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

scripts/xdg-icon-resource

Index: scripts/xdg-icon-resource
===================================================================
--- scripts/xdg-icon-resource	(revision 79914)
+++ scripts/xdg-icon-resource	(working copy)
@@ -400,9 +400,34 @@
     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
 }
 
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