tunnel: check for null sourcebuild6

1 files changed, 5 insertions, 1 deletions

diff --git a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
index 9c96e00f..7b1d94fd 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
@@ -422,7 +422,11 @@ public final class GoBackend implements Backend {
         }
 
         LibwgGrpc.LibwgBlockingStub stub = LibwgGrpc.newBlockingStub(channel);
-        DhcpRequest request = DhcpRequest.newBuilder().setSource(source).build();
+        DhcpRequest.Builder requestBuilder = DhcpRequest.newBuilder();
+        if (source != null) {
+            requestBuilder.setSource(source);
+        }
+        DhcpRequest request = requestBuilder.build();
         DhcpResponse resp = stub.dhcp(request);
         Log.i(TAG, "Dhcp: " + resp.getError().getMessage());