diff --git a/src/klayout.pri b/src/klayout.pri
index 07c8a0c41..298273ebc 100644
--- a/src/klayout.pri
+++ b/src/klayout.pri
@@ -113,7 +113,7 @@ msvc {
 
   CONFIG(gcov) {
     QMAKE_CXXFLAGS += -fprofile-arcs -ftest-coverage
-    QMAKE_LFLAGS += -fprofile-arcs -ftest-coverage
+    QMAKE_LFLAGS += --coverage
   }
 
   QMAKE_CXXFLAGS_WARN_ON += \
diff --git a/src/plugins/tools/netx/testdata/hlp5.oas b/src/plugins/tools/netx/testdata/hlp5.oas
new file mode 100644
index 000000000..709b3a865
Binary files /dev/null and b/src/plugins/tools/netx/testdata/hlp5.oas differ
diff --git a/src/plugins/tools/netx/testdata/hlp6.oas b/src/plugins/tools/netx/testdata/hlp6.oas
new file mode 100644
index 000000000..a21da1c9c
Binary files /dev/null and b/src/plugins/tools/netx/testdata/hlp6.oas differ
diff --git a/src/plugins/tools/netx/testdata/hlp7.oas b/src/plugins/tools/netx/testdata/hlp7.oas
new file mode 100644
index 000000000..a167833a8
Binary files /dev/null and b/src/plugins/tools/netx/testdata/hlp7.oas differ
diff --git a/src/plugins/tools/netx/unit_tests/dbHierProcessorTests.cc b/src/plugins/tools/netx/unit_tests/dbHierProcessorTests.cc
index d7bd48367..5d82fc840 100644
--- a/src/plugins/tools/netx/unit_tests/dbHierProcessorTests.cc
+++ b/src/plugins/tools/netx/unit_tests/dbHierProcessorTests.cc
@@ -160,3 +160,27 @@ TEST(BasicNot5)
   //  Variant building with intermediate hierarchy, NOT
   run_test_bool (_this, "hlp5.oas", TMNot, 101);
 }
+
+TEST(BasicAnd6)
+{
+  //  Extreme variants (copy, vanishing), AND
+  run_test_bool (_this, "hlp6.oas", TMAnd, 100);
+}
+
+TEST(BasicNot6)
+{
+  //  Extreme variants (copy, vanishing), NOT
+  run_test_bool (_this, "hlp6.oas", TMNot, 101);
+}
+
+TEST(BasicAnd7)
+{
+  //  Context replication - direct and indirect, AND
+  run_test_bool (_this, "hlp7.oas", TMAnd, 100);
+}
+
+TEST(BasicNot7)
+{
+  //  Context replication - direct and indirect, NOT
+  run_test_bool (_this, "hlp7.oas", TMNot, 101);
+}