Dialog: Fix shift-tab handling, focus the correct element

Copy-paste error introduced in df6110c0d424ff3306fdd5576011f2dcf4d242d0

Updates the tabbing test to be more specific about which element should
have focus, instead of only checking if focus is within the dialog.

Ref #9646
Ref #10103
Closes gh-1264

1 files changed, 1 insertions, 1 deletions

diff --git a/ui/dialog.js b/ui/dialog.js
index 358000881..7998b042c 100644
--- a/ui/dialog.js
+++ b/ui/dialog.js
@@ -348,7 +348,7 @@ return $.widget( "ui.dialog", {
 					event.preventDefault();
 				} else if ( ( event.target === first[0] || event.target === this.uiDialog[0] ) && event.shiftKey ) {
 					this._delay(function() {
-						first.focus();
+						last.focus();
 					});
 					event.preventDefault();
 				}