Fix #1767

Cython/Compiler/Nodes.py

@@ -3621,10 +3621,12 @@ class DefNodeWrapper(FuncDefNode):
                 reversed_args = list(enumerate(positional_args))[::-1]
                 for i, arg in reversed_args:
                     if i >= min_positional_args-1:
+                        if i != reversed_args[0][0]:
+                            code.putln('CYTHON_FALLTHROUGH;')
                         code.put('case %2d: ' % (i+1))
                     code.putln("values[%d] = PyTuple_GET_ITEM(%s, %d);" % (i, Naming.args_cname, i))
-                    code.putln('CYTHON_FALLTHROUGH;')
                 if min_positional_args == 0:
+                    code.putln('CYTHON_FALLTHROUGH;')
                     code.put('case  0: ')
                 code.putln('break;')
                 if self.star_arg:
@@ -3781,6 +3783,8 @@ class DefNodeWrapper(FuncDefNode):
                     if self.star_arg and i == max_positional_args:
                         code.putln('default:')
                     else:
+                        if i != 0:
+                            code.putln('CYTHON_FALLTHROUGH;')
                         code.putln('case %2d:' % i)
                 pystring_cname = code.intern_identifier(arg.name)
                 if arg.default:
@@ -3819,8 +3823,6 @@ class DefNodeWrapper(FuncDefNode):
                             self.name, pystring_cname))
                         code.putln(code.error_goto(self.pos))
                         code.putln('}')
-                if max_positional_args > 0 and i < last_required_arg:
-                    code.putln('CYTHON_FALLTHROUGH;')
             if max_positional_args > 0:
                 code.putln('}')