Fix garbage collection issue in ConfigManager

Instances of the python configparser are not removed by the
garbage collector unless some internal objects are deleted first.
This is not an issue on the first run where we load the main
Gramps ini file, but on subsequent runs there are uncollected
objects after loading the view configuration files.

This fix is not ideal because it accesses protected attributes
of the configparser.

gramps/gen/utils/configmanager.py

@@ -47,6 +47,14 @@ from ..const import GRAMPS_LOCALE as glocale
 
 _ = glocale.translation.gettext
 
+def clean_up(parser):
+    # Needed so that the parser can be removed by the garabge collection
+    for section in parser:
+        delattr(parser._proxies[section], 'getboolean')
+        delattr(parser._proxies[section], 'getint')
+        delattr(parser._proxies[section], 'getfloat')
+        del parser._proxies[section]
+    del parser._converters
 
 def safe_eval(exp):
     # restrict eval to empty environment
@@ -287,6 +295,8 @@ class ConfigManager:
                     self.data[name] = {}
                 loader(section, parser)
 
+            clean_up(parser)
+
     def _load_section(self, section, parser):
         """
         Load a section of an .ini file into self.data

gramps/gui/widgets/grampletbar.py

@@ -58,6 +58,7 @@ _ = glocale.translation.gettext
 from gramps.gen.const import URL_MANUAL_PAGE, URL_WIKISTRING, VERSION_DIR
 from gramps.gen.config import config
 from gramps.gen.constfunc import win
+from gramps.gen.utils.configmanager import clean_up
 from ..managedwindow import ManagedWindow
 from ..display import display_help, display_url
 from .grampletpane import (AVAILABLE_GRAMPLETS,
@@ -210,6 +211,7 @@ class GrampletBar(Gtk.Notebook):
                         data["name"] = "Unnamed Gramplet"
                         data["tname"] = _("Unnamed Gramplet")
                     retval.append(data)
+            clean_up(cp)
         else:
             # give defaults as currently known
             for name in defaults:

gramps/gui/widgets/grampletpane.py

@@ -47,6 +47,7 @@ LOG = logging.getLogger(".")
 #-------------------------------------------------------------------------
 from gramps.gen.errors import WindowActiveError
 from gramps.gen.const import URL_MANUAL_PAGE, VERSION_DIR, COLON
+from gramps.gen.utils.configmanager import clean_up
 from ..editors import EditPerson, EditFamily
 from ..managedwindow import ManagedWindow
 from ..utils import is_right_click, match_primary_mask, get_link_color
@@ -1194,6 +1195,7 @@ class GrampletPane(Gtk.ScrolledWindow):
                         data["name"] = "Unnamed Gramplet"
                         data["tname"] = _("Unnamed Gramplet")
                     retval.append((data["name"], data)) # name, opts
+            clean_up(cp)
         else:
             # give defaults as currently known
             for name in self.default_gramplets: