Fix NPE from null cellular subscription displayName

Check for null before calling toString() on possibly null displayName.

Bug: 132391746
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: Iba33501c90ca552c08aaee52d36f1610bd6a6180

1 files changed, 5 insertions, 3 deletions

diff --git a/service/java/com/android/server/wifi/CarrierNetworkConfig.java b/service/java/com/android/server/wifi/CarrierNetworkConfig.java
index 6e754231f..20aac5bc1 100644
--- a/service/java/com/android/server/wifi/CarrierNetworkConfig.java
+++ b/service/java/com/android/server/wifi/CarrierNetworkConfig.java
@@ -249,9 +249,11 @@ public class CarrierNetworkConfig {
 
         // Process the carrier config for each active subscription.
         for (SubscriptionInfo subInfo : subInfoList) {
-            processNetworkConfig(
-                    carrierConfigManager.getConfigForSubId(subInfo.getSubscriptionId()),
-                    subInfo.getDisplayName().toString());
+            CharSequence displayNameCs = subInfo.getDisplayName();
+            String displayNameStr = displayNameCs == null ? "" : displayNameCs.toString();
+            PersistableBundle bundle = carrierConfigManager.getConfigForSubId(
+                    subInfo.getSubscriptionId());
+            processNetworkConfig(bundle, displayNameStr);
         }
     }