[telepathy-mission-control/master] McdAccount: remove incorrect "optimization" using an array of property GValues

[Simon McVittie]

Previously, this code would copy changed properties into a GArray of
GValue, populate a GHashTable with pointers into the GArray's memory
buffer, and emit that GHashTable in the delayed PropertiesChanged signal.

This was fine until the GArray ran out of space in its memory buffer
and triggered a realloc(), at which point the GValues would be copied
to the new buffer, leaving the values in the GHashTable pointing to the
old (cleared and/or freed) memory buffer. At this point, emitting the
signal would cause a crash. The regression test
account-manager/make-valid.py causes this failure mode.

In practice, slice-allocating the GValues individually is likely to be
just as efficient, so do that instead.
---
 src/mcd-account.c |   21 ++++-----------------
 1 files changed, 4 insertions(+), 17 deletions(-)

diff --git a/src/mcd-account.c b/src/mcd-account.c
index 8726c59..f7a6117 100644
--- a/src/mcd-account.c
+++ b/src/mcd-account.c
@@ -144,7 +144,6 @@ struct _McdAccountPrivate
 
     /* These fields are used to cache the changed properties */
     GHashTable *changed_properties;
-    GArray *property_values;
     guint properties_source;
 };
 
@@ -712,9 +711,6 @@ emit_property_changed (gpointer userdata)
 
     g_hash_table_remove_all (priv->changed_properties);
 
-    g_array_free (priv->property_values, TRUE);
-    priv->property_values = NULL;
-
     priv->properties_source = 0;
     return FALSE;
 }
@@ -732,7 +728,6 @@ mcd_account_changed_property (McdAccount *account, const gchar *key,
 {
 #ifdef DELAY_PROPERTY_CHANGED
     McdAccountPrivate *priv = account->priv;
-    GValue *val;
 
     DEBUG ("called: %s", key);
     if (priv->changed_properties &&
@@ -750,24 +745,18 @@ mcd_account_changed_property (McdAccount *account, const gchar *key,
     {
 	priv->changed_properties =
 	    g_hash_table_new_full (g_str_hash, g_str_equal,
-				   NULL, (GDestroyNotify)g_value_unset);
+				   NULL,
+                                   (GDestroyNotify) tp_g_value_slice_free);
     }
 
     if (priv->properties_source == 0)
     {
         DEBUG ("First changed property");
-	priv->property_values = g_array_sized_new (FALSE, FALSE,
-						   sizeof (GValue), 4);
 	priv->properties_source = g_timeout_add (10, emit_property_changed,
 						 account);
     }
-    g_array_append_vals (priv->property_values, value, 1);
-    val = &g_array_index (priv->property_values, GValue,
-			  priv->property_values->len - 1);
-    memset (val, 0, sizeof (GValue));
-    g_value_init (val, G_VALUE_TYPE (value));
-    g_value_copy (value, val);
-    g_hash_table_insert (priv->changed_properties, (gpointer)key, val);
+    g_hash_table_insert (priv->changed_properties, (gpointer) key,
+                         tp_g_value_slice_dup (value));
 #else
     GHashTable *properties;
 
@@ -1900,8 +1889,6 @@ _mcd_account_finalize (GObject *object)
     DEBUG ("%p (%s)", object, priv->unique_name);
     if (priv->changed_properties)
 	g_hash_table_destroy (priv->changed_properties);
-    if (priv->property_values)
-	g_array_free (priv->property_values, TRUE);
     if (priv->properties_source != 0)
 	g_source_remove (priv->properties_source);
 
-- 
1.5.6.5