Wordpress source files do not correctly mark themselves as GPL

Why isn't the license.txt file sufficient?

The license states that this is the correct way to mark your files. It also helps people who want to use functions from the source code in their own programs understand the license :)

I checked with the licensing people at the FSF :)

Replying to mattlgnu:

The license states that this is the correct way to mark your files.

Sorry to be obtuse, but could you quote the relevant section?

http://www.gnu.org/licenses/old-licenses/gpl-2.0.html#SEC4

f you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found.

one line to give the program's name and an idea of what it does. Copyright (C) yyyy name of author

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

That's not part of the license; it's a recommendation on the part of the GNU folks, "to most effectively convey the exclusion of warranty."

My questions are whether the license requires that these lines appear at the beginning of each included file (this does not seem to be the case), and whether the license is somehow invalidated if not done this way or whether there is good legal reason to do so (I have my doubts).

Without good reasons to do so, including an extra 160kb of text--about a 4% increase in 2.5's overall size--just seems like a waste of space to me.

I think the main point is that by not having this, it makes the source files very clearly licensed under the GNU GPL. It is not beyond the realms of possibility for someone to either include one of the Wordpress php files in their project, or to find one by itself and use it in their project.

By having all the files marked with the correct headers, you explictly declare it to a) be a part of Wordpress and b) Under the GNU GPL.

Having the license explicit like this would also make sense, if there were ever any legal question over someone using Wordpress sources in their non-GPL project, as they would have to remove the headers.

1. You need to have PHP comments with the <?php ... ?> tags.
2. Some of the files you are documenting as "Part of WordPress..." are actually external libraries separate from WordPress and Automattic does not hold the copyright to.
3. Automattic does not hold the copyright to the code or at least not to my code. If Automattic wants the copyright to my code, I only offered my code as GPL. It would be better to just say "@copyright WordPress". Automattic can't own the copyright to WordPress, because so many other people also hold copyrights to their code. In order for Automattic to gain that copyright, they would have to contact the original B2 author and contributors, as well as the past and current WordPress contributors. If Automattic owned the copyright, they could easily say that WordPress is now under a commercial license tomorrow and we'll all be screwed, but luckily Automattic isn't that evil (...yet).
4. You should look into phpdoc for file level comments, some files already have file level phpdoc. If you add the @license GPL 2.0 <link>, which is a single line directing to the GPL file, then that would be okay.

You have to fix the first problem first, because committing your patch as it is now would violate the copyrights of the external files and would break (or at least show the comments that WordPress is GPL, which is plain useless to the visitors).

Replying to darkdragon:

Not to mention add 160Kb to the total code size. Let's not lose sight of the not-inconsiderable costs this GPL-championing would incur.

I believe I've went over this before. Comments add only a few milliseconds overhead and only barely that. The PHP Engine does a very good job removing PHP comments from the source, with opcode caching you'll never notice that there were comments in the first place.

Comment themselves should not be considered overhead, because of the advantages of having comments far outweigh the extremely small amount of overhead in the parse stage of PHP.

I'm going to resolve this as invalid. Not even the Linux source marks each file explicitly as GPL licensed. I'm not a legal expert but I think that the license.txt is sufficient as the absence of a license when looking at a source file in isolation doesn't give you any distribution rights.

What may need to be fixed is something like the Akismet plugin which is distributed as a package in it's own right but doesn't include any license details in the source. This isn't the Akismet trac though :-)