Bug#13510 "Setting password local variable changes current

password": additional fix, also make sure that a syntax error is 
returned for set names="foo" when there is no such variable or no
stored procedure.

mysql-test/t/sp-error.test

@@ -1233,6 +1233,10 @@ begin
   select password;
 end|
 
+# Check that an error message is sent
+--error ER_PARSE_ERROR
+set names='foo2'|
+
 --error ER_SP_BAD_VAR_SHADOW
 create procedure bug13510_2()
 begin