From aa8f8f33b566eee077f85729c1200a88228ac853 Mon Sep 17 00:00:00 2001
From: Erik Kline <ek@google.com>
Date: Fri, 14 Aug 2015 12:16:55 +0900
Subject: [PATCH] Also treat loss of IPv6 as a loss of provisioning.

Bug: 23226635
Change-Id: Icebb7d83ed5b3b796901b9f023909a02eb461941
---
 core/java/android/net/LinkProperties.java                 | 8 ++++++--
 .../coretests/src/android/net/LinkPropertiesTest.java     | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/core/java/android/net/LinkProperties.java b/core/java/android/net/LinkProperties.java
index 6bfa2a495b..1bb0fbb74a 100644
--- a/core/java/android/net/LinkProperties.java
+++ b/core/java/android/net/LinkProperties.java
@@ -119,8 +119,12 @@ public final class LinkProperties implements Parcelable {
             //
             // For one such example of this, see b/18867306.
             //
-            // TODO: Remove this special case altogether.
-            if (before.isIPv4Provisioned() && !after.isIPv4Provisioned()) {
+            // Additionally, losing IPv6 provisioning can result in TCP
+            // connections getting stuck until timeouts fire and other
+            // baffling failures. Therefore, loss of either IPv4 or IPv6 on a
+            // previously dualstack network is deemed a lost of provisioning.
+            if ((before.isIPv4Provisioned() && !after.isIPv4Provisioned()) ||
+                (before.isIPv6Provisioned() && !after.isIPv6Provisioned())) {
                 return ProvisioningChange.LOST_PROVISIONING;
             }
             return ProvisioningChange.STILL_PROVISIONED;
diff --git a/core/tests/coretests/src/android/net/LinkPropertiesTest.java b/core/tests/coretests/src/android/net/LinkPropertiesTest.java
index b6b4f4fa96..d5f632190d 100644
--- a/core/tests/coretests/src/android/net/LinkPropertiesTest.java
+++ b/core/tests/coretests/src/android/net/LinkPropertiesTest.java
@@ -560,10 +560,14 @@ public class LinkPropertiesTest extends TestCase {
         assertTrue(v46lp.isIPv6Provisioned());
         assertTrue(v46lp.isProvisioned());
 
+        assertEquals(ProvisioningChange.STILL_PROVISIONED,
+                LinkProperties.compareProvisioning(v4lp, v46lp));
         assertEquals(ProvisioningChange.STILL_PROVISIONED,
                 LinkProperties.compareProvisioning(v6lp, v46lp));
         assertEquals(ProvisioningChange.LOST_PROVISIONING,
                 LinkProperties.compareProvisioning(v46lp, v6lp));
+        assertEquals(ProvisioningChange.LOST_PROVISIONING,
+                LinkProperties.compareProvisioning(v46lp, v4lp));
 
         // Check that losing and gaining a secondary router does not change
         // the provisioning status.