Don't crash or wtf if the interface doesn't exist.

This prevents the code from issuing a Log.wtf due to calling
transitionTo in ClearingIpAddressesState#enter if the interface
does not exist when IpClient starts provisioning is called.

This prevents IpClientIntegrationTest from crashing on eng builds
due to the Log.wtf being unhandled.

Bug: 155005801
Bug: 152723363
Test: atest NetworkStackNextIntegrationTests:IpClientIntegrationTest#testRestoreInitialInterfaceMtu_NotFoundInterfaceWhenStartingProvisioning
Original-Change: http://aosp/1290575
Merged-In: I4f34343816202c996f9227b72d453ea4a464f4b8
Change-Id: I4f34343816202c996f9227b72d453ea4a464f4b8

1 files changed, 13 insertions, 11 deletions

diff --git a/src/android/net/ip/IpClient.java b/src/android/net/ip/IpClient.java
index 86d3ba7..6021c6a 100644
--- a/src/android/net/ip/IpClient.java
+++ b/src/android/net/ip/IpClient.java
@@ -1699,25 +1699,27 @@ public class IpClient extends StateMachine {
     class ClearingIpAddressesState extends State {
         @Override
         public void enter() {
-            if (readyToProceed()) {
-                deferMessage(obtainMessage(CMD_ADDRESSES_CLEARED));
-            } else {
-                // Clear all IPv4 and IPv6 before proceeding to RunningState.
-                // Clean up any leftover state from an abnormal exit from
-                // tethering or during an IpClient restart.
-                stopAllIP();
-            }
-
             // Ensure that interface parameters are fetched on the handler thread so they are
             // properly ordered with other events, such as restoring the interface MTU on teardown.
             mInterfaceParams = mDependencies.getInterfaceParams(mInterfaceName);
             if (mInterfaceParams == null) {
                 logError("Failed to find InterfaceParams for " + mInterfaceName);
                 doImmediateProvisioningFailure(IpManagerEvent.ERROR_INTERFACE_NOT_FOUND);
-                transitionTo(mStoppedState);
+                deferMessage(obtainMessage(CMD_STOP));
                 return;
             }
+
             mLinkObserver.setInterfaceParams(mInterfaceParams);
+
+            if (readyToProceed()) {
+                deferMessage(obtainMessage(CMD_ADDRESSES_CLEARED));
+            } else {
+                // Clear all IPv4 and IPv6 before proceeding to RunningState.
+                // Clean up any leftover state from an abnormal exit from
+                // tethering or during an IpClient restart.
+                stopAllIP();
+            }
+
             mCallback.setNeighborDiscoveryOffload(true);
         }
 
@@ -1752,7 +1754,7 @@ public class IpClient extends StateMachine {
         }
 
         private boolean readyToProceed() {
-            return (!mLinkProperties.hasIpv4Address() && !mLinkProperties.hasGlobalIpv6Address());
+            return !mLinkProperties.hasIpv4Address() && !mLinkProperties.hasGlobalIpv6Address();
         }
     }