[Bug-tar] tar with -k option no longer warns when not overwriting files

[Doug McLaren]

I just got surprised by a change in tar behavior ...

With a recent version (1.23, 1.26) of tar :

% touch foo 
% tar -cvf foo.tar foo
foo
% tar -kxvf foo.tar 
foo
% tar --warning=all  -kxvf foo.tar 
foo
% tar --warning=all --keep-old-files -xvvvf foo.tar
-rw-r--r-- dougmc/local      0 2011-11-16 22:43 foo

{ --warning=all is the default according to the docs, but I just made sure }

With an old version (1.20) of tar :

% touch foo
% tar -cvf foo.tar foo
% tar -cvf foo.tar foo
foo
% tar -kxvf foo.tar 
foo
tar: foo: Cannot open: File exists
tar: Error exit delayed from previous errors

Looking at the Changelog --

2009-05-14  Sergey Poznyakoff  <address@hidden>
        Do not issue errors on existing files when given the -k option

... so this is intentional, and it makes sense -- an error probably
isn't appropriate.  But no message at all?

I would propose that if a file is not put down due to it already
existing and the -k / --keep-old-files flag being given, that a
warning should be thrown.  (Really, it's more of an informational
message, but the logging mechanism isn't that fancy.)

-- 
Doug McLaren, address@hidden