Keep more accurate track of media status changes.

AutoConfigLooper now remembers the last media state it received from the device,
and compares both to see if the active state actually changed. Should help with
quality changes where the link didn't actually drop. May also help on ethernet
if the chipset sends spurious link status change notifications.

src/servers/net/AutoconfigLooper.cpp

@@ -32,7 +32,8 @@ AutoconfigLooper::AutoconfigLooper(BMessenger target, const char* device)
 	: BLooper(device),
 	fTarget(target),
 	fDevice(device),
-	fCurrentClient(NULL)
+	fCurrentClient(NULL),
+	fLastMediaStatus(0)
 {
 	BMessage ready(kMsgReadyToRun);
 	PostMessage(&ready);
@@ -148,11 +149,12 @@ AutoconfigLooper::MessageReceived(BMessage* message)
 				|| message->FindInt32("media", &media) != B_OK)
 				break;
 
-			if ((media & IFM_ACTIVE) != 0) {
+			if ((fLastMediaStatus & IFM_ACTIVE) != (media & IFM_ACTIVE)) {
 				// Reconfigure the interface when we have a link again
 				_ConfigureIPv4();
 				//_ConfigureIPv6();	// TODO: router advertisement and dhcpv6
 			}
+			fLastMediaStatus = media;
 			break;
 
 		default:

src/servers/net/AutoconfigLooper.h

@@ -34,6 +34,7 @@ private:
 			BMessenger			fTarget;
 			BString				fDevice;
 			AutoconfigClient*	fCurrentClient;
+			int32				fLastMediaStatus;
 };
 
 #endif	// AUTOCONFIG_LOOPER_H