Fixed the selectOnClose option

The `selectOnClose` option did not work in production because we
were decorating the `dropdownAdapter` instead of the `resultsAdpater`
when automatically generating the adapters. This has now been fixed,
and the option should work without errors in production.

This also adds documentation for the `selectOnClose` option.

This closes https://github.com/select2/select2/issues/2953.

dist/js/select2.amd.full.js

@@ -3650,13 +3650,6 @@ define('select2/defaults',[
         );
       }
 
-      if (options.selectOnClose) {
-        options.dropdownAdapter = Utils.Decorate(
-          options.dropdownAdapter,
-          SelectOnClose
-        );
-      }
-
       options.dropdownAdapter = Utils.Decorate(
         options.dropdownAdapter,
         AttachBody

dist/js/select2.amd.js

@@ -3650,13 +3650,6 @@ define('select2/defaults',[
         );
       }
 
-      if (options.selectOnClose) {
-        options.dropdownAdapter = Utils.Decorate(
-          options.dropdownAdapter,
-          SelectOnClose
-        );
-      }
-
       options.dropdownAdapter = Utils.Decorate(
         options.dropdownAdapter,
         AttachBody

dist/js/select2.full.js

@@ -4088,13 +4088,6 @@ define('select2/defaults',[
         );
       }
 
-      if (options.selectOnClose) {
-        options.dropdownAdapter = Utils.Decorate(
-          options.dropdownAdapter,
-          SelectOnClose
-        );
-      }
-
       options.dropdownAdapter = Utils.Decorate(
         options.dropdownAdapter,
         AttachBody

dist/js/select2.js

@@ -4088,13 +4088,6 @@ define('select2/defaults',[
         );
       }
 
-      if (options.selectOnClose) {
-        options.dropdownAdapter = Utils.Decorate(
-          options.dropdownAdapter,
-          SelectOnClose
-        );
-      }
-
       options.dropdownAdapter = Utils.Decorate(
         options.dropdownAdapter,
         AttachBody

docs/options.html

@@ -688,6 +688,8 @@ ajax: {
       it will appear in the same location within the DOM as the rest of Select2.
     </p>
 
+    <div class="row">
+      <div class="col-sm-4">
         <dl class="dl-horizontal">
           <dt>Adapter</dt>
           <dd>
@@ -699,6 +701,16 @@ ajax: {
             <code title="select2/dropdown/attachContainer">AttachContainer</code>
           </dd>
         </dl>
+      </div>
+
+      <div class="col-sm-8">
+        <div class="alert alert-warning">
+          <strong>Check your build.</strong> This module is only included in the
+          <a href="index.html#builds-full" class="alert-link">full builds</a> of
+          Select2.
+        </div>
+      </div>
+    </div>
 
     <div class="alert alert-info">
       <strong>
@@ -734,6 +746,30 @@ ajax: {
       A search box is added to the top of the dropdown automatically for select
       boxes where only a single option can be selected.
     </p>
+
+    <h2 id="dropdown-select-on-close">
+      Select the highlighted option on close
+    </h2>
+
+    <p>
+      When users close the dropdown, the last highlighted option can be
+      automatically selected. This is commonly used in combination with
+      <a href="#tags">tagging</a> and <a href="#placeholder">placeholders</a>
+      and other situations where the user is required to select an option, or
+      they need to be able to quickly select multiple options.
+    </p>
+
+    <dl class="dl-horizontal">
+      <dt>Adapter</dt>
+      <dd>
+        <code title="select2/results">ResultsAdapter</code>
+      </dd>
+
+      <dt>Decorator</dt>
+      <dd>
+        <code title="select2/dropdown/selectOnClose">SelectOnClose</code>
+      </dd>
+    </dl>
   </section>
 
   <section id="events">
@@ -1053,7 +1089,8 @@ $.fn.select2.default2.set("theme", "classic");
     </p>
 
     <p>
-      <strong>The compatibility modules are only included in the full builds of
+      <strong>The compatibility modules are only included in the
+      <a href="index.html#builds-full" class="alert-link">full builds</a> of
       Select2</strong>. These files end in <code>.full.js</code>, and the
       compatibility modules are prefixed with <code>select2/compat</code>.
     </p>
@@ -1064,7 +1101,9 @@ $.fn.select2.default2.set("theme", "classic");
 
     <p class="alert alert-warning">
       <a href="announcements-4.0.html#removed-initselection" class="alert-link">Deprecated in Select2 4.0.</a>
-      This has been replaced by another option.
+      This has been replaced by another option and is only available in the
+      <a href="index.html#builds-full" class="alert-link">full builds</a> of
+      Select2.
     </p>
 
     <p>
@@ -1111,7 +1150,9 @@ $.fn.select2.default2.set("theme", "classic");
 
     <p class="alert alert-warning">
       <a href="announcements-4.0.html#query-to-data-adapter" class="alert-link">Deprecated in Select2 4.0.</a>
-      This has been replaced by another option.
+      This has been replaced by another option and is only available in the
+      <a href="index.html#builds-full" class="alert-link">full builds</a> of
+      Select2.
     </p>
 
     <p>

src/js/select2/defaults.js

@@ -128,6 +128,13 @@ define([
           HidePlaceholder
         );
       }
+
+      if (options.selectOnClose) {
+        options.resultsAdapter = Utils.Decorate(
+          options.resultsAdapter,
+          SelectOnClose
+        );
+      }
     }
 
     if (options.dropdownAdapter == null) {
@@ -146,13 +153,6 @@ define([
         );
       }
 
-      if (options.selectOnClose) {
-        options.dropdownAdapter = Utils.Decorate(
-          options.dropdownAdapter,
-          SelectOnClose
-        );
-      }
-
       options.dropdownAdapter = Utils.Decorate(
         options.dropdownAdapter,
         AttachBody