Use `attr` instead of `prop` for `select2-selection__rendered` title (#4640)

See #3895, and jQuery docs on `attr`:

> As of jQuery 1.6, the .prop() method provides a way to explicitly retrieve property values, while .attr() retrieves attributes.

CHANGELOG.md

@@ -8,7 +8,7 @@
 
 ### Bug fixes
 - Add `;` before beginning of factory wrapper (#5089)
-- Clear tooltip from `select2-selection__rendered` when selection is cleared (#4746)
+- Clear tooltip from `select2-selection__rendered` when selection is cleared (#4640, #4746)
 - Fix keyboard not closing when closing dropdown on iOS 10 (#4680)
 - User-defined types not normalized properly when passed in as data (#4632)
 - Fix "the results could not be loaded" displaying during AJAX request (#4356)

src/js/select2/selection/multiple.js

@@ -55,7 +55,7 @@ define([
   };
 
   MultipleSelection.prototype.clear = function () {
-    this.$selection.find('.select2-selection__rendered').empty();
+    this.$selection.find('.select2-selection__rendered').empty().removeAttr('title');
   };
 
   MultipleSelection.prototype.display = function (data, container) {
@@ -93,7 +93,7 @@ define([
       var formatted = this.display(selection, $selection);
 
       $selection.append(formatted);
-      $selection.prop('title', selection.title || selection.text);
+      $selection.attr('title', selection.title || selection.text);
 
       $selection.data('data', selection);
 

src/js/select2/selection/single.js

@@ -66,10 +66,9 @@ define([
   };
 
   SingleSelection.prototype.clear = function () {
-
     var $rendered = this.$selection.find('.select2-selection__rendered');
     $rendered.empty();
-    $rendered.attr('title',''); // clear tooltip on empty
+    $rendered.removeAttr('title'); // clear tooltip on empty
   };
 
   SingleSelection.prototype.display = function (data, container) {
@@ -95,7 +94,7 @@ define([
     var formatted = this.display(selection, $rendered);
 
     $rendered.empty().append(formatted);
-    $rendered.prop('title', selection.title || selection.text);
+    $rendered.attr('title', selection.title || selection.text);
   };
 
   return SingleSelection;