Bug#351698: apt-get should be able to ask download confirmation for source packages

[Victor Porton <porton@ex-code.com>]

Package: apt
Version: 0.5.24
Severity: wishlist

"apt-get source" should have a command line option to show the archive
(.tar.* file) size and ask confirmation for download (just like to how
"apt-get install" does).

I suggest to name this option --source-download-prompt

So we would have:

$ apt-get --source-download-prompt source qwerty
...
Need to get 4Mb of source archives, download? [Y/n] Y
...

Note: Ideally the number (4Mb in the example) should contain full size of
the source package (size of .tar.* file plus size of all patches and .dsc
file) but if it would include only size of .tar.* file, it would be not so
bad.

There should be also added corresponding option to apt.conf (like
APT::Get::Source::Download-Prompt).

The reason I ask for this feature is that on fast paid connections one may
quckly use all his money paid for Internet access with "apt-get source"
downloading big archives without any warning. So I strongly insist that
this feature is important. Another reason to implement it is that it will
reduce the load of Debian mirrors.