Kill active programmer if still alive after closing last IDE window

Fixes arduino#7498

Author: facchinm

app/src/processing/app/Base.java

@@ -26,6 +26,7 @@
 import cc.arduino.Constants;
 import cc.arduino.UpdatableBoardsLibsFakeURLsHandler;
 import cc.arduino.UploaderUtils;
+import cc.arduino.packages.Uploader;
 import cc.arduino.contributions.*;
 import cc.arduino.contributions.libraries.*;
 import cc.arduino.contributions.libraries.ui.LibraryManagerUI;
@@ -961,6 +962,14 @@ public boolean handleQuit() {
       // ignore
     }
 
+    // kill uploader (if still alive)
+    UploaderUtils uploaderInstance = new UploaderUtils();
+    Uploader uploader = uploaderInstance.getUploaderByPreferences(false);
+    if (uploader != null && uploader.programmerPid != null && uploader.programmerPid.isAlive()) {
+        // kill the stuck programmer
+        uploader.programmerPid.destroyForcibly();
+    }
+
     if (handleQuitEach()) {
       // Save out the current prefs state
       PreferencesData.save();

arduino-core/src/cc/arduino/packages/Uploader.java

@@ -106,7 +106,7 @@ public String getAuthorizationKey() {
   }
 
   // static field for last executed programmer process ID
-  static protected Process programmerPid;
+  static public Process programmerPid;
 
   protected boolean executeUploadCommand(Collection<String> command) throws Exception {
     return executeUploadCommand(command.toArray(new String[command.size()]));