From 06f83d5c19ad0a98613830a2631a554009d256ba Mon Sep 17 00:00:00 2001
From: Coleman Watts <coleman@civicrm.org>
Date: Wed, 12 Aug 2020 11:44:39 -0400
Subject: [PATCH] Early return during APIv4::get if table doesn't exist

If there are pending upgrades, checks if table exists before attempting to read from it.
---
 CRM/Core/DAO.php                   | 17 +++++++++++++++++
 Civi/Api4/Generic/DAOGetAction.php |  6 ++++++
 tests/phpunit/CRM/Core/DAOTest.php | 13 +++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/CRM/Core/DAO.php b/CRM/Core/DAO.php
index 7c17558d88..96da596f6b 100644
--- a/CRM/Core/DAO.php
+++ b/CRM/Core/DAO.php
@@ -1148,6 +1148,23 @@ class CRM_Core_DAO extends DB_DataObject {
     return $result;
   }
 
+  /**
+   * Checks if this DAO's table ought to exist.
+   *
+   * If there are pending DB updates, this function compares the CiviCRM version of the table to the current schema version.
+   *
+   * @return bool
+   * @throws CRM_Core_Exception
+   */
+  public static function tableHasBeenAdded() {
+    if (CRM_Utils_System::version() === CRM_Core_BAO_Domain::version()) {
+      return TRUE;
+    }
+    $daoExt = constant(static::class . '::EXT');
+    $daoVersion = constant(static::class . '::TABLE_ADDED') ?? '1.0';
+    return !($daoExt === 'civicrm' && version_compare(CRM_Core_BAO_Domain::version(), $daoVersion, '<'));
+  }
+
   /**
    * Check if there is a given table in the database.
    *
diff --git a/Civi/Api4/Generic/DAOGetAction.php b/Civi/Api4/Generic/DAOGetAction.php
index 9ad1d54adc..cbdec8841e 100644
--- a/Civi/Api4/Generic/DAOGetAction.php
+++ b/Civi/Api4/Generic/DAOGetAction.php
@@ -85,6 +85,12 @@ class DAOGetAction extends AbstractGetAction {
   protected $having = [];
 
   public function _run(Result $result) {
+    // Early return if table doesn't exist yet due to pending upgrade
+    $baoName = $this->getBaoName();
+    if (!$baoName::tableHasBeenAdded()) {
+      return;
+    }
+
     $this->setDefaultWhereClause();
     $this->expandSelectClauseWildcards();
     $this->getObjects($result);
diff --git a/tests/phpunit/CRM/Core/DAOTest.php b/tests/phpunit/CRM/Core/DAOTest.php
index ed008287ed..0523aab7d5 100644
--- a/tests/phpunit/CRM/Core/DAOTest.php
+++ b/tests/phpunit/CRM/Core/DAOTest.php
@@ -542,4 +542,17 @@ class CRM_Core_DAOTest extends CiviUnitTestCase {
     $this->assertArrayNotHasKey('api_key', $permissionedContactFields);
   }
 
+  public function testTableHasBeenAdded() {
+    // Hack a different db version
+    CRM_Core_BAO_Domain::getDomain()->version = '5.28.0';
+
+    // Table was added in 5.29
+    $this->assertFalse(CRM_Contact_DAO_RelationshipCache::tableHasBeenAdded());
+
+    // Remove domain version override:
+    CRM_Core_BAO_Domain::version(TRUE);
+
+    $this->assertTrue(CRM_Contact_DAO_RelationshipCache::tableHasBeenAdded());
+  }
+
 }
-- 
2.25.1