[CLN-list] msvc support patch

[Bruno Haible]

Michael Goffioul wrote:
> This link will hopefully clarify this.
> 
> http://www.gnu.org/licenses/gpl-faq.html#WindowsRuntimeAndGPL

This FAQ does not make the distinction between whether the installer
contains the run-time libraries or not. Based on the verbiage in the GPL
(explained in the other mail) I therefore think that this FAQ assumes
that the installer does not contain the run-time libraries.

> there's no point in discussing the rest.

There is, because you or the Octave people have other ways to build
an installer that fulfils the letter of the GPL:

  - Build with an older version of MSVC++, whose runtime libraries
    are contained in the minimum version of Windows that your
    package supports, or

  - Distribute the the MSVC++ runtime libraries in a separate installer
    (then it's mere "aggregation" in the terms of the GPL), or

  - Arrange for the installer to pop up a browser window to the
    Microsoft VC++ redistributables download page.

The last two options are still not following the spirit of the GPL
(because they encourage the installation of closed-source libraries),
but legally not a GPL violation.

In the second option, there's also the Microsoft license that you have
to look at. I find it funny that the license in the "Microsoft
Visual C++ 2008 Redistributables" (vcredist_x86.exe) expressly
forbids redistributing its contents.

Bruno