fix export of bad pads and also limit import to files

src/node/utils/ExportEtherpad.js

@@ -48,7 +48,7 @@ exports.getPadRaw = function(padId, callback){
 
               // Get the author info
               db.get("globalAuthor:"+authorId, function(e, authorEntry){
-                authorEntry.padIDs = padId;
+                if(authorEntry && authorEntry.padIDs) authorEntry.padIDs = padId;
                 if(!e) data["globalAuthor:"+authorId] = authorEntry;
               });
 

src/node/utils/ImportEtherpad.js

@@ -21,9 +21,22 @@ var db = require("../db/DB").db;
 exports.setPadRaw = function(padId, records, callback){
   records = JSON.parse(records);
 
+  // !! HACK !!
+  // If you have a really large pad it will cause a Maximum Range Stack crash
+  // This is a temporary patch for that so things are kept stable.
+  var recordCount = Object.keys(records).length;
+  if(recordCount >= 50000){
+    console.warn("Etherpad file is too large to import..  We need to fix this.  See https://github.com/ether/etherpad-lite/issues/2524");
+    return callback("tooLarge", false);
+  }
+
   async.eachSeries(Object.keys(records), function(key, cb){
     var value = records[key]
 
+    if(!value){
+      cb(); // null values are bad.
+    }
+
     // Author data
     if(value.padIDs){
       // rewrite author pad ids
@@ -34,7 +47,9 @@ exports.setPadRaw = function(padId, records, callback){
       db.get(key, function(err, author){
         if(author){
           // Yes, add the padID to the author..
+          if( Object.prototype.toString.call(author) === '[object Array]'){
             author.padIDs.push(padId);
+          }
           value = author;
         }else{
           // No, create a new array with the author info in