Avoid early deletion/collection of gPodderWelcome (bug 1021)

The gPodderWelcome Python object was deleted and/or collected
after it fell out of scope, while the Gtk dialog was still
displayed. Work around this by running a separate main loop
for the dialog, so that the Python object stays alive longer.

This bug has been haunting us for quite some time now, and it
seems like the object hasn't always been collected, making it
harder to track down the bug. But rejoice, we finally fixed it!

src/gpodder/gtkui/interface/welcome.py

@@ -26,6 +26,9 @@
 from gpodder.gtkui.interface.common import BuilderWidget
 
 class gPodderWelcome(BuilderWidget):
+    RESPONSE_OPML = 1
+    RESPONSE_MYGPO = 2
+
     finger_friendly_widgets = ['btnOPML', 'btnMygPodder', 'btnCancel']
 
     def new(self):
@@ -40,16 +43,14 @@ def new(self):
             self.btnOPML.set_name('HildonButton-thumb')
             self.btnMygPodder.set_name('HildonButton-thumb')
 
-        self.gPodderWelcome.show()
+        self.main_window.show()
 
     def on_show_example_podcasts(self, button):
-        self.gPodderWelcome.destroy()
-        self.show_example_podcasts_callback(None)
+        self.main_window.response(self.RESPONSE_OPML)
 
     def on_setup_my_gpodder(self, gpodder):
-        self.gPodderWelcome.destroy()
-        self.setup_my_gpodder_callback(None)
+        self.main_window.response(self.RESPONSE_MYGPO)
 
     def on_btnCancel_clicked(self, button):
-        self.gPodderWelcome.destroy()
+        self.main_window.response(gtk.RESPONSE_CANCEL)
 

src/gpodder/gui.py

@@ -592,7 +592,7 @@ def on_resume_all(button):
 
         # First-time users should be asked if they want to see the OPML
         if not self.channels and not gpodder.ui.fremantle:
-            util.idle_add(self.on_itemUpdate_activate)
+            self.on_itemUpdate_activate()
 
     def episode_object_by_uri(self, uri):
         """Get an episode object given a local or remote URI
@@ -3346,11 +3346,19 @@ def on_itemUpdate_activate(self, widget=None):
         if self.channels:
             self.update_feed_cache()
         else:
-            gPodderWelcome(self.gPodder,
-                    center_on_widget=self.gPodder,
+            welcome_window = gPodderWelcome(self.main_window,
+                    center_on_widget=self.main_window,
                     show_example_podcasts_callback=self.on_itemImportChannels_activate,
                     setup_my_gpodder_callback=self.on_download_subscriptions_from_mygpo)
 
+            result = welcome_window.main_window.run()
+
+            welcome_window.main_window.destroy()
+            if result == gPodderWelcome.RESPONSE_OPML:
+                self.on_itemImportChannels_activate(None)
+            elif result == gPodderWelcome.RESPONSE_MYGPO:
+                self.on_download_subscriptions_from_mygpo(None)
+
     def download_episode_list_paused(self, episodes):
         self.download_episode_list(episodes, True)