Add a null check to prevent NullPointerException am: 10039a4753

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/11702815

Change-Id: Ifb1a34a9edef90fdf3220c51dea1e044af5d9c9d

2 files changed, 5 insertions, 1 deletions

diff --git a/src/com/android/server/connectivity/NetworkMonitor.java b/src/com/android/server/connectivity/NetworkMonitor.java
index 4e56842..d0f62b2 100755
--- a/src/com/android/server/connectivity/NetworkMonitor.java
+++ b/src/com/android/server/connectivity/NetworkMonitor.java
@@ -1731,6 +1731,7 @@ public class NetworkMonitor extends StateMachine {
         }
         try {
             final List<CellInfo> cells = mTelephonyManager.getAllCellInfo();
+            if (cells == null) return null;
             final Map<String, Integer> countryCodeMap = new HashMap<>();
             int maxCount = 0;
             for (final CellInfo cell : cells) {
diff --git a/tests/unit/src/com/android/server/connectivity/NetworkMonitorTest.java b/tests/unit/src/com/android/server/connectivity/NetworkMonitorTest.java
index c02d968..2422b77 100644
--- a/tests/unit/src/com/android/server/connectivity/NetworkMonitorTest.java
+++ b/tests/unit/src/com/android/server/connectivity/NetworkMonitorTest.java
@@ -866,12 +866,15 @@ public class NetworkMonitorTest {
         doReturn(PackageManager.PERMISSION_GRANTED).when(mContext).checkPermission(
                 eq(android.Manifest.permission.ACCESS_FINE_LOCATION),  anyInt(), anyInt());
         doReturn(new ContextWrapper(mContext)).when(mContext).createConfigurationContext(any());
+        doReturn(null).when(mTelephony).getAllCellInfo();
+        assertNull(wnm.getLocationMcc());
         // Prepare CellInfo and check if the vote mechanism is working or not.
         final List<CellInfo> cellList = new ArrayList<CellInfo>();
+        doReturn(cellList).when(mTelephony).getAllCellInfo();
+        assertNull(wnm.getLocationMcc());
         cellList.add(makeTestCellInfoGsm("460"));
         cellList.add(makeTestCellInfoGsm("460"));
         cellList.add(makeTestCellInfoLte("466"));
-        doReturn(cellList).when(mTelephony).getAllCellInfo();
         // The count of 460 is 2 and the count of 466 is 1, so the getLocationMcc() should return
         // 460.
         assertEquals("460", wnm.getLocationMcc());