Bug 894454 - Avoid potential NullPointerException crashes in sutAgent; r=wlach

build/mobile/sutagent/android/CmdWorkerThread.java

@@ -139,6 +139,10 @@ public class CmdWorkerThread extends Thread
                     SUTAgentAndroid.log(dc, message);
 
                     outputLine = dc.processCommand(inputLine, out, in, cmdOut);
+                    if (outputLine == null)
+                        {
+                        outputLine = "";
+                        }
                     if (outputLine.length() > 0)
                         {
                         out.print(outputLine + "\n" + prompt);

build/mobile/sutagent/android/DataWorkerThread.java

@@ -170,6 +170,10 @@ public class DataWorkerThread extends Thread
                     if ((inputLine += readLine(in)) != null)
                         {
                         outputLine = dc.processCommand(inputLine, out, in, cmdOut);
+                        if (outputLine == null)
+                            {
+                            outputLine = "";
+                            }
                         out.print(outputLine + "\n");
                         out.flush();
                         if (outputLine.equals("exit"))

build/mobile/sutagent/android/DoCommand.java

@@ -107,7 +107,7 @@ public class DoCommand {
     String ffxProvider = "org.mozilla.ffxcp";
     String fenProvider = "org.mozilla.fencp";
 
-    private final String prgVersion = "SUTAgentAndroid Version 1.18";
+    private final String prgVersion = "SUTAgentAndroid Version 1.19";
 
     public enum Command
         {
@@ -1396,7 +1396,7 @@ private void CancelNotification()
             }
         Log.e("SUTAgentAndroid", "ERROR: Cannot access world writeable test root");
 
-        return(null);
+        return sErrorPrefix + " unable to determine test root";
         }
 
     public String GetAppRoot(String AppName)