Also SerialDiscovery was affected by bug found at 40535df. Fixes #2892

Author: Federico Fissore

arduino-core/src/cc/arduino/packages/discoverers/serial/SerialBoardsLister.java

@@ -55,6 +55,10 @@ public void start(Timer timer) {
 
   @Override
   public void run() {
+    if (BaseNoGui.packages == null) {
+      return;
+    }
+
     Platform platform = BaseNoGui.getPlatform();
     if (platform == null) {
       return;

arduino-core/src/processing/app/linux/Platform.java

@@ -122,6 +122,7 @@ public String getName() {
 
   @Override
   public Map<String, Object> resolveDeviceAttachedTo(String serial, Map<String, TargetPackage> packages, String devicesListOutput) {
+    assert packages != null;
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     Executor executor = new CollectStdOutExecutor(baos);
 

arduino-core/src/processing/app/macosx/Platform.java

@@ -191,6 +191,7 @@ public String getName() {
 
   @Override
   public Map<String, Object> resolveDeviceAttachedTo(String serial, Map<String, TargetPackage> packages, String devicesListOutput) {
+    assert packages != null;
     if (devicesListOutput == null) {
       return super.resolveDeviceAttachedTo(serial, packages, devicesListOutput);
     }

arduino-core/src/processing/app/windows/Platform.java

@@ -286,6 +286,7 @@ public String getName() {
 
   @Override
   public Map<String, Object> resolveDeviceAttachedTo(String serial, Map<String, TargetPackage> packages, String devicesListOutput) {
+    assert packages != null;
     if (devicesListOutput == null) {
       return super.resolveDeviceAttachedTo(serial, packages, devicesListOutput);
     }