Fix various instance checks

The g_return*_if_fail() calls should use PREFIX_IS_TYPE_NAME [1], which
returns whether the given instance is of the right type, not
PREFIX_TYPE_NAME [2], which checks whether the given instance if of the
right type, warns if not, and returns the passed-in instance unchanged.

Using the wrong one means the returned value is the passed-in pointer,
and thus passes the g_return*_if_fail() whenever the pointer is
non-NULL, no matter whether it's of the right type or not.

A warning would still be emitted by g_type_check_instance_cast(), but
the execution wouldn't get short-circuited.

[1] calls g_type_check_instance_is_a()
[2] calls g_type_check_instance_cast()

4 files changed, 7 insertions, 7 deletions

diff --git a/mate-volume-control/gvc-balance-bar.c b/mate-volume-control/gvc-balance-bar.c
index e4fccb8..3e28345 100644
--- a/mate-volume-control/gvc-balance-bar.c
+++ b/mate-volume-control/gvc-balance-bar.c
@@ -242,7 +242,7 @@ find_stream_lfe_channel (MateMixerStreamControl *control)
 static void
 gvc_balance_bar_set_control (GvcBalanceBar *bar, MateMixerStreamControl *control)
 {
-        g_return_if_fail (GVC_BALANCE_BAR (bar));
+        g_return_if_fail (GVC_IS_BALANCE_BAR (bar));
         g_return_if_fail (MATE_MIXER_IS_STREAM_CONTROL (control));
 
         if (bar->priv->control != NULL) {
diff --git a/mate-volume-control/gvc-level-bar.c b/mate-volume-control/gvc-level-bar.c
index 0d815fc..24ac1f2 100644
--- a/mate-volume-control/gvc-level-bar.c
+++ b/mate-volume-control/gvc-level-bar.c
@@ -295,7 +295,7 @@ void
 gvc_level_bar_set_peak_adjustment (GvcLevelBar   *bar,
                                    GtkAdjustment *adjustment)
 {
-        g_return_if_fail (GVC_LEVEL_BAR (bar));
+        g_return_if_fail (GVC_IS_LEVEL_BAR (bar));
         g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 
         if (bar->priv->peak_adjustment != NULL) {
@@ -321,7 +321,7 @@ void
 gvc_level_bar_set_rms_adjustment (GvcLevelBar   *bar,
                                   GtkAdjustment *adjustment)
 {
-        g_return_if_fail (GVC_LEVEL_BAR (bar));
+        g_return_if_fail (GVC_IS_LEVEL_BAR (bar));
         g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 
         if (bar->priv->rms_adjustment != NULL) {
diff --git a/mate-volume-control/gvc-stream-applet-icon.c b/mate-volume-control/gvc-stream-applet-icon.c
index d2b7337..7c1bdb5 100644
--- a/mate-volume-control/gvc-stream-applet-icon.c
+++ b/mate-volume-control/gvc-stream-applet-icon.c
@@ -497,7 +497,7 @@ void
 gvc_stream_applet_icon_set_display_name (GvcStreamAppletIcon *icon,
                                          const gchar         *name)
 {
-        g_return_if_fail (GVC_STREAM_APPLET_ICON (icon));
+        g_return_if_fail (GVC_IS_STREAM_APPLET_ICON (icon));
 
         g_free (icon->priv->display_name);
 
@@ -511,7 +511,7 @@ void
 gvc_stream_applet_icon_set_control (GvcStreamAppletIcon    *icon,
                                     MateMixerStreamControl *control)
 {
-        g_return_if_fail (GVC_STREAM_APPLET_ICON (icon));
+        g_return_if_fail (GVC_IS_STREAM_APPLET_ICON (icon));
 
         if (icon->priv->control == control)
                 return;
diff --git a/mate-volume-control/gvc-stream-status-icon.c b/mate-volume-control/gvc-stream-status-icon.c
index 8ca2849..aac39ba 100644
--- a/mate-volume-control/gvc-stream-status-icon.c
+++ b/mate-volume-control/gvc-stream-status-icon.c
@@ -508,7 +508,7 @@ void
 gvc_stream_status_icon_set_display_name (GvcStreamStatusIcon *icon,
                                          const gchar         *name)
 {
-        g_return_if_fail (GVC_STREAM_STATUS_ICON (icon));
+        g_return_if_fail (GVC_IS_STREAM_STATUS_ICON (icon));
 
         g_free (icon->priv->display_name);
 
@@ -522,7 +522,7 @@ void
 gvc_stream_status_icon_set_control (GvcStreamStatusIcon    *icon,
                                     MateMixerStreamControl *control)
 {
-        g_return_if_fail (GVC_STREAM_STATUS_ICON (icon));
+        g_return_if_fail (GVC_IS_STREAM_STATUS_ICON (icon));
 
         if (icon->priv->control == control)
                 return;