[folks] Don't assume every Tpf.Persona has a contact

[Travis Reitter <treitter src gnome org>]

commit 50171f5392901dca6eb1af48cc76a7b0c7ad7b5b
Author: Travis Reitter <travis reitter collabora co uk>
Date:   Tue Jan 24 18:00:29 2012 -0800

    Don't assume every Tpf.Persona has a contact

 backends/telepathy/lib/tpf-persona-store.vala |   38 +++++++++++++++++++++++-
 1 files changed, 36 insertions(+), 2 deletions(-)
---
diff --git a/backends/telepathy/lib/tpf-persona-store.vala b/backends/telepathy/lib/tpf-persona-store.vala
index d5f76e9..b79577b 100644
--- a/backends/telepathy/lib/tpf-persona-store.vala
+++ b/backends/telepathy/lib/tpf-persona-store.vala
@@ -1234,7 +1234,10 @@ public class Tpf.PersonaStore : Folks.PersonaStore
                       /* Translators: the parameter is a persona identifier and
                        * the second parameter is a group name. */
                       warning (_("Failed to add Telepathy contact â%sâ to group â%sâ."),
-                          persona.contact.identifier, group);
+                          persona.contact != null ?
+                              persona.contact.identifier :
+                              "(nil)",
+                          group);
                     }
                   else
                     {
@@ -1242,7 +1245,11 @@ public class Tpf.PersonaStore : Folks.PersonaStore
                           /* Translators: the parameter is a persona identifier
                            * and the second parameter is a group name. */
                           _("Failed to remove Telepathy contact â%sâ from group â%sâ."),
-                          persona.contact.identifier, group);
+
+                          persona.contact != null ?
+                              persona.contact.identifier :
+                              "(nil)",
+                          group);
                     }
                 }
             }
@@ -1606,6 +1613,13 @@ public class Tpf.PersonaStore : Folks.PersonaStore
               _("Telepathy contacts representing the local user may not be removed."));
         }
 
+      if (tp_persona.contact == null)
+        {
+          warning ("Skipping server-side removal of Tpf.Persona %p because " +
+              "it has no attached TpContact", tp_persona);
+          return;
+        }
+
       try
         {
           FolksTpLowlevel.channel_group_change_membership (this._stored,
@@ -1798,6 +1812,13 @@ public class Tpf.PersonaStore : Folks.PersonaStore
     {
       var tp_persona = (Tpf.Persona) persona;
 
+      if (tp_persona.contact == null)
+        {
+          warning ("Skipping Tpf.Persona %p contact list change because it " +
+              "has no attached TpContact", tp_persona);
+          return;
+        }
+
       try
         {
           FolksTpLowlevel.channel_group_change_membership (channel,
@@ -2263,6 +2284,12 @@ public class Tpf.PersonaStore : Folks.PersonaStore
               _("Failed to change favorite without a connection to the telepathy-logger service."));
         }
 
+      if (((Tpf.Persona) persona).contact == null)
+        {
+          throw new PropertyError.INVALID_VALUE (
+              _("Failed to change favorite status of Telepathy Persona because it has no attached TpContact."));
+        }
+
       try
         {
           /* Add or remove the persona to the list of favourites as
@@ -2291,6 +2318,13 @@ public class Tpf.PersonaStore : Folks.PersonaStore
           alias = "";
         }
 
+      if (persona.contact == null)
+        {
+          warning ("Skipping Tpf.Persona %p alias change to '%s' because it " +
+              "has no attached TpContact", persona, alias);
+          return;
+        }
+
       debug ("Changing alias of persona %u to '%s'.", persona.contact.handle,
           alias);
       FolksTpLowlevel.connection_set_contact_alias (this._conn,