fix(edge): deliver FEATURE_DISABLED rejection cause instead of masking it with channel-shutdown error

common/edge-api/src/main/java/org/thingsboard/edge/rpc/EdgeGrpcClient.java

@@ -47,6 +47,7 @@ import org.thingsboard.server.gen.edge.v1.UplinkResponseMsg;
 import javax.net.ssl.SSLException;
 import java.net.InetSocketAddress;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Consumer;
 
@@ -153,6 +154,14 @@ public class EdgeGrpcClient implements EdgeRpcClient {
                                                          Consumer<DownlinkMsg> onDownlink,
                                                          Consumer<Exception> onError) {
         return new StreamObserver<>() {
+
+            // Set only when a connection rejection is handled in onNext(). The disconnect() we then
+            // issue shuts down the channel and provokes a generic stream onError; this flag lets that
+            // self-inflicted error be ignored instead of racing ahead of and masking the rejection cause.
+            // A genuine stream failure (onError with no preceding rejection) does not set it and behaves
+            // exactly as before.
+            private final AtomicBoolean terminated = new AtomicBoolean(false);
+
             @Override
             public void onNext(ResponseMsg responseMsg) {
                 if (responseMsg.hasConnectResponseMsg()) {
@@ -166,6 +175,10 @@ public class EdgeGrpcClient implements EdgeRpcClient {
                         onEdgeUpdate.accept(connectResponseMsg.getConfiguration());
                     } else {
                         log.error("[{}] Failed to establish the connection! Code: {}. Error message: {}.", edgeKey, connectResponseMsg.getResponseCode(), connectResponseMsg.getErrorMsg());
+                        // Claim the terminal-error slot before disconnecting: disconnect() shuts down the
+                        // channel, which surfaces a generic stream onError that would otherwise be delivered
+                        // first and mask the application-level cause reported below.
+                        terminated.set(true);
                         try {
                             EdgeGrpcClient.this.disconnect(true);
                         } catch (InterruptedException e) {
@@ -192,6 +205,12 @@ public class EdgeGrpcClient implements EdgeRpcClient {
             @Override
             public void onError(Throwable t) {
                 log.warn("[{}] Stream was terminated due to error:", edgeKey, t);
+                if (terminated.get()) {
+                    // A connection rejection was already reported in onNext(); this is the channel-shutdown
+                    // error provoked by our own disconnect(). Ignore it so it does not mask the real cause.
+                    log.debug("[{}] Ignoring stream termination provoked by rejection handling.", edgeKey);
+                    return;
+                }
                 try {
                     EdgeGrpcClient.this.disconnect(true);
                 } catch (InterruptedException e) {