error message in CALL-NEXT-METHOD

[<ha...@il...>]

Hi,

I made a change to improve the error message in a particular case of 
CALL-NEXT-METHOD. Before the change this code

(defgeneric foo (x)
       (:method ((x (eql 0))) (call-next-method 1))
       (:method ((x (eql 1))) (* 10 x)))
(foo 0)

gave

*** - NO-NEXT-METHOD: When calling #<GENERIC-FUNCTION FOO> with arguments (1), 
there is no next method after #<STANDARD-METHOD ((EQL 0))>, and 
(CALL-NEXT-METHOD) was called.

Now it gives

*** - CALL-NEXT-METHOD in #<GENERIC-FUNCTION FOO>: the new arguments (1) have 
a different effective method than the old arguments (0)

Note that in a different case

(defgeneric foo (x)
       (:method ((x (eql 0))) (call-next-method 1))
       (:method ((x integer)) (* 10 x)))
#<GENERIC-FUNCTION FOO>
(foo 0)

the error message was already the right one.

Bruno