From 0051b44a09d67b50b548320233bb8d96d5c8018f Mon Sep 17 00:00:00 2001
From: Mathieu Trudel-Lapierre <mathieu.tl@gmail.com>
Date: Wed, 2 Nov 2011 15:05:43 -0500
Subject: [PATCH] dns: don't update routing and DNS if no devices were ever
 managed

Avoids blowing away existing routes and resolv.conf if NM never
managed any devices.
---
 src/dns-manager/nm-dns-manager.c | 21 +++++++++++++--------
 src/nm-policy.c                  |  9 +++++++++
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/dns-manager/nm-dns-manager.c b/src/dns-manager/nm-dns-manager.c
index 0203f2bb8..ddfd47c84 100644
--- a/src/dns-manager/nm-dns-manager.c
+++ b/src/dns-manager/nm-dns-manager.c
@@ -1097,15 +1097,20 @@ dispose (GObject *object)
 		g_slist_free (priv->plugins);
 		priv->plugins = NULL;
 
-		/* If we're quitting leave a valid resolv.conf in place, not one
-		 * pointing to 127.0.0.1 if any plugins were active.  Thus update
-		 * DNS after disposing of all plugins.
+		/* If last_iface is NULL, this means we haven't done a DNS update before,
+		 * so no reason to try and take down entries from resolv.conf.
 		 */
-		if (!update_dns (self, priv->last_iface, TRUE, &error)) {
-			nm_log_warn (LOGD_DNS, "could not commit DNS changes on shutdown: (%d) %s",
-					     error ? error->code : -1,
-					     error && error->message ? error->message : "(unknown)");
-			g_clear_error (&error);
+		if (priv->last_iface != NULL) {
+			/* If we're quitting leave a valid resolv.conf in place, not one
+			 * pointing to 127.0.0.1 if any plugins were active.  Thus update
+			 * DNS after disposing of all plugins.
+			 */
+			if (!update_dns (self, priv->last_iface, TRUE, &error)) {
+				nm_log_warn (LOGD_DNS, "could not commit DNS changes on shutdown: (%d) %s",
+				             error ? error->code : -1,
+				             error && error->message ? error->message : "(unknown)");
+				g_clear_error (&error);
+			}
 		}
 
 		g_slist_foreach (priv->configs, (GFunc) g_object_unref, NULL);
diff --git a/src/nm-policy.c b/src/nm-policy.c
index 5c4059e10..a1e13f67f 100644
--- a/src/nm-policy.c
+++ b/src/nm-policy.c
@@ -1023,6 +1023,15 @@ device_state_changed (NMDevice *device,
 		update_routing_and_dns (policy, FALSE);
 		break;
 	case NM_DEVICE_STATE_UNMANAGED:
+		if (   old_state == NM_DEVICE_STATE_UNAVAILABLE
+		    || old_state == NM_DEVICE_STATE_DISCONNECTED) {
+			/* If the device was never activated, there's no point in
+			 * updating routing or DNS.  This allows us to keep the previous
+			 * resolv.conf or routes from before NM started if no device was
+			 * ever managed by NM.
+			 */
+			break;
+		}
 	case NM_DEVICE_STATE_UNAVAILABLE:
 		update_routing_and_dns (policy, FALSE);
 		break;