* x11_display.cpp: support 15bpp mode for X11 skins and avoid a segfault

    when a mode is not supported (closes bug #1809). Move the "main window"
    outside the screen to avoid seeing it in the workspace selector applet.

modules/gui/skins2/x11/x11_display.cpp

@@ -106,6 +106,7 @@ X11Display::X11Display( intf_thread_t *pIntf ): SkinObject( pIntf ),
             m_pixelSize = 1;
             break;
 
+        case 15:
         case 16:
         case 24:
         case 32:
@@ -135,7 +136,7 @@ X11Display::X11Display( intf_thread_t *pIntf ): SkinObject( pIntf ),
                 m_pixelSize = 1;
             }
 
-            if( depth == 16 )
+            if( depth == 15 || depth == 16 )
             {
                 if( order == MSBFirst )
                 {
@@ -180,7 +181,6 @@ X11Display::X11Display( intf_thread_t *pIntf ): SkinObject( pIntf ),
         xgcvalues.graphics_exposures = False;
         m_gc = XCreateGC( m_pDisplay, DefaultRootWindow( m_pDisplay ),
                           GCGraphicsExposures, &xgcvalues );
-    }
 
         // Create a parent window to have a single task in the task bar
         XSetWindowAttributes attr;
@@ -215,6 +215,10 @@ X11Display::X11Display( intf_thread_t *pIntf ): SkinObject( pIntf ),
                              ShapeSet );
         // Map the window
         XMapWindow( m_pDisplay, m_mainWindow);
+
+        // Move it outside the screen to avoid seeing it in workspace selector
+        XMoveWindow( m_pDisplay, m_mainWindow, -10, -10 );
+    }
 }