[folks] core: Fix FOLKS_DISABLE_LINKING

[Philip Withnall <pwithnall src gnome org>]

commit 1b770fb19a9c1b8e5f9ce0e3ab00d75fd3af5ca1
Author: Renato Araujo Oliveira Filho <renato filho canonical com>
Date:   Mon Mar 31 16:14:16 2014 -0300

    core: Fix FOLKS_DISABLE_LINKING
    
    The second step of the _add_personas() function looks at candidate_inds,
    which is currently populated even if linking is disabled (in a failed
    attempt to keep all the FOLKS_DISABLE_LINKING logic to a single
    if-statement at the bottom of the function).
    
    This patch takes a different approach, and ensures that candidate_inds
    is not populated if FOLKS_DISABLE_LINKING is enabled, adding an
    assertion to try and prevent this bug being re-introduced in future.
    
    A test case will be added in a future commit (see the bug report).
    
    https://bugzilla.gnome.org/show_bug.cgi?id=727405

 NEWS                             |    3 ++-
 folks/individual-aggregator.vala |   18 ++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)
---
diff --git a/NEWS b/NEWS
index 60fbc54..6380bd6 100644
--- a/NEWS
+++ b/NEWS
@@ -11,13 +11,14 @@ Bugs fixed:
  • Bug 648811 — Add a dummy backend
  • Bug 720707 — New strings partly not translatable
  • Bug 722335 — non-void function should return a value
- • Bug 723054 - edsf-persona.vala:1666.21-1666.79: error: Reference transfer
+ • Bug 723054 — edsf-persona.vala:1666.21-1666.79: error: Reference transfer
    not supported for this expression
  • Bug 723540 — standalone-individuals test failing with master
  • Bug 724339 — vala.m4: don't keep generated files in git
  • Bug 724809 — Fail to unset contact favorite
  • Bug 722892 — Linking personas on Dummy backend does not work
  • Bug 726980 — dependency on e-d-s 3.9 is often unnecessary
+ • Bug 727405 — setting FOLKS_DISABLE_LINKING to on does not work
 
 API changes:
  • Add Individual.display_name
diff --git a/folks/individual-aggregator.vala b/folks/individual-aggregator.vala
index 06d0f3d..e1da1da 100644
--- a/folks/individual-aggregator.vala
+++ b/folks/individual-aggregator.vala
@@ -1213,7 +1213,8 @@ public class Folks.IndividualAggregator : Object
 
           /* If the Persona is the user, we *always* want to link it to the
            * existing this.user. */
-          if (persona.is_user == true && user != null &&
+          if (this._linking_enabled == true &&
+              persona.is_user == true && user != null &&
               ((!) user).has_anti_link_with_persona (persona) == false)
             {
               debug ("    Found candidate individual '%s' as user.",
@@ -1223,7 +1224,8 @@ public class Folks.IndividualAggregator : Object
 
           /* If we don't trust the PersonaStore at all, we can't link the
            * Persona to any existing Individual */
-          if (trust_level != PersonaStoreTrust.NONE)
+          if (this._linking_enabled == true &&
+              trust_level != PersonaStoreTrust.NONE)
             {
               unowned GenericArray<Individual>? candidates =
                   this._link_map.get (persona.iid);
@@ -1245,7 +1247,8 @@ public class Folks.IndividualAggregator : Object
                 }
             }
 
-          if (persona.store.trust_level == PersonaStoreTrust.FULL)
+          if (this._linking_enabled == true &&
+              persona.store.trust_level == PersonaStoreTrust.FULL)
             {
               /* If we trust the PersonaStore the Persona came from, we can
                * attempt to link based on its linkable properties. */
@@ -1304,6 +1307,7 @@ public class Folks.IndividualAggregator : Object
           /* Ensure the original persona makes it into the final individual */
           final_personas.add (persona);
 
+          assert (this._linking_enabled == true || candidate_inds.size == 0);
           if (candidate_inds.size > 0 && this._linking_enabled == true)
             {
               /* The Persona's IID or linkable properties match one or more
@@ -1316,7 +1320,7 @@ public class Folks.IndividualAggregator : Object
                   final_personas.add_all (individual.personas);
                 }
             }
-          else if (candidate_inds.size > 0)
+          else if (!this._linking_enabled)
             {
               debug ("    Linking disabled.");
             }
@@ -1400,6 +1404,12 @@ public class Folks.IndividualAggregator : Object
   private void _persona_linkable_property_changed_cb (Object obj,
       ParamSpec pspec)
     {
+      /* Ignore it if the link is disabled */
+      if (this._linking_enabled == false)
+        {
+          return;
+        }
+
       /* The value of one of the linkable properties of one the personas has
        * changed, so that persona might require re-linking. We do this in a
        * simplistic and hacky way (which should work) by simply treating the