guard against race conditions

Author: richardelms

bugsnag/src/main/java/com/bugsnag/Configuration.java

@@ -20,6 +20,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.Collections;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.atomic.AtomicBoolean;
 
@@ -142,7 +143,7 @@ public void setEndpoints(String notify, String sessions) throws IllegalArgumentE
      * @throws IllegalArgumentException if the endpoint configuration is null or if
      *                                  the notify endpoint is empty or null
      */
-    public void setEndpoints(EndpointConfiguration endpointConfiguration) throws IllegalArgumentException {
+    public synchronized void setEndpoints(EndpointConfiguration endpointConfiguration) throws IllegalArgumentException {
         if (endpointConfiguration == null) {
             throw new IllegalArgumentException("Endpoint configuration cannot be null.");
         }
@@ -245,35 +246,35 @@ public void setSessionDelivery(Delivery sessionDelivery) {
     }
 
     public String[] getRedactedKeys() {
-        return redactedKeys;
+        return redactedKeys == null ? null : redactedKeys.clone();
     }
 
     public void setRedactedKeys(String[] redactedKeys) {
-        this.redactedKeys = redactedKeys;
+        this.redactedKeys = redactedKeys == null ? null : redactedKeys.clone();
     }
 
     public String[] getDiscardClasses() {
-        return discardClasses;
+        return discardClasses == null ? null : discardClasses.clone();
     }
 
     public void setDiscardClasses(String[] discardClasses) {
-        this.discardClasses = discardClasses;
+        this.discardClasses = discardClasses == null ? null : discardClasses.clone();
     }
 
     public Set<String> getEnabledReleaseStages() {
-        return enabledReleaseStages;
+        return enabledReleaseStages == null ? null : Collections.unmodifiableSet(enabledReleaseStages);
     }
 
     public void setEnabledReleaseStages(Set<String> enabledReleaseStages) {
         this.enabledReleaseStages = enabledReleaseStages;
     }
 
     public String[] getProjectPackages() {
-        return projectPackages;
+        return projectPackages == null ? null : projectPackages.clone();
     }
 
     public void setProjectPackages(String[] projectPackages) {
-        this.projectPackages = projectPackages;
+        this.projectPackages = projectPackages == null ? null : projectPackages.clone();
     }
 
     public String getReleaseStage() {