Refactor code in effects to use data_priv. Re- Close gh-1244.

src/effects.js

@@ -304,7 +304,7 @@ function defaultPrefilter( elem, props, opts ) {
 
 
 	// show/hide pass
-	dataShow = jQuery._data( elem, "fxshow" ) || jQuery._data( elem, "fxshow", {} );
+	dataShow = data_priv.get( elem, "fxshow" );
 	for ( index in props ) {
 		value = props[ index ];
 		if ( rfxtypes.exec( value ) ) {
@@ -313,20 +313,19 @@ function defaultPrefilter( elem, props, opts ) {
 			if ( value === ( hidden ? "hide" : "show" ) ) {
 
 				// If there is dataShow left over from a stopped hide or show and we are going to proceed with show, we should pretend to be hidden
-				if( value === "show" && dataShow[ index ] !== undefined ) {
+				if( value === "show" && dataShow !== undefined && dataShow[ index ] !== undefined ) {
 					hidden = true;
 				} else {
-				continue;
-			}
+					continue;
+				}
 			}
 			handled.push( index );
 		}
 	}
 
 	length = handled.length;
-	if ( !length ) {
+	if ( length ) {
 		dataShow = data_priv.get( elem, "fxshow" ) || data_priv.access( elem, "fxshow", {} );
-	} else {
 		if ( "hidden" in dataShow ) {
 			hidden = dataShow.hidden;
 		}