From: matz@... (Yukihiro Matsumoto)
Date: 2003-05-11T03:13:13+09:00
Subject: Re: PStore and tempfiles - bug?

Hi,

In message "Re: PStore and tempfiles - bug?"
    on 03/05/08, Paul Brannan <pbrannan@atdesk.com> writes:

|I don't need a backup.  It should be possible to turn this off.

Why?  You don't make mistake?  I always do.

|> q2: Why isn't it removed when the program is complete?
|> a2: You can't remove a backup file.  If you do, it's no longer a backup. ;-)
|
|There is code in pstore.rb to remove the backup file:
|
|        if @abort and !orig
|          File.unlink(@filename)
|        end
|
|But orig is never false, so the backup never gets removed.  I don't know
|what the author's intention was, but I'm sure unreachable code was not
|it.

It's for the case:

  * there's not foo, but foo~.
  * transaction is aborted.

This is very rare case, but not impossible.  I wanted to remove
unrelated files which look like backup files.

|> q3: are there any potential problems associated with the tempfile or
|>     can I safely ignore this issue?
|> a3: You can ignore it, until you need backup.
|
|I agree, but note that the backup file disappears if writing to the file
|fails.  You cannot depend on its existence.

Hmm, I assume the author (me) wanted back files to exist when

  * the pstore file had existed before the transaction
  * and pstore file had changed by the transaction

So I thought it's natural to restore original file by renaming it from
the backup.  If there's no backup files, we can assume no modification
has done by the last transaction.  Am I wrong somewhere?

							matz.