qt4: a few stability fixes when working as a dialogs provider, needs a lot more ...

modules/gui/qt4/input_manager.cpp

@@ -261,6 +261,8 @@ MainInputManager::~MainInputManager()
 
 void MainInputManager::updateInput()
 {
+    if( VLC_OBJECT_INTF == p_intf->i_object_type )
+    {
         vlc_mutex_lock( &p_intf->change_lock );
         if( p_input && p_input->b_dead )
         {
@@ -282,6 +284,17 @@ void MainInputManager::updateInput()
             QPL_UNLOCK;
         }
         vlc_mutex_unlock( &p_intf->change_lock );
+    }
+    else {
+        /* we are working as a dialogs provider */
+        playlist_t *p_playlist = (playlist_t *) vlc_object_find( p_intf, 
+                                              VLC_OBJECT_PLAYLIST, FIND_ANYWHERE );
+        if( p_playlist )
+        {
+            p_input = p_playlist->p_input;
+            emit inputChanged( p_input );
+        }
+    }
 }
 
 void MainInputManager::stop()

modules/gui/qt4/qt4.hpp

@@ -54,7 +54,7 @@ struct intf_sys_t
 #define QPL_UNLOCK vlc_mutex_unlock( &THEPL->object_lock );
 
 #define THEDP DialogsProvider::getInstance()
-#define THEMIM MainInputManager::getInstance( NULL )
+#define THEMIM MainInputManager::getInstance( p_intf )
 
 #define qfu( i ) QString::fromUtf8( i )
 #define qtr( i ) QString::fromUtf8( _(i) )