[PATCH setup v2] Query the user if a corrupt local file is found

[Ken Brown]

On 1/9/2018 5:25 PM, Ken Brown wrote:
> Also reorganize package validation.
> 
> Move the size-validation code in download.cc and the hash-validation
> code in install.cc into new member functions of the packagesource
> class.  Add a bool member 'validated' to the class to make sure that
> the checking is done only once.
> 
> Change download.cc:check_for_cached() so that it offers to delete a
> corrupt package file instead of throwing an exception.  The latter
> previously caused a fatal error when check_for_cached() was called
> from do_download_thread and download_one.  Now we get a fatal error
> only if the user chooses not to delete the file.
> 
> Also make check_for_cached() check the hash of the file in addition to
> the size.  Similarly, check the hash in addition to the size after
> downloading a file.

I missed 'pkgsource.set_cached ("")' in a couple places.  v3 is on the way.

Ken