auto-save fails sometimes

[Robert Moniot]

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Please write in English, because the Emacs maintainers do not have
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In GNU Emacs 20.7.1 (i386-redhat-linux-gnu, X toolkit)
 of Tue Jun 13 2000 on porky.devel.redhat.com
configured using `configure  --mandir=/usr/man --infodir=/usr/info 
--prefix=/usr --libexecdir=/usr/lib --sharedstatedir=/var --with-gcc --with-pop 
--with-x-toolkit i386-redhat-linux-gnu'

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:


First, the environment in which this is happening: I am using rmail to
read mail that is initially in file ~/RMAIL.

After being read, mail messages are filed in various rmail files in
directory ~/Mail.

pascal:~/$ ls -ld Mail
drwxr-x---   11 moniot   staff        4096 Jan  2 15:06 Mail/

The particular rmail file in this case is in a subdirectory Classes.

pascal:~/$ ls -ld Mail/Classes
drwxr-xr-x    2 moniot   staff        1024 Jan  3 18:26 Mail/Classes/

The file itself is named switching.

pascal:~/$ ls -l Mail/Classes/switching
-rw-r--r--    1 moniot   staff      408300 Jan  3 17:25 Mail/Classes/switching

The steps that produced the bug:
  1. read a message in RMAIL (using M-x rmail).
  2. save the message (using o) into ~/Mail/Classes/switching
  3. read the switching rmail file (using rmail-input
     ~/Mail/Classes/switching or, later, simply C-x b switching).
  4. Move to a different message in the switching rmail file (using p
     or n).  (Presumably this causes the buffer to need auto-saving.)
  5. go back to RMAIL (using C-x b RMAIL)
  6. wait till time-out causes auto-save to run.  (The switch to
     *Messages* buffer at the end of "Recent input" was to make sure
     the bug had happened.)

The bug happens for other files too, in similar circumstances.  I
think it has happened while in other modes than rmail-mode.  One
essential requirement seems to be that the file to be auto-saved is in
a directory tree that is not world-readable.  At least, I do not
recall ever seeing the bug happen for any file that is in a
world-readable directory.



Recent input:
y SPC f o r SPC m a i l SPC b u f f e r s . return 
C-x b return o M-backspace S y s SPC l i n SPC return 
d n n o return d C-x b U M backspace backspace * M 
SPC return down-mouse-1 mouse-1 menu-bar buffer "RMAIL" 
g o M-backspace C l a SPC s w i SPC return d o return 
d C-x b s w i SPC return n n C-x b return C-x b U backspace 
* M e s SPC return end C-x b return menu-bar help-menu 
report-emacs-bug

Recent messages:
Counting new messages...
Counting new messages...done (2)
Saving file /u/pascal/moniot/RMAIL...
Wrote /u/pascal/moniot/RMAIL
2 new messages read
No following nondeleted message
Auto-saving...
Autosaving...error for switching
No following nondeleted message
Mark set