Display bug for Checkboxes Custom field on Event Confirm / Thank you pages

On event registration form, check some checkboxes on a checkboxes custom field :

On confirm / thank you, the wrong label is chown :

After digging, the form is passing the submitted $value as something like :

[1 => 0, 2 => 1, 3 => 1]

The "1" is only a boolean but it is interpreted as a checkbox value ($val) in https://github.com/civicrm/civicrm-core/blob/master/CRM/Core/BAO/CustomField.php#L1252 (function displayValue) :

        ...
        elseif (is_array($value)) {
          $v = array();
          foreach ($value as $key => $val) {
            $v[] = CRM_Utils_Array::value($val, $field['options']);
          }
          $display = implode(', ', $v);
        }
        ...

Not sure if we should change this function or the one that send the params in the first place...

Patch that fix the bug but not with a good level of confidence as there is a good chance that it creates regressions somewhere else :

--- a/sites/all/modules/civicrm/CRM/Core/BAO/CustomField.php
+++ b/sites/all/modules/civicrm/CRM/Core/BAO/CustomField.php
@@ -1241,11 +1241,20 @@ class CRM_Core_BAO_CustomField extends CRM_Core_DAO_CustomField {
             $display = $value;
           }
         }
-        elseif (is_array($value)) {
+       elseif (is_array($value)) {
           $v = array();
-          foreach ($value as $key => $val) {
-            $v[] = CRM_Utils_Array::value($val, $field['options']);
-          }
+          if ($field['html_type'] == 'CheckBox') {
+           foreach ($value as $key => $val) {
+              if ($val == 1) {
+                $v[] = CRM_Utils_Array::value($key, $field['options']);
+             }
+           }
+         }
+         else {
+            foreach ($value as $key => $val) {
+              $v[] = CRM_Utils_Array::value($val, $field['options']);
+            }
+         }
           $display = implode(', ', $v);
         }
         else {

Somewhat related : #866 (closed)

As expected, the patch #1058 (comment 19248) is pretty much breaking everything else (participant display, report, ...) so we probably need to fix the data provided to the function instead.

added ~84 needs:concept approval sig:bug triaged labels

I have created a PR that doesn't seem to break anything : https://github.com/civicrm/civicrm-core/pull/14587

changed milestone to %5.16.0

added Concept approved label and removed needs:concept approval label

closed

mentioned in commit c67b54a2

mentioned in commit 4139dd45

mentioned in commit a541c4f3

mentioned in issue #1089 (closed)

Thanks for fixing this one!

mentioned in issue #1099 (closed)