py/bc: Fix checking for duplicate **kwargs.

The code was already checking for duplicate kwargs for named parameters but
if `**kwargs` was given as a parameter, it did not check for multiples of
the same argument name.

This fixes the issue by adding an addition test to catch duplicates and
adds a test to exercise the code.

Fixes issue #10083.

Signed-off-by: David Lechner <david@pybricks.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/tests/basics/fun_calldblstar.py b/tests/basics/fun_calldblstar.py
index 4a503698f..0308f42bd 100644
--- a/tests/basics/fun_calldblstar.py
+++ b/tests/basics/fun_calldblstar.py
@@ -20,3 +20,13 @@ class A:
 a = A()
 a.f(1, **{'b':2})
 a.f(1, **{'b':val for val in range(1)})
+
+# test for duplicate keys in **kwargs not allowed
+
+def f1(**kwargs):
+    print(kwargs)
+
+try:
+    f1(**{'a': 1, 'b': 2}, **{'b': 3, 'c': 4})
+except TypeError:
+    print('TypeError')