[SB Refactor] Add null checks around network capabilities.

It's still not clear to me how the old code didn't NPE but ag/22820241
started causing some NPEs, because ConnectivityManager specifies that
the NetworkCapabilities from #onCapabilitiesChanged will be non-null
(and the old code didn't check nullability). But, let's fix the crashes
now anyway.

I don't believe we need to fix the new pipeline because I haven't seen
any crash clusters come through.

Fixes: 280169520
Test: atest WifiStatusTrackerTest
Change-Id: I1f100b9d799d220505ac4ebf133ee7aae551f833

2 files changed, 27 insertions, 3 deletions

diff --git a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiStatusTracker.java b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiStatusTracker.java
index adaf4a1d3ab5..c45d77471932 100644
--- a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiStatusTracker.java
+++ b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiStatusTracker.java
@@ -343,7 +343,12 @@ public class WifiStatusTracker {
     }
 
     @Nullable
-    private WifiInfo getMainOrUnderlyingWifiInfo(NetworkCapabilities networkCapabilities) {
+    private WifiInfo getMainOrUnderlyingWifiInfo(
+            @Nullable NetworkCapabilities networkCapabilities) {
+        if (networkCapabilities == null) {
+            return null;
+        }
+
         WifiInfo mainWifiInfo = getMainWifiInfo(networkCapabilities);
         if (mainWifiInfo != null) {
             return mainWifiInfo;
@@ -376,7 +381,10 @@ public class WifiStatusTracker {
     }
 
     @Nullable
-    private WifiInfo getMainWifiInfo(NetworkCapabilities networkCapabilities) {
+    private WifiInfo getMainWifiInfo(@Nullable NetworkCapabilities networkCapabilities) {
+        if (networkCapabilities == null) {
+            return null;
+        }
         boolean canHaveWifiInfo = networkCapabilities.hasTransport(TRANSPORT_WIFI)
                 || networkCapabilities.hasTransport(TRANSPORT_CELLULAR);
         if (!canHaveWifiInfo) {
@@ -402,7 +410,11 @@ public class WifiStatusTracker {
                 getMainOrUnderlyingWifiInfo(networkCapabilities));
     }
 
-    private boolean connectionIsWifi(NetworkCapabilities networkCapabilities, WifiInfo wifiInfo) {
+    private boolean connectionIsWifi(
+            @Nullable NetworkCapabilities networkCapabilities, WifiInfo wifiInfo) {
+        if (networkCapabilities == null) {
+            return false;
+        }
         return wifiInfo != null || networkCapabilities.hasTransport(TRANSPORT_WIFI);
     }
 
diff --git a/packages/SettingsLib/tests/robotests/src/com/android/settingslib/wifi/WifiStatusTrackerTest.java b/packages/SettingsLib/tests/robotests/src/com/android/settingslib/wifi/WifiStatusTrackerTest.java
index 6e975cf9d8f3..5a9a9d154070 100644
--- a/packages/SettingsLib/tests/robotests/src/com/android/settingslib/wifi/WifiStatusTrackerTest.java
+++ b/packages/SettingsLib/tests/robotests/src/com/android/settingslib/wifi/WifiStatusTrackerTest.java
@@ -305,4 +305,16 @@ public class WifiStatusTrackerTest {
 
         assertThat(mWifiStatusTracker.isDefaultNetwork).isTrue();
     }
+
+    /** Regression test for b/280169520. */
+    @Test
+    public void networkCallbackNullCapabilities_noCrash() {
+        Network primaryNetwork = Mockito.mock(Network.class);
+
+        // WHEN the network capabilities are null
+        mNetworkCallbackCaptor.getValue().onCapabilitiesChanged(
+                primaryNetwork, /* networkCapabilities= */ null);
+
+        // THEN there's no crash (no assert needed)
+    }
 }