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);
 		},