Issue 2434 - Fixed: Custom filters and global functions can not be instance methods

cms/converters.py

Index: cms/converters.py
===================================================================
--- a/cms/converters.py
+++ b/cms/converters.py
@@ -308,6 +308,7 @@
       "get_page_content": self.get_page_content,
     }
 
+    self._module_refs = []
     for dirname, dictionary in [("filters", filters), ("globals", globals)]:
       for filename in self._params["source"].list_files(dirname):
         root, ext = os.path.splitext(filename)
@@ -327,11 +328,8 @@
         # HACK: The module we created here can be garbage collected because it
         # isn't added to sys.modules. If a function is called and its module is
         # gone it might cause weird errors (imports and module variables
-        # unavailable). We avoid this situation by explicitly referencing the
-        # module from the function so they can only be garbage collected
-        # together.
-        if callable(dictionary[name]):
-          dictionary[name].module_ref = module
+        # unavailable). We avoid this situation by keeping a reference.
+        self._module_refs.append(module)
 
     self._env = jinja2.Environment(loader=self._SourceLoader(self._params["source"]), autoescape=True)
     self._env.filters.update(filters)