Python: Add funky call-graph regression

I don't even know how to phrase this :D

Author: RasmusWL

python/ql/test/experimental/library-tests/CallGraph/InlineCallGraphTest.expected

@@ -17,6 +17,7 @@ pointsTo_found_typeTracker_notFound
 | code/func_defined_outside_class.py:39:11:39:21 | ControlFlowNode for _gen() | B._gen |
 | code/func_defined_outside_class.py:42:1:42:7 | ControlFlowNode for Attribute() | B._gen.func |
 | code/func_defined_outside_class.py:43:1:43:7 | ControlFlowNode for Attribute() | B._gen.func |
+| code/funky_regression.py:15:9:15:17 | ControlFlowNode for Attribute() | Wat.f2 |
 | code/type_tracking_limitation.py:8:1:8:3 | ControlFlowNode for x() | my_func |
 typeTracker_found_pointsTo_notFound
 | code/callable_as_argument.py:29:5:29:12 | ControlFlowNode for Attribute() | test_class.InsideTestFunc.sm |

python/ql/test/experimental/library-tests/CallGraph/code/funky_regression.py

@@ -0,0 +1,63 @@
+# When this regression was discovered, we did not resolve the `self.f2()` call after the
+# try-except block, but ONLY when passing an attribute to a method, as indicated in the
+# other tests below.
+
+class Wat(object):
+    def f1(self, arg): pass
+    def f2(self): pass
+
+    def func(self, foo):
+        try:
+            self.f1(foo.bar) # $ pt,tt=Wat.f1
+        except Exception as e:
+            raise e
+
+        self.f2() # $ pt=Wat.f2 MISSING: tt=Wat.f2
+
+
+# ==============================================================================
+# variants that we are able to handle
+# ==============================================================================
+
+
+class Works(object):
+    "not using attribute"
+    def f1(self, arg): pass
+    def f2(self): pass
+
+    def func(self, foo):
+        try:
+            self.f1(foo) # $ pt,tt=Works.f1
+        except Exception as e:
+            raise e
+
+        self.f2() # $ pt,tt=Works.f2
+
+
+class AlsoWorks(object):
+    "no exception"
+    def f1(self, arg): pass
+    def f2(self): pass
+
+    def func(self, foo):
+        self.f1(foo.bar) # $ pt,tt=AlsoWorks.f1
+
+        self.f2() # $ pt,tt=AlsoWorks.f2
+
+
+def safe_func(arg):
+    pass
+
+
+class Works3(object):
+    "call to non-self function"
+    def f1(self, arg): pass
+    def f2(self): pass
+
+    def func(self, foo):
+        try:
+            safe_func(foo.bar) # $ pt,tt=safe_func
+        except Exception as e:
+            raise e
+
+        self.f2() # $ pt,tt=Works3.f2