commit 5bf90e8ade8fdde9d31aecabeadf9cc9b00fc7a4
Author: Egbert Eich <eich@freedesktop.org>
Date:   Fri Aug 15 13:02:03 2008 +0200

    RandR: Don't allow adding modes to a disconnected output.
    
    As long as we don't know a device we cannot validate a mode,
    thus we just fail it.
    Fix for: http://bugs.freedesktop.org/show_bug.cgi?id=17136

diff --git a/src/rhd_randr.c b/src/rhd_randr.c
index 0a4bf26..813d79d 100644
--- a/src/rhd_randr.c
+++ b/src/rhd_randr.c
@@ -700,6 +700,8 @@ rhdRROutputModeValid(xf86OutputPtr  out,
     /* If out->crtc is not NULL, it is not necessarily the Crtc that will
      * be used, so let's better skip crtc based checks... */
     /* Monitor is handled by RandR */
+    if (!rout->Output->Connector)
+	return MODE_OUTPUT_UNDEF;
     Status = RHDRRModeFixup(out->scrn, Mode, NULL, rout->Connector,
 			    rout->Output, NULL, rout->ScaledToMode ? TRUE : FALSE);
     RHDDebug(rhdPtr->scrnIndex, "%s: %s: %s\n", __func__,