🚀 go-pugleaf

I've encountered a couple of problems with file i/o on emacs
under VMS.  The problems occur during saving or auto-saving and
are related to protection modes.

I'm using Emacs 18.57 under VAX/VMS 5.1

NB: file protection is read as (system,owner,group,world), and I
am the owner of the files in the examples.


First problem:  if a file is protected against deletion, but not
writing, i.e.,

	$ dir yow.el/size/prot
	Directory DISK$USER1:[RBR4.EMACS.LISP]
	YOW.EL;1                  6  (RE,REW,RE,RE)
	Total of 1 files, 6 blocks.

then emacs reads in the file fine, and auto-saves are
correctly generated.  The problem comes when you try to save the
file.  I get the following message:

	IO error writing DISK$USER1:[RBR4.EMACS.LISP]YOW.EL: unknown error

I'm not yet sure as to the cause of this, but suspect something
with VAX C's emulation of unix modes.  Creating a file with write
privilege implies delete privilege, but here is a file that has
only write access.

The auto-save is not removed, it is left with the same
protection as the original.

	$ dir *yow.el*/size/prot
	Directory DISK$USER1:[RBR4.EMACS.LISP]
	YOW.EL;1                  6  (RE,REW,RE,RE)
	YOW.ELC;1                 3  (RE,REW,RE,RE)
	_$YOW.EL$;1               6  (RE,REW,RE,RE)
	Total of 3 files, 15 blocks.

Additionally there is an emergency save file $$save$$xxxxxx
written.



Second problem:  if the file is protected against both write and
delete, i.e.,

	$ dir yow.el/size/prot
	Directory DISK$USER1:[RBR4.EMACS.LISP]
	YOW.EL;1                  6  (RE,RE,RE,RE)
	Total of 1 files, 6 blocks.

then I get a message when auto-saving

	Auto-saving...error!for yow.el
	Auto-saving...done.

The result is:

	$ dir _$yow.el$/size/prot
	Directory DISK$USER1:[RBR4.EMACS.LISP]
	YOW.ELC;1                 0  (RE,RE,RE,RE)
	Total of 1 file, 0 blocks.

I think a more resonable behavior would be to change the
protection and write the auto-save file (if the directory
protection allows it).

If I now try to save the file I am prompted

	File yow.el is write-protected ; try to save anyway? (yes or no)

Answering yes results in the file being successfully saved, but
the auto-save file is not removed and the protection of the
previous version has been screwed up while the current version
has the same mode as the previous on had.

	$ dir *yow.el*/size/prot
	Directory DISK$USER1:[RBR4.EMACS.LISP]
	YOW.EL;2                  6  (RE,RE,RE,RE)
	YOW.EL;1                  6  (RWED,RWED,RWED,RWED)
	YOW.ELC;1                 3  (RE,RE,RE,RE)
	_$YOW.EL$;1               6  (RE,RE,RE,RE)
	Total of 4 files, 21 blocks.

This is definitely not a desirable state of affairs on VMS.  I
had started out with protected files to allow me to use the purge
command while keeping the originals.  Emacs unprotects the
originals and protects the modified versions.

roland
-- 
Roland Roberts,  University of Rochester   BITNET: roberts@uornsrl
  Nuclear Structure Research Lab         INTERNET: rbr4@uhura.cc.rochester.edu
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