Update DataServiceImpl.java

Solves Problem #166 `merge()` erases the *Latest Position* field. That is why, Markers are disappearing. We have to upgrade the Device Details keeping that very field.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/org/traccar/web/server/model/DataServiceImpl.java b/src/org/traccar/web/server/model/DataServiceImpl.java
index fb8724ae..db10bd5e 100644
--- a/src/org/traccar/web/server/model/DataServiceImpl.java
+++ b/src/org/traccar/web/server/model/DataServiceImpl.java
@@ -339,9 +339,11 @@ public class DataServiceImpl extends RemoteServiceServlet implements DataService
             if (results.isEmpty()) {
                 entityManager.getTransaction().begin();
                 try {
-                    device = entityManager.merge(device);
+                	Device tmp_device = entityManager.find(Device.class, device.getId());
+                    tmp_device.setName(device.getName());
+                    tmp_device.setUniqueId(device.getUniqueId());
                     entityManager.getTransaction().commit();
-                    return device;
+                    return tmp_device;
                 } catch (RuntimeException e) {
                     entityManager.getTransaction().rollback();
                     throw e;