Python: Add type-tracking regession example

Author: RasmusWL

python/ql/test/experimental/dataflow/typetracking/test.py

@@ -158,3 +158,27 @@ def test_long_import_chain_full_path():
     from foo.bar import baz # $ tracked_foo_bar_baz
     x = baz # $ tracked_foo_bar_baz
     do_stuff(x) # $ tracked_foo_bar_baz
+
+# ------------------------------------------------------------------------------
+# Global variable to method body flow
+# ------------------------------------------------------------------------------
+
+some_value = get_tracked() # $ tracked
+other_value = get_tracked() # $ tracked
+print(some_value) # $ tracked
+print(other_value) # $ tracked
+
+class MyClass(object):
+    # Since we define some_value method on the class, flow for some_value gets blocked
+    # into the methods
+    def some_value(self):
+        print(some_value) # $ MISSING: tracked
+        print(other_value) # $ tracked
+
+    def other_name(self):
+        print(some_value) # $ MISSING: tracked
+        print(other_value) # $ tracked
+
+    def with_global_modifier(self):
+        global some_value
+        print(some_value) # $ tracked