check for polkit_authority_get_sync

polkit_authority_get_sync does not exist in policykit 0.96 which is still
widely used. Use the depricated function polkit_authority_get on older
versions.

CMakeLists.txt

@@ -34,6 +34,10 @@ endif(ENABLE_DBUS)
 
 pkg_check_modules(GIO gio-2.0 REQUIRED)
 
+if(POLKIT_FOUND)
+  INCLUDE (CheckLibraryExists)
+  CHECK_LIBRARY_EXISTS(polkit-gobject-1 polkit_authority_get_sync "" POLKIT_HAVE_GET_SYNC)
+endif(POLKIT_FOUND)
 
 # FIXME: libproc should export more symbols
 # find libproc

src/config.h.tmpl

@@ -29,6 +29,7 @@
 #cmakedefine ENABLE_DBUS
 #cmakedefine DEVELOP_DBUS_SESSION
 #cmakedefine POLKIT_FOUND
+#cmakedefine POLKIT_HAVE_GET_SYNC
 #cmakedefine DEVELOP_MODE
 #ifdef DEVELOP_MODE
 #define RELEASE_AGENT ${CMAKE_CURRENT_BINARY_DIR}/src/ulatencyd_cleanup.lua

src/core.c

@@ -1809,7 +1809,11 @@ int core_init() {
 #endif
 
 #ifdef POLKIT_FOUND
+#ifdef POLKIT_HAVE_GET_SYNC
   U_polkit_authority = polkit_authority_get_sync (NULL, NULL);
+#else
+  U_polkit_authority = polkit_authority_get();
+#endif
 #endif
   // delay stack 
   delay_stack = g_ptr_array_new_with_free_func(free);