better fix for not scrolling textarea

app/assets/javascripts/related_tag.js

@@ -226,9 +226,7 @@
       Danbooru.RelatedTag.process_artist(Danbooru.RelatedTag.recent_artist);
     }
 
-    if ($(window).scrollTop() <= $field.offset().top) {
-      $field.focus();
-    }
+    $field.focusWithoutScroll();
 
     e.preventDefault();
   }

app/assets/javascripts/utility.js

@@ -103,4 +103,11 @@
     this.selectRange(this.val().length, this.val().length);
     return this;
   }
+
+  $.fn.focusWithoutScroll = function(){
+    var x = window.scrollX;
+    var y = window.scrollY;
+    this.focus();
+    window.scrollTo(x, y);
+  };
 })();