Fixed t00039 relationship filter case

docs/test_cases/t00039.md

@@ -0,0 +1,50 @@
+# t00039 - Subclass class diagram filter test
+## Config
+```yaml
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t00039_class:
+    type: class
+    generate_packages: false
+    glob:
+      - ../../tests/t00039/t00039.cc
+    using_namespace:
+      - clanguml::t00039
+    include:
+      subclasses:
+        - clanguml::t00039::A
+      relationships:
+        - extension
+```
+## Source code
+File t00039.cc
+```cpp
+namespace clanguml::t00039 {
+struct B {
+};
+
+namespace ns1 {
+struct BB : public B {
+};
+} // namespace ns1
+
+struct A {
+};
+
+struct AA : public A {
+};
+
+struct AAA : public AA {
+    B *b;
+};
+
+namespace ns2 {
+struct AAAA : public AAA {
+};
+} // namespace ns2
+} // namespace clanguml::t00039
+
+```
+## Generated UML diagrams
+![t00039_class](./t00039_class.svg "Subclass class diagram filter test")