Issue 2440 - implement Source.get_cache_dir() to be used by custom filters/globals

cms/converters.py

Index: cms/converters.py
===================================================================
--- a/cms/converters.py
+++ b/cms/converters.py
@@ -308,16 +308,19 @@
       "get_page_content": self.get_page_content,
     }
 
+    source = self._params["source"]
     self._module_refs = []
     for dirname, dictionary in [("filters", filters), ("globals", globals)]:
-      for filename in self._params["source"].list_files(dirname):
+      for filename in source.list_files(dirname):
         root, ext = os.path.splitext(filename)
         if ext.lower() != ".py":
           continue
 
         path = "%s/%s" % (dirname, filename)
-        code = self._params["source"].read_file(path)
+        code = source.read_file(path)
         module = imp.new_module(root.replace("/", "."))
+        if hasattr(source, "get_cache_dir"):
+          module.CMS_CACHE_DIR = source.get_cache_dir()
         exec code in module.__dict__
 
         name = os.path.basename(root)