[mutter] build: Fetch pipewire micro version

[Florian Müllner <fmuellner src gnome org>]

commit 18c41aefc982864225ea993a0d0213e22e07e62e
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Oct 5 21:38:25 2017 +0200

    build: Fetch pipewire micro version
    
    Pipewire doesn't export its version defines, so the API checks added
    in commit f0c6c4eb1fa2b21e38 effectively disable screencasting, whoops.
    Breaking changes like this should disappear once the library stabilizes,
    so simply define the version ourselves instead of writing a "proper"
    test with AC_COMPILE_IFELSE() ...
    
    https://bugzilla.gnome.org/show_bug.cgi?id=788572

 configure.ac |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 89c15e2..a5870e6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -245,6 +245,10 @@ AC_ARG_ENABLE(remote-desktop,
 )
 AS_IF([test "$enable_remote_desktop" = "yes"], [
   MUTTER_PC_MODULES="$MUTTER_PC_MODULES libpipewire-0.1 >= 0.1.4"
+  PKG_CHECK_EXISTS([libpipewire-0.1], [
+    pw_micro=`$PKG_CONFIG --modversion libpipewire-0.1 | cut -d. -f3`
+    AC_DEFINE_UNQUOTED([PIPEWIRE_VERSION_MICRO],[$pw_micro], [Pipewire micro version used])
+  ])
   AC_DEFINE([HAVE_REMOTE_DESKTOP],[1], [Defined if screen cast and remote desktop support is enabled])
 ])
 AM_CONDITIONAL([HAVE_REMOTE_DESKTOP],[test "$enable_remote_desktop" = "yes"])