From d33332cb9e7aededfb73a3cbf362490ee1e77ca4 Mon Sep 17 00:00:00 2001
From: Guy Sartorelli <36352093+GuySartorelli@users.noreply.github.com>
Date: Thu, 15 Feb 2024 11:57:22 +1300
Subject: [PATCH] FIX Add eagerloaded data to ALL relevant lists (#11139)

---
 src/ORM/DataList.php                       |  2 +-
 src/ORM/EagerLoadedList.php                |  2 +-
 tests/php/ORM/DataListEagerLoadingTest.php | 35 ++++++++++++++++++++++
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/ORM/DataList.php b/src/ORM/DataList.php
index edc3c040cf9..c7cfc745dc9 100644
--- a/src/ORM/DataList.php
+++ b/src/ORM/DataList.php
@@ -1372,7 +1372,7 @@ private function addEagerLoadedDataToParent(
                 if ($parentData->hasID($parentID)) {
                     $parentData->addEagerLoadedData($relationName, $parentID, $eagerLoadedData);
                     $added = true;
-                    break;
+                    // can't break here, because the parent might be in multiple relation lists
                 }
             } else {
                 throw new LogicException("Invalid parent for eager loading $relationType relation $relationName");
diff --git a/src/ORM/EagerLoadedList.php b/src/ORM/EagerLoadedList.php
index 6464aea8018..902a1860843 100644
--- a/src/ORM/EagerLoadedList.php
+++ b/src/ORM/EagerLoadedList.php
@@ -940,7 +940,7 @@ private function setDataObjectEagerLoadedData(int $id, DataObject $item): void
 
     /**
      * Gets the final rows for this list after applying all transformations.
-     * Currently only limit is applied lazily, but others could be done this was as well.
+     * Currently only limit and sort are applied lazily, but filter could be done this was as well in the future.
      */
     private function getFinalisedRows(): array
     {
diff --git a/tests/php/ORM/DataListEagerLoadingTest.php b/tests/php/ORM/DataListEagerLoadingTest.php
index 2871ce834b7..b27bf050fac 100644
--- a/tests/php/ORM/DataListEagerLoadingTest.php
+++ b/tests/php/ORM/DataListEagerLoadingTest.php
@@ -1254,4 +1254,39 @@ public function testLastHasEagerloadedRelation()
         $obj = EagerLoadObject::get()->eagerLoad('HasManyEagerLoadObjects')->last();
         $this->assertInstanceOf(EagerLoadedList::class, $obj->HasManyEagerLoadObjects());
     }
+
+    /**
+     * Tests that if the same record exists in multiple relations, its data is
+     * eagerloaded without extra unnecessary queries.
+     */
+    public function testEagerLoadingSharedRelations()
+    {
+        $record1 = EagerLoadObject::create(['Title' => 'My obj1']);
+        $record1->write();
+        $record2 = EagerLoadObject::create(['Title' => 'My obj2']);
+        $record2->write();
+        $manyMany = ManyManyEagerLoadObject::create(['Title' => 'My manymany']);
+        $manyMany->write();
+        $record1->ManyManyEagerLoadObjects()->add($manyMany);
+        $record2->ManyManyEagerLoadObjects()->add($manyMany);
+        $subManyMany = ManyManySubEagerLoadObject::create(['Title' => 'My submanymany']);
+        $subManyMany->write();
+        $manyMany->ManyManySubEagerLoadObjects()->add($subManyMany);
+
+        $eagerLoadQuery = EagerLoadObject::get()
+            ->filter(['ID' => [$record1->ID, $record2->ID]])
+            ->eagerLoad('ManyManyEagerLoadObjects.ManyManySubEagerLoadObjects');
+        $loop1Count = 0;
+        $loop2Count = 0;
+        foreach ($eagerLoadQuery as $record) {
+            $loop1Count++;
+            $eagerLoaded1 = $record->ManyManyEagerLoadObjects();
+            $this->assertInstanceOf(EagerLoadedList::class, $eagerLoaded1);
+            foreach ($eagerLoaded1 as $manyManyRecord) {
+                $loop2Count++;
+                $eagerLoaded2 = $manyManyRecord->ManyManySubEagerLoadObjects();
+                $this->assertInstanceOf(EagerLoadedList::class, $eagerLoaded2);
+            }
+        }
+    }
 }