Linux: update xdg-utils again, and check in the built versions of the scripts.

scripts/xdg-desktop-menu

 #!/bin/sh
 #---------------------------------------------
 #   xdg-desktop-menu
 #
 #   Utility script to install menu items on a Linux desktop.
 #   Refer to the usage() function below for usage.
 #
 #   Copyright 2009-2010, Fathi Boudra <fabo@freedesktop.org>
 #   Copyright 2009-2010, Rex Dieter <rdieter@fedoraproject.org>
 #   Copyright 2006, Kevin Krammer <kevin.krammer@gmx.at>
@@ skipping 64 matching lines @@
     or more category keywords, or they can be added to a new submenu.
 
     To add a menu entry to a predefined submenu the desktop file that
     represents the menu entry must have a Categories= entry that lists one or
     more keywords. The menu item will be included in an appropriate submenu
     based on the included keywords.
 
     To add menu items to a new submenu the desktop-files must be preceded by a
     directory-file that describes the submenu. If multiple desktop-files are
     specified, all entries will be added to the same menu. If entries are
-    installed to a menu that has been created with a previous call to 
+    installed to a menu that has been created with a previous call to
     xdg-desktop-menu the entries will be installed in addition to any already
     existing entries.
 
     directory-file: The *.directory file indicated by directory-file represents
     a submenu. The directory file provides the name and icon for a submenu. The
     name of the directory file is used to identify the submenu.
 
     If multiple directory files are provided each file will represent a submenu
     within the menu that preceeds it, creating a nested menu hierarchy
     (sub-sub-menus). The menu entries themselves will be added to the last
@@ skipping 501 matching lines @@
 #--------------------------------------
 # Checks for known desktop environments
 # set variable DE to the desktop environments name, lowercase
 
 detectDE()
 {
     if [ x"$KDE_FULL_SESSION" = x"true" ]; then DE=kde;
     elif [ x"$GNOME_DESKTOP_SESSION_ID" != x"" ]; then DE=gnome;
     elif `dbus-send --print-reply --dest=org.freedesktop.DBus /org/freedesktop/DBus org.freedesktop.DBus.GetNameOwner string:org.gnome.SessionManager > /dev/null 2>&1` ; then DE=gnome;
     elif xprop -root _DT_SAVE_MODE 2> /dev/null | grep ' = \"xfce4\"$' >/dev/null 2>&1; then DE=xfce;
-    elif [ x"$DESKTOP_SESSION" == x"LXDE" ]; then DE=lxde;
-    else DE=""
+    fi
+
+    if [ x"$DE" = x"" ]; then
+      # fallback to checking $DESKTOP_SESSION
+      case "$DESKTOP_SESSION" in
+         LXDE)
+           DE=lxde; 
+           ;;
+         xfce|xfce4)
+           DE=xfce;
+           ;;
+      esac
+    fi
+
+    if [ x"$DE" = x"" ]; then
+      # fallback to uname output for other platforms
+      case "$(uname 2>/dev/null)" in 
+        Darwin)
+          DE=darwin;
+          ;;
+      esac
+    fi
+
+    if [ x"$DE" = x"gnome" ]; then
+      # gnome-default-applications-properties is only available in GNOME 2.x
+      # but not in GNOME 3.x
+      which gnome-default-applications-properties 2> /dev/null || DE="gnome3"
     fi
 }
 
 #----------------------------------------------------------------------------
 # kfmclient exec/openURL can give bogus exit value in KDE <= 3.5.4
 # It also always returns 1 in KDE 3.4 and earlier
 # Simply return 0 in such case
 
 kfmclient_fix_exit_code()
 {
@@ skipping 61 matching lines @@
                 DEBUG 2 "Found default apps for $MIME: $default_app"
                 default_app="$default_app;"
                 break;
             fi
         done
         DEBUG 2 "Current default apps for $MIME: $default_app"
         if echo "$default_app" | grep "$2" > /dev/null 2> /dev/null; then
             # App already listed as default
             continue;
         fi
-        default_file="$1/defaults.list"
+        default_file="$(readlink -f "$1/defaults.list")"
         DEBUG 1 "Updating $default_file"
         grep -v "$MIME=" $default_file > ${default_file}.new 2> /dev/null
         if ! grep "[Default Applications]" ${default_file}.new > /dev/null; then
             echo "[Default Applications]" >> ${default_file}.new
         fi
         echo $MIME="$default_app$2" >> ${default_file}.new
         mv ${default_file}.new $default_file
     done
 }
 
@@ skipping 517 matching lines @@
 
             ;;
     esac
 done
 
 if [ x"$update" = x"yes" ] ; then
     update_desktop_database
 fi
 
 exit_success