Added sanity checks. Fixed decoding_radius method arguments.

Author: jlavauzelle

src/sage/coding/extended_code.py

@@ -208,6 +208,9 @@ def __init__(self, code):
             sage: E
             Extended matrix-based encoder for Extended code coming from Linear code of length 11, dimension 5 over Finite Field of size 7
         """
+        if not isinstance(code, ExtendedCode):
+            raise TypeError("code has to be an instance of ExtendedCode class")
+
         super(ExtendedCodeExtendedMatrixEncoder, self).__init__(code)
 
     def _repr_(self):
@@ -329,6 +332,9 @@ def __init__(self, code, original_decoder = None, **kwargs):
             ...
             ValueError: Original decoder must have the original code as associated code
         """
+        if not isinstance(code, ExtendedCode):
+            raise TypeError("code has to be an instance of ExtendedCode class")
+
         original_code = code.original_code()
         if original_decoder is not None and not original_decoder.code() == original_code:
             raise ValueError("Original decoder must have the original code as associated code")
@@ -441,10 +447,15 @@ def decode_to_code(self, y, **kwargs):
             decoded_list.append(last_pos)
             return vector(F, decoded_list)
 
-    def decoding_radius(self, **kwargs):
+    def decoding_radius(self, *args, **kwargs):
         r"""
         Returns maximal number of errors that ``self`` can decode.
 
+        INPUT:
+        
+        - ``*args``, ``**kwargs`` -- arguments and optional arguments are
+          forwarded to original decoder's ``decoding_radius`` method.
+
         EXAMPLES::
 
             sage: C = codes.GeneralizedReedSolomonCode(GF(16, 'a').list()[:15], 7)
@@ -453,7 +464,7 @@ def decoding_radius(self, **kwargs):
             sage: D.decoding_radius()
             4
         """
-        return self.original_decoder().decoding_radius(**kwargs)
+        return self.original_decoder().decoding_radius(*args, **kwargs)
 
 
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