Re: efs dis-integration with mule

`insert-file-contents-internal' is expected to use its `codesys' arg. This argument is normally created when `insert-file-contents' tries various ways of determining file coding system, including `insert-file-contents-pre-hook' call. `insert-file-contents-internal' may call filename hanlders obtained by `Ffind_file_name_handler (filename, Qinsert_file_contents)' call. Such handlers are established by remote file access packages like efs. In this case the `handler' call replaces most of processing normally done by `insert-file-contents-internal' itself, including that of `codesys'. But this argument is never passed to `handler' and thus discarded.

Handler may even call `insert-file-contents' recursively, which in turn will trigger file coding determining again, with `insert-file-contents-pre-hook' call. So many unnecessary `insert-file-contents-pre-hook' calls may be done on the same file. There may be 2 of them if both efs and dired are loaded. This complicates `insert-file-contents-pre-hook' functions which do some expensive processing. [...]