Fix addPacket replacing existing and then adding duplicate item

src/org/kde/kdeconnect/DevicePacketQueue.java

@@ -41,9 +41,15 @@ class DevicePacketQueue {
     private boolean exit = false;
 
     DevicePacketQueue(Device device) {
+        this(device, true);
+    }
+
+    DevicePacketQueue(Device device, Boolean startThread) {
         mDevice = device;
+        if (startThread) {
             ThreadHelper.execute(new SendingRunnable());
         }
+    }
 
     /**
      * Send a packet (at some point in the future)
@@ -56,20 +62,26 @@ class DevicePacketQueue {
             if (exit) {
                 callback.onFailure(new Exception("Device disconnected!"));
             } else {
+                boolean replaced = false;
+
                 if (replaceID >= 0) {
-                    final Optional<Item> itemOptional = items.stream()
+                    for (Item item : items) {
-                            .filter(item -> item.replaceID == replaceID).findFirst();
+                        if (item.replaceID == replaceID) {
-                    itemOptional.ifPresent(item -> {
-                        //Replace contents with new contents
                             item.packet = packet;
                             item.callback = callback;
-                    });
+                            replaced = true;
+                            break;
                         }
+                    }
+                }
+
+                if (!replaced) {
                     items.addLast(new Item(packet, replaceID, callback));
                     lock.notify();
                 }
             }
         }
+    }
 
     /**
      * Check if we still have an unsent packet in the queue with the given ID.

tests/org/kde/kdeconnect/DevicePacketQueueTest.java

@@ -0,0 +1,50 @@
+package org.kde.kdeconnect;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+import org.mockito.Mockito;
+
+public class DevicePacketQueueTest {
+    @Test
+    public void addPacketWithPositiveReplaceId() {
+        Device device = Mockito.mock(Device.class);
+        Device.SendPacketStatusCallback callback = Mockito.mock(Device.SendPacketStatusCallback.class);
+
+        DevicePacketQueue queue = new DevicePacketQueue(device, false);
+
+        queue.addPacket(new NetworkPacket("Test"), 0, callback);
+        queue.addPacket(new NetworkPacket("Test1"), 1, callback);
+
+        assertNotNull(queue.getAndRemoveUnsentPacket(0));
+        assertNotNull(queue.getAndRemoveUnsentPacket(1));
+    }
+
+    @Test
+    public void addPacketWithNegativeReplaceId() {
+        Device device = Mockito.mock(Device.class);
+        Device.SendPacketStatusCallback callback = Mockito.mock(Device.SendPacketStatusCallback.class);
+
+        DevicePacketQueue queue = new DevicePacketQueue(device, false);
+
+        queue.addPacket(new NetworkPacket("Test"), -1, callback);
+        queue.addPacket(new NetworkPacket("Test1"), -1, callback);
+
+        assertNotNull(queue.getAndRemoveUnsentPacket(-1));
+        assertNotNull(queue.getAndRemoveUnsentPacket(-1));
+    }
+
+    @Test
+    public void addPacketReplacesPacket() {
+        Device device = Mockito.mock(Device.class);
+        Device.SendPacketStatusCallback callback = Mockito.mock(Device.SendPacketStatusCallback.class);
+
+        DevicePacketQueue queue = new DevicePacketQueue(device, false);
+
+        queue.addPacket(new NetworkPacket("Test"), 1, callback);
+        queue.addPacket(new NetworkPacket("Test1"), 1, callback);
+
+        assertNotNull(queue.getAndRemoveUnsentPacket(1));
+        assertNull(queue.getAndRemoveUnsentPacket(1));
+    }
+}