calling convention for file-coding-system-alist functions

Hello, I have a question about the functions which can be used in file-coding-system-alist lists. After executing | (modify-coding-system-alist 'file "\\.po" 'my-func) and opening a file `test.po', `my-func' gets called by code-files.el:168 as | (setq codesys (funcall codesys 'insert-file-contents filename)) resulting in | ... (my-func 'insert-file-contents filename) This call differs from this one which would be done by GNU Emacs. There the `find-operation-coding-system' function is responsible whose documentation is saying | This function looks up what specified for TARGET in, | `file-coding-system-alist', [...] depending on OPERATION. They may | specify [...] a function symbol to call. | In the last case, we call the function with one argument, which is a | list of all the arguments given to this function. Therefore in GNU Emacs `my-func' would be called as | ... (my-func '('insert-file-contents filename)) Has the syntax of coding-system-alist functions been changed in XEmacs or is code-files.el erroneous? Enrico