Issue 5097, issue 5099 - Only retrieve element source from the process actually selecting

lib/child/commands.js

 /*
  * This Source Code is subject to the terms of the Mozilla Public License
  * version 2.0 (the "License"). You can obtain a copy of the License at
  * http://mozilla.org/MPL/2.0/.
  */
 
 "use strict";
 
 let messageManager = require("messageManager");
 let {getNodeInfo} = require("./nodeInfo");
@@ skipping 49 matching lines @@
         type: node.nodeType == node.TEXT_NODE ? "text" : "comment",
         text: node.textContent
       };
       break;
   }
   return result;
 }
 
 function serializeSelected(message)
 {
+  if (!state.selectedElement)
+    return;
+
   messageManager.sendAsyncMessage("ElemHideHelper:Response", {
     messageId: message.data.messageId,
     serialized: serializeNode(state.selectedElement)
   });
 }
 
 function getHTML(message)
 {
+  if (!state.selectedElement)
+    return;
+
   messageManager.sendAsyncMessage("ElemHideHelper:Response", {
     messageId: message.data.messageId,
     html: state.selectedElement.outerHTML,
     baseURI: state.selectedElement.baseURI
   });
 }
 
 function quit()
 {
   stopSelection();
@@ skipping 105 matching lines @@
     counter: 0,
     element: state.selectedElement,
     origVisibility: state.selectedElement.style.visibility,
     timer: Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer)
   };
 
   blinkState.timer.initWithCallback(doBlink, 250,
       Ci.nsITimer.TYPE_REPEATING_SLACK);
 }
 exports.blinkElement = blinkElement;