Bug#607088: [licensecheck] Public domain *.c and *.h not detected

[Dmitry Smirnov]

On Sun, 21 Oct 2012 09:33:33 Benjamin Drung wrote:
> 
> Isn't it possible to detect that the only license text is "Public
> domain", which matches one to one to "public domain"? We already report
> public domain licenses by matching "is in the public domain".

Than we'll have to detect or remove the noise, but I think such case is not 
worthy of automation. It is easy enough to read anyway...
Perhaps more difficult cases like reliable detection of modified licenses 
would be more important to address.

Also "Public domain" is not a license and there is no such thing in some 
jurisdictions. I think intention to disclaim copyright should be stated better 
than with two words "Public domain". It would be ridiculous if everything with 
"Public Domain" would be classified as non-copyrighted work so I think it's 
not accurate enough to detect "public-domain" work from just two words.

For example here is how they put some pieces of "john" to Public Domain:

 * This software was written by Jim Fougeron jfoug AT cox dot net
 * in 2009. No copyright is claimed, and the software is hereby
 * placed in the public domain. In case this attempt to disclaim
 * copyright and place the software in the public domain is deemed
 * null and void, then the software is Copyright . 2009 Jim Fougeron
 * and it is hereby released to the general public under the following
 * terms:
 *
 * This software may be modified, redistributed, and used for any
 * purpose, in source and binary forms, with or without modification.

or another (quite similar) example:

 * Written by Alain Espinosa <alainesp at gmail.com> in 2007 and
 * modified by magnum in 2011.  No copyright is claimed, and the
 * software is hereby placed in the public domain.
 * In case this attempt to disclaim copyright and place the software
 * in the public domain is deemed null and void, then the software is
 * Copyright (c) 2007 Alain Espinosa
 * Copyright (c) 2011 magnum
 * and it is hereby released to the general public under the following terms:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted.
 *
 * There's ABSOLUTELY NO WARRANTY, express or implied.

Regards,
Dmitry.