Changed: ViewConverterBuilder#toAttribute now passes `model.Documen…

…tFragment` to `data.output` if was converter from view element.

src/conversion/buildviewconverter.js

@@ -8,6 +8,7 @@
  */
 
 import Matcher from '../view/matcher';
+import ModelDocumentFragment from '../model/documentfragment';
 import ModelElement from '../model/element';
 import ModelPosition from '../model/position';
 import modelWriter from '../model/writer';
@@ -366,7 +367,8 @@ class ViewConverterBuilder {
 					// Since we are converting to attribute we need an output on which we will set the attribute.
 					// If the output is not created yet, we will create it.
 					if ( !data.output ) {
-						data.output = conversionApi.convertChildren( data.input, consumable, data );
+						const children = conversionApi.convertChildren( data.input, consumable, data );
+						data.output = new ModelDocumentFragment( children );
 					}
 
 					// Use attribute creator function, if provided.

tests/conversion/buildviewconverter.js

@@ -392,6 +392,16 @@ describe( 'View converter builder', () => {
 		expect( modelToString( conversionResult ) ).to.equal( '<span transformer="megatron">foo</span>' );
 	} );
 
+	it( 'should return model document fragment when converting attributes on text', () => {
+		buildViewConverter().for( dispatcher ).fromElement( 'strong' ).toAttribute( 'bold', true );
+
+		let viewElement = new ViewAttributeElement( 'strong', null, new ViewText( 'foo' ) );
+
+		let conversionResult = dispatcher.convert( viewElement, objWithContext );
+
+		expect( conversionResult.is( 'documentFragment' ) ).to.be.true;
+	} );
+
 	it( 'should set different priorities for `toElement` and `toAttribute` conversion', () => {
 		buildViewConverter().for( dispatcher )
 			.fromAttribute( 'class' )