#154 Add copyright header to each source file to pass Debian's licensecheck.pl script
It is a side effect of using requests in the Chromium project.
We have over 100 third party libraries in the codebase. While we audit all of their licenses, it's also helpful for Open Source Distributions like Debian and others to at least semi-automatically see what licenses apply to our 100+ libraries. For a team of volunteers this is a pretty big task, and having license headers in each file is helpful. Note that it doesn't need to be a full text of the license. For example in Chromium project we use this:
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
Still, it's preferred to use a full header if possible to help avoid any ambiguity. When people copy your library around, and bundle it as part of other third party project (the nesting can be 1 or even 2 levels deep), finding the right scope of a LICENSE file can be tricky, especially if it's missing (fortunately not the case here, but in general nothing is guaranteed). And then is it LICENSE, LICENSE.txt, COPYING, COPYING.txt and so on - it's trivial for people, but becomes increasingly non-trivial to automate.
This seems particularly important, since some files are licensed under the LGPL without restriction, and then the RAR files have the unRAR restriction. Making this clear in each file would be beneficial.
Also see the following for recommendations:
http://producingoss.com/en/license-quickstart.html
"The standard way to do this is to put the full license text in a file called COPYING (or LICENSE) included with the source code, and then put a short notice in a comment at the top of each source file, naming the copyright date, holder, and license, and saying where to find the full text of the license."