From d290014d6cace5667c68a73078815c51c85aa425 Mon Sep 17 00:00:00 2001
From: colemanw <coleman@civicrm.org>
Date: Wed, 5 Aug 2026 13:07:30 -0400
Subject: [PATCH] SearchKit - Fix deep joins to custom fields.

Fixes dev/core#6676
---
 ext/search_kit/ang/crmSearchAdmin.module.js   |  4 +-
 .../api/v4/Custom/ContactCustomJoinTest.php   | 83 +++++++++++++++++++
 2 files changed, 85 insertions(+), 2 deletions(-)

diff --git a/ext/search_kit/ang/crmSearchAdmin.module.js b/ext/search_kit/ang/crmSearchAdmin.module.js
index 76267adc91ac..582ac052855b 100644
--- a/ext/search_kit/ang/crmSearchAdmin.module.js
+++ b/ext/search_kit/ang/crmSearchAdmin.module.js
@@ -236,9 +236,9 @@
           if (Array.isArray(condition)) {
             condition.forEach((ref, side) => {
               if (side !== 1 && typeof ref === 'string') {
-                if (ref.includes('.')) {
+                if (ref.includes(join.alias + '.')) {
                   condition[side] = ref.replace(join.alias + '.', alias + '.');
-                } else if (prefix.length && !ref.includes('"') && !ref.includes("'")) {
+                } else if (prefix.length && !ref.startsWith(prefix + '.') && !ref.includes('"') && !ref.includes("'")) {
                   condition[side] = prefix + '.' + ref;
                 }
               }
diff --git a/tests/phpunit/api/v4/Custom/ContactCustomJoinTest.php b/tests/phpunit/api/v4/Custom/ContactCustomJoinTest.php
index bdfa6b9c2c34..ab91c1f5752a 100644
--- a/tests/phpunit/api/v4/Custom/ContactCustomJoinTest.php
+++ b/tests/phpunit/api/v4/Custom/ContactCustomJoinTest.php
@@ -157,4 +157,87 @@ public function testJoinWithCustomFieldComparedToCoreFieldInOnClause(): void {
     $this->assertNull($result[2]['activity.id']);
   }
 
+  /**
+   * Tests custom entityRef field on joined entity in explicit join clause.
+   */
+  public function testJoinWithCustomFieldOnJoinedEntity(): void {
+    $this->createTestRecord('CustomGroup', [
+      'name' => 'Activity_fields',
+      'title' => 'Activity_fields',
+      'extends' => 'Activity',
+      'extends_entity_column_value:name' => ['Meeting'],
+    ]);
+    $this->createTestRecord('CustomField', [
+      'name' => 'Org',
+      'label' => 'Org',
+      'custom_group_id.name' => 'Activity_fields',
+      'html_type' => 'EntityRef',
+      'data_type' => 'EntityReference',
+      'fk_entity' => 'Organization',
+    ]);
+    $org = $this->createTestRecord('Contact', [
+      'contact_type' => 'Organization',
+      'organization_name' => 'Test Organization',
+    ]);
+    $target = $this->createTestRecord('Contact', [
+      'contact_type' => 'Individual',
+      'first_name' => 'Test',
+      'last_name' => 'Target',
+    ]);
+    $this->createTestRecord('Activity', [
+      'activity_type_id:name' => 'Meeting',
+      'subject' => 'Test Meeting',
+      'target_contact_id' => [$target['id']],
+      'Activity_fields.Org' => $org['id'],
+    ]);
+
+    $result = civicrm_api4('Contact', 'get', [
+      'checkPermissions' => FALSE,
+      'select' => [
+        'id',
+        'Contact_ActivityContact_Activity_01.subject',
+        'Contact_ActivityContact_Activity_01_Activity_Organization_Org_01.organization_name',
+      ],
+      'where' => [
+        ['id', '=', $target['id']],
+      ],
+      'join' => [
+        [
+          'Activity AS Contact_ActivityContact_Activity_01',
+          'INNER',
+          'ActivityContact',
+          [
+            'id',
+            '=',
+            'Contact_ActivityContact_Activity_01.contact_id',
+          ],
+          [
+            'Contact_ActivityContact_Activity_01.record_type_id:name',
+            '=',
+            '"Activity Targets"',
+          ],
+          [
+            'Contact_ActivityContact_Activity_01.activity_type_id:name',
+            '=',
+            '"Meeting"',
+          ],
+        ],
+        [
+          'Organization AS Contact_ActivityContact_Activity_01_Activity_Organization_Org_01',
+          'INNER',
+          [
+            'Contact_ActivityContact_Activity_01.Activity_fields.Org',
+            '=',
+            'Contact_ActivityContact_Activity_01_Activity_Organization_Org_01.id',
+          ],
+        ],
+      ],
+    ]);
+
+    $this->assertCount(1, $result);
+    $this->assertEquals($target['id'], $result[0]['id']);
+    $this->assertSame('Test Meeting', $result[0]['Contact_ActivityContact_Activity_01.subject']);
+    $this->assertSame('Test Organization', $result[0]['Contact_ActivityContact_Activity_01_Activity_Organization_Org_01.organization_name']);
+  }
+
 }