Update LICENSE.

Some of the license wording was less than clear. Try to clarify the
different GPL 'downgrade' scenarios but also be generic to ensure that
those packagers where GPL is a problem check thoroughly before they ship.

Inspired by comments from Brian Cameron @ Oracle via fdo#41822

1 files changed, 22 insertions, 9 deletions

diff --git a/LICENSE b/LICENSE
index 3a82749e..b312c44c 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,17 +1,30 @@
 All PulseAudio source files are licensed under the GNU Lesser General Public
 License. (see file LGPL for details)
 
-However, the server side links to the GPL-only library 'libsamplerate' which
-practically downgrades the license of the server part to GPL (see file GPL for
-details), exercising section 3 of the LGPL.
-
-Hence you should treat the client library ('libpulse') of PulseAudio as being
-LGPL licensed and the server part ('libpulsecore') as being GPL licensed. Since
-the PulseAudio daemon and the modules link to 'libpulsecore' they are of course
-also GPL licensed.
+However, the server side has optional GPL dependencies.  These include the
+libsamplerate (for core libraries) and bluez (for the bluetooth proximity helper
+program) libraries, although others may also be included in the future.  If
+PulseAudio is compiled with these optional components, this effectively
+downgrades the license of the server part to GPL (see file GPL for details),
+exercising section 3 of the LGPL. In such circumstances, you should treat the
+client library (libpulse) of PulseAudio as being LGPL licensed and the server
+part (libpulsecore) as being GPL licensed. Since the PulseAudio daemon, tests,
+various utilities/helpers and the modules link to libpulsecore and/or the
+afore mentioned optional GPL dependencies they are of course also GPL licensed
+also in this scenario.
 
 Andre Adrian's echo cancellation implementation is licensed under a less
 restrictive license - see src/modules/echo-cancel/adrian-license.txt for
 details.
 
--- Lennart Poettering, April 20th, 2006.
+Some other files pulled into PA source (i.e. reference implementations that are
+considered too small and stable to be considered as an external library) use the
+more permissive MIT license. This include the device reservation DBus protocol
+and realtime kit implementations.
+
+Additionally, a more permissive Sun license is used for code that performs
+u-law, A-law and linear PCM conversions.
+
+While we attempt to provide a summary here, it is the ultimate responsibility of
+the packager to ensure the components they use in their build of PulseAudio
+meets their license requirements.