Fix kdesktop_lock interaction with DPMS power save

This partially resolves Bug 1475

kdesktop/lock/lockprocess.cc

@@ -130,6 +130,8 @@ Status DPMSInfo ( Display *, CARD16 *, BOOL * );
 #define XF86XK_AudioLowerVolume 0x1008FF11
 #define XF86XK_Display 0x1008FF59
 
+#define DPMS_MONITOR_BLANKED(x) ((x == DPMSModeStandby) || (x == DPMSModeSuspend) || (x == DPMSModeOff))
+
 static Window gVRoot = 0;
 static Window gVRootData = 0;
 static Atom   gXA_VROOT;
@@ -1436,6 +1438,25 @@ bool LockProcess::startLock()
 
 void LockProcess::closeDialogAndStartHack()
 {
+#ifdef HAVE_DPMS
+	if (KDesktopSettings::dpmsDependent()) {
+		BOOL on;
+		CARD16 state;
+		if (DPMSInfo(tqt_xdisplay(), &state, &on)) {
+			//kdDebug() << "checkDPMSActive " << on << " " << state << endl;
+			if (DPMS_MONITOR_BLANKED(state)) {
+				// Make sure saver will attempt to start again after DPMS wakeup
+				// This is related to Bug 1475
+				ENABLE_CONTINUOUS_LOCKDLG_DISPLAY
+				if (mHackStartupEnabled) mHackDelayStartupTimer->start(mHackDelayStartupTimeout, TRUE);
+				// Should not start saver here, because the DPMS check method below would turn it right back off!
+				// This is related to Bug 1475
+				return;
+			}
+		}
+	}
+#endif
+
 	// Close any active dialogs
 	DISABLE_CONTINUOUS_LOCKDLG_DISPLAY
 	mSuspended = true;
@@ -2218,19 +2239,21 @@ void LockProcess::stayOnTop()
 void LockProcess::checkDPMSActive()
 {
 #ifdef HAVE_DPMS
+	if (KDesktopSettings::dpmsDependent()) {
 		BOOL on;
 		CARD16 state;
-    DPMSInfo(tqt_xdisplay(), &state, &on);
+		if (DPMSInfo(tqt_xdisplay(), &state, &on)) {
 			//kdDebug() << "checkDPMSActive " << on << " " << state << endl;
-    if (state == DPMSModeStandby || state == DPMSModeSuspend || state == DPMSModeOff)
-    {
+			if (DPMS_MONITOR_BLANKED(state)) {
 				suspend();
-    } else if ( mSuspended )
-    {
+			}
+			else if (mSuspended) {
 				if (mResizingDesktopLock == false) {
 					resume( true );
 				}
 			}
+		}
+	}
 #endif
 }