savannah: MC fail to notice when archive is replaced

[slavazanko]

Original: http://savannah.gnu.org/bugs/?19328

Submitted by:	Martin Petricek <bilboq>	Submitted on:	Fri 16 Mar 2007 10:45:16 PM UTC
Category:	VFS	Severity:	3 - Normal
Status:	None	Privacy:	Public
Assigned to:	None	Open/Closed:	Open
Release:	current (CVS or snapshot)	Operating System:	GNU/Linux

Discussion:

Fri 18 May 2007 01:51:04 PM UTC, comment #1:

Some VFS (for example tar and cpio) can detect changed archives,
others (bzip, extfs) can't. There is no consistent support of change
detection in VFS.
	Vladimir Nadvornik <nadvornik>
Fri 16 Mar 2007 10:45:16 PM UTC, original submission:

When .tar.bz2 archive is replaced, VFS in MC fails to notice it.
If you pack some files, examine the archive, then repack the archive
with different files, you see still old files.

How to reproduce:

Create two valid archives with distinct content (does not matter 
what content, just it have to be distinct files):
a.tar.bz2 and b.tar.bz2

Now move cursor to a.tar.bz2 and press enter. You see the contents. 
Fine, now go back, delete a.tar.bz2 and rename b.tar.bz2 to 
a.tar.bz2. Move to a.tar.bz2 (which is actually a renamed b.tar.bz2)
and press enter. You will see cached content of previous a.tar.bz2 
and you can even extract the files, even though the archive is 
deleted (I suppose a copy lives in /tmp or in memory)

Suggested fix: check date and size of archive when entering it. If 
it does not match, re-read the archive. This should fix most of the 
cases.
Clean, but maybe slower solution is to re-read archive every time it
is entered.

I suppose this bug may also affect other archive types (.tar.gz?), 
though I have not tested it.
	Martin Petricek <bilboq>

[metux]

Also affects packagers like dpkg.

[zyv]

Also affects PATCHFS :(

[zyv]

See duplicate #349 for an idea on how to solve this problem.