fix ignoring empty delta

lib/ace/document.js

@@ -570,7 +570,7 @@ var Document = function(textOrLines) {
     this.applyDelta = function(delta, doNotValidate) {
         var isInsert = delta.action == "insert";
         // An empty range is a NOOP.
-        if (isInsert ? !delta.lines.length
+        if (isInsert ? delta.lines.length <= 1 && !delta.lines[0]
             : !Range.comparePoints(delta.start, delta.end))
             return;
         

lib/ace/document_test.js

@@ -298,6 +298,16 @@ module.exports = {
         assert.equal(doc.$lines.length, 1);
     },
     
+    "test: ignore empty delta": function() {
+        var doc = new Document("");
+        doc.on("change", function() {
+            throw "should ignore empty delta";
+        })
+        doc.insert({row: 0, column: 0}, "");
+        doc.insert({row: 1, column: 1}, "");
+        doc.remove({start: {row: 1, column: 1}, end: {row: 1, column: 1}});
+    },
+    
     "test: inserting huge delta": function() {
         var doc = new Document("");
         var val = "";

lib/ace/worker/mirror.js

@@ -18,11 +18,11 @@ var Mirror = exports.Mirror = function(sender) {
             doc.applyDeltas(data);
         } else {
             for (var i = 0; i < data.length; i += 2) {
-                if (Array.isArray(data[i+1]))
+                if (Array.isArray(data[i+1])) {
                     var d = {action: "insert", start: data[i], lines: data[i+1]};
-                else
+                } else {
-                    var d = {action: "remove", start: data[i],end: data[i+1]};
+                    var d = {action: "remove", start: data[i], end: data[i+1]};
-                
+                }
                 doc.applyDelta(d, true);
             }
         }