--- old/make/common/MakeBase.gmk	2015-02-11 09:14:30.910839057 +0100
+++ new/make/common/MakeBase.gmk	2015-02-11 09:14:30.802839055 +0100
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -444,6 +444,10 @@
 # Filter out duplicate sub strings while preserving order. Keeps the first occurance.
 uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
 
+# Return a list of all string elements that are duplicated in $1.
+dups = $(strip $(foreach v, $(sort $1), $(if $(filter-out 1, \
+    $(words $(filter $v, $1))), $v)))
+
 # String equals
 equals = \
     $(and $(findstring $(strip $1),$(strip $2)),\
@@ -548,7 +552,7 @@
 ################################################################################
 # ShellQuote
 #
-# Quotes a string with single quotes and replaces single quotes with '\'' so 
+# Quotes a string with single quotes and replaces single quotes with '\'' so
 # that the contents survives being given to the shell.
 
 ShellQuote = \
@@ -570,8 +574,8 @@
 ################################################################################
 # DependOnVariable
 #
-# This macro takes a variable name and puts the value in a file only if the 
-# value has changed since last. The name of the file is returned. This can be 
+# This macro takes a variable name and puts the value in a file only if the
+# value has changed since last. The name of the file is returned. This can be
 # used to create rule dependencies on make variable values. The following
 # example would get rebuilt if the value of SOME_VAR was changed:
 #