--- old/test/make/TestMakeBase.gmk	2016-04-12 15:41:41.157583801 +0200
+++ new/test/make/TestMakeBase.gmk	2016-04-12 15:41:41.077580418 +0200
@@ -254,4 +254,14 @@
       but was $(call sequence, 5, 15))
 endif
 
+################################################################################
+# Test that PathList is safe when called multiple times.
+
+PATHLIST_INPUT := foo bar baz
+
+$(eval $(call assert-equals, \
+    $(call PathList, $(call PathList, $(PATHLIST_INPUT))), \
+    $(call PathList, $(PATHLIST_INPUT)), \
+    PathList call not safe for calling twice))
+
 all: $(TEST_TARGETS)