fix mailru/FileAPI#311 uncaught exception in IE10-11 when FormData#append(gt4GB)

Author: Octane

lib/FileAPI.Form.js

@@ -129,19 +129,38 @@
 if( file.blob && file.blob.toBlob ){
 queue.inc();
 _convertFile(file, function (file, blob){
-data.append(file.name, blob, file.file);
+try{
+// FromData#append throws exception in IE10-11,
+// when a file size is larger than 4GB
+data.append(file.name, blob, file.file);
+}catch( err1 ){
+data._error = err1;
+}
+
 queue.next();
 });
 }
-else if( file.file ){
-data.append(file.name, file.blob, file.file);
-}
-else {
-data.append(file.name, file.blob);
+else{
+try{
+if( file.file ){
+data.append(file.name, file.blob, file.file);
+}
+else{
+data.append(file.name, file.blob);
+}
+}
+catch( err2 ){
+data._error = err2;
+}
 }
 
 if( file.file ){
-data.append('_'+file.name, file.file);
+try{
+data.append('_'+file.name, file.file);
+}
+catch( err3 ){
+data._error = err3;
+}
 }
 });
 },

lib/FileAPI.XHR.js

@@ -71,9 +71,16 @@
 var _this = this, options = this.options;
 
 FormData.toData(function (data){
-// Start uploading
-options.upload(options, _this);
-_this._send.call(_this, options, data);
+
+if( data._error ){
+_this.end(0, data._error.message);
+}
+else{
+// Start uploading
+options.upload(options, _this);
+_this._send.call(_this, options, data);
+}
+
 }, options);
 },