Allow 'disabled' HTML attribute on field types

core/Field/Date_Field.php

@@ -10,7 +10,7 @@ class Date_Field extends Field {
 	/**
 	 * {@inheritDoc}
 	 */
-	protected $allowed_attributes = array( 'placeholder', 'autocomplete' );
+	protected $allowed_attributes = array( 'disabled', 'placeholder', 'autocomplete' );
 
 	/**
 	 * The storage format for use in PHP

core/Field/Field.php

@@ -154,7 +154,7 @@ class Field implements Datastore_Holder_Interface {
 	 *
 	 * @var array<string>
 	 */
-	protected $allowed_attributes = array();
+	protected $allowed_attributes = array( 'disabled' );
 
 	/**
 	 * The width of the field.

core/Field/Text_Field.php

@@ -12,5 +12,5 @@ class Text_Field extends Field {
 	/**
 	 * {@inheritDoc}
 	 */
-	protected $allowed_attributes = array( 'list', 'max', 'maxLength', 'min', 'pattern', 'placeholder', 'readOnly', 'step', 'type', 'is', 'inputmode', 'autocomplete' );
+	protected $allowed_attributes = array( 'disabled', 'list', 'max', 'maxLength', 'min', 'pattern', 'placeholder', 'readOnly', 'step', 'type', 'is', 'inputmode', 'autocomplete' );
 }

core/Field/Textarea_Field.php

@@ -10,7 +10,7 @@ class Textarea_Field extends Field {
 	/**
 	 * {@inheritDoc}
 	 */
-	protected $allowed_attributes = array( 'maxLength', 'minLength', 'placeholder', 'readOnly', 'is', 'autocomplete' );
+	protected $allowed_attributes = array( 'disabled', 'maxLength', 'minLength', 'placeholder', 'readOnly', 'is', 'autocomplete' );
 
 	/**
 	 * Number of rows (affects textarea height)