[Bug-tar] tar -d not working correctly in conjunction with tar -u

[Leonard den Ottolander]

Hello,

When using tar -df on an updated tarball updated with tar -uf tar diffs
against the original files instead of the updated ones. This causes tar
to erroneously report that there are differences between the actual tree
and the updated archive.

$ mkdir -p tmp/foo
$ cd tmp
$ touch foo/bar
$ tar -cf foo.tar foo/
$ tar -df foo.tar foo/
$ mcedit foo/bar
$ tar -df foo.tar foo/
foo/bar: Mod time differs
foo/bar: Size differs
$ tar -uf foo.tar foo/
$ tar -df foo.tar foo/
foo/bar: Mod time differs
foo/bar: Size differs

As the tarball has just been updated the last invocation of tar -d
should report no differences.

First noticed the issue with tar-1.23 on CentOS-6, but it also exists
with tar-1.26 on Fedora 17.

Regards,
Leonard den Ottolander.

-- 
mount -t life -o ro /dev/dna /genetic/research