From 1dc69ec3245de3288b8d5fddcc1751618942869c Mon Sep 17 00:00:00 2001
From: Eileen McNaughton <emcnaughton@wikimedia.org>
Date: Mon, 29 Nov 2021 14:30:24 +1300
Subject: [PATCH] Ensure separation,tag are assigned to the template

---
 CRM/Activity/Form/Activity.php           | 13 +++++++++++++
 CRM/Core/Form.php                        |  4 ++++
 templates/CRM/Activity/Form/Activity.tpl |  4 ++--
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/CRM/Activity/Form/Activity.php b/CRM/Activity/Form/Activity.php
index ac0ba84bec..79a557629b 100644
--- a/CRM/Activity/Form/Activity.php
+++ b/CRM/Activity/Form/Activity.php
@@ -515,6 +515,19 @@ class CRM_Activity_Form_Activity extends CRM_Contact_Form_Task {
     }
   }
 
+  /**
+   * Get any smarty elements that may not be present in the form.
+   *
+   * To make life simpler for smarty we ensure they are set to null
+   * rather than unset. This is done at the last minute when $this
+   * is converted to an array to be assigned to the form.
+   *
+   * @return array
+   */
+  public function getOptionalQuickFormElements(): array {
+    return ['separation', 'tag'];
+  }
+
   /**
    * Set default values for the form.
    *
diff --git a/CRM/Core/Form.php b/CRM/Core/Form.php
index 68574f3aa6..fff2e0ac49 100644
--- a/CRM/Core/Form.php
+++ b/CRM/Core/Form.php
@@ -1072,6 +1072,10 @@ class CRM_Core_Form extends HTML_QuickForm_Page {
   /**
    * Add an optional element to the optional elements array.
    *
+   * These elements are assigned as empty (null) variables if
+   * there is no real field - allowing smarty to use them without
+   * notices.
+   *
    * @param string $elementName
    */
   public function addOptionalQuickFormElement(string $elementName): void {
diff --git a/templates/CRM/Activity/Form/Activity.tpl b/templates/CRM/Activity/Form/Activity.tpl
index 6be2f9672c..4718ad5739 100644
--- a/templates/CRM/Activity/Form/Activity.tpl
+++ b/templates/CRM/Activity/Form/Activity.tpl
@@ -63,7 +63,7 @@
     </td>
   </tr>
 
-  {if !empty($form.separation)}
+  {if $form.separation}
     <tr class="crm-activity-form-block-separation crm-is-multi-activity-wrapper">
       <td class="label">{$form.separation.label}</td>
       <td>{$form.separation.html} {help id="separation"}</td>
@@ -156,7 +156,7 @@
     <td class="label">{$form.result.label}</td><td class="view-value">{$form.result.html}</td>
   </tr>
   {/if}
-  {if !empty($form.tag.html)}
+  {if $form.tag}
   <tr class="crm-activity-form-block-tag">
     <td class="label">{$form.tag.label}</td>
     <td class="view-value">
-- 
2.25.1