM001 Docstring parameters in wrong order.
+404:0: PRM003 Extra parameters in docstring: tree