[10.x] Failing test/bug report in HasManyThrough updateOrCreate() since Laravel 10.21

tests/Integration/Database/EloquentHasManyThroughTest.php

@@ -139,6 +139,53 @@ public function testHasSameParentAndThroughParentTable()
 
         $this->assertEquals([1], $categories->pluck('id')->all());
     }
+
+    public function testUpdateOrCreateWillNotUseIdFromParentModel()
+    {
+        // On Laravel 10.21.0, a bug was introduced that would update the wrong model when using `updateOrCreate()`,
+        // because the UPDATE statement would target a model based on the ID from the parent instead of the actual
+        // conditions that the `updateOrCreate()` targeted. This test replicates the case that causes this bug.
+
+        // Manually provide IDs, keep ID 1 and 2 free for the team-mates.
+        $user1 = User::create(['name' => Str::random(), 'id' => 3]);
+        $user2 = User::create(['name' => Str::random(), 'id' => 4]);
+
+        $team1 = Team::create(['owner_id' => $user1->id]);
+        $team2 = Team::create(['owner_id' => $user2->id]);
+
+        $teamMate1 = User::create(['name' => 'John', 'slug' => 'john-slug', 'team_id' => $team1->id, 'id' => 2]);
+        // $teamMate2->id should be the same as the $team1->id for the bug to occur.
+        $teamMate2 = User::create(['name' => 'Jane', 'slug' => 'jane-slug', 'team_id' => $team2->id, 'id' => $team1->id]);
+
+        $this->assertSame(2, $teamMate1->id);
+        $this->assertSame(1, $teamMate2->id);
+
+        $this->assertSame(2, $teamMate1->refresh()->id);
+        $this->assertSame(1, $teamMate2->refresh()->id);
+
+        $this->assertSame('john-slug', $teamMate1->slug);
+        $this->assertSame('jane-slug', $teamMate2->slug);
+
+        $this->assertSame('john-slug', $teamMate1->refresh()->slug);
+        $this->assertSame('jane-slug', $teamMate2->refresh()->slug);
+
+        $user1->teamMates()->updateOrCreate([
+            'name' => 'John',
+            // The `updateOrCreate()` method tries to retrieve an existing model first like `->where($conditions)->first()`.
+            // In our case, that will return the model with the name `John`. However, the ID of the model with the name
+            // `John` is hydrated to `1` – where the actual ID should be `2` for the model with the name `John` (see
+            // the assertions above). If the `->where($conditions)->first()` return a model, a `->fill()->save()`
+            // action is executed. Because the ID is incorrectly hydrated to `1`, it will now update the Jane
+            // model with *all* the attributes of the `John` model, instead of updating the `John` model.
+        ], [
+            'slug' => 'john-doe',
+        ]);
+
+        // Expect $teamMate1's slug to be updated to john-doe instead of john-old.
+        $this->assertSame('john-doe', $teamMate1->fresh()->slug);
+        // $teamMate2 should not be updated, because it belongs to a different user altogether.
+        $this->assertSame('jane-slug', $teamMate2->fresh()->slug);
+    }
 }
 
 class User extends Model