[Esource] Do not set properties on load which did not change

When calling g_object_set(), g_object_set_property() and similar
set functions, the GObject itself notifies about the property change,
even if the value didn't change at all. This was exhibited by false
notifications when (re)loading ESource on a change on all its saved
properties, which, in particular, was causing bug #722399.

diff --git a/libedataserver/e-source.c b/libedataserver/e-source.c
index 1b4077d..4b611d3 100644 (file)
--- a/libedataserver/e-source.c
+++ b/libedataserver/e-source.c
@@ -319,6 +319,69 @@ source_localized_hack (GKeyFile *key_file,
        g_key_file_set_string (key_file, group_name, key, new_value);
 }
 
+static gboolean
+source_check_values_differ (GType g_type,
+                           const GValue *value,
+                           const GValue *value2)
+{
+       gboolean differ = TRUE;
+       GValue *value1;
+
+       g_return_val_if_fail (value != NULL, TRUE);
+       g_return_val_if_fail (value2 != NULL, TRUE);
+
+       value1 = g_slice_new0 (GValue);
+       g_value_init (value1, g_type);
+       g_value_copy (value2, value1);
+
+       if (g_value_transform (value, value1)) {
+               #define check_type(name,get) G_STMT_START { \
+                       if (G_VALUE_HOLDS_ ## name (value1)) { \
+                               differ = g_value_get_ ## get (value1) != g_value_get_ ## get (value2); \
+                               break; \
+                       } } G_STMT_END
+
+               do {
+                       check_type (BOOLEAN, boolean);
+                       check_type (CHAR, char);
+                       check_type (DOUBLE, double);
+                       check_type (ENUM, enum);
+                       check_type (FLAGS, flags);
+                       check_type (FLOAT, float);
+                       check_type (GTYPE, gtype);
+                       check_type (INT, int);
+                       check_type (INT64, int64);
+                       check_type (LONG, long);
+                       check_type (POINTER, pointer);
+                       check_type (UCHAR, uchar);
+                       check_type (UINT, uint);
+                       check_type (UINT64, uint64);
+                       check_type (ULONG, ulong);
+
+                       if (G_VALUE_HOLDS_STRING (value1)) {
+                               differ = g_strcmp0 (g_value_get_string (value1), g_value_get_string (value2)) != 0;
+                               break;
+                       }
+
+                       if (G_VALUE_HOLDS_VARIANT (value1)) {
+                               GVariant *variant1, *variant2;
+
+                               variant1 = g_value_get_variant (value1);
+                               variant2 = g_value_get_variant (value2);
+                               differ = g_variant_compare (variant1, variant2) != 0;
+                               break;
+                       }
+               } while (FALSE);
+
+               #undef check_type
+       }
+
+       g_value_unset (value1);
+       g_slice_free (GValue, value1);
+
+       return differ;
+}
+
 static void
 source_set_key_file_from_property (GObject *object,
                                    GParamSpec *pspec,
@@ -570,7 +633,23 @@ source_set_property_from_key_file (GObject *object,
        }
 
        if (G_IS_VALUE (value)) {
-               g_object_set_property (object, pspec->name, value);
+               GValue *cvalue;
+
+               cvalue = g_slice_new0 (GValue);
+               g_value_init (cvalue, pspec->value_type);
+               g_object_get_property (object, pspec->name, cvalue);
+
+               /* This is because the g_object_set_property() invokes "notify" signal
+                  on the set property, even if the value did not change, which creates
+                  false notifications, which can cause UI or background activities
+                  without any real reason (especially with the ''enabled' property load). */
+               if (!G_IS_VALUE (cvalue) || source_check_values_differ (pspec->value_type, value, cvalue))
+                       g_object_set_property (object, pspec->name, value);
+
+               if (G_IS_VALUE (cvalue))
+                       g_value_unset (cvalue);
+               g_slice_free (GValue, cvalue);
+
                g_value_unset (value);
        }