From 53b7810cf93cbe457cd48e25ff839a96f455123c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Tamarelle?= <jerome@tamarelle.net>
Date: Thu, 22 Jun 2023 19:59:50 +0200
Subject: [PATCH] PHPLIB-1167: Fix CachingIterator::count on empty Cursor

Fix error: Cannot advance a completed or failed cursor.
---
 src/Model/CachingIterator.php                 |  4 +-
 tests/Model/CachingIteratorFunctionalTest.php | 49 +++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 tests/Model/CachingIteratorFunctionalTest.php

diff --git a/src/Model/CachingIterator.php b/src/Model/CachingIterator.php
index d1ad098d4..ff0e35d55 100644
--- a/src/Model/CachingIterator.php
+++ b/src/Model/CachingIterator.php
@@ -110,8 +110,6 @@ public function next(): void
             $this->iterator->next();
 
             $this->storeCurrentItem();
-
-            $this->iteratorExhausted = ! $this->iterator->valid();
         }
 
         next($this->items);
@@ -152,6 +150,8 @@ private function exhaustIterator(): void
     private function storeCurrentItem(): void
     {
         if (! $this->iterator->valid()) {
+            $this->iteratorExhausted = true;
+
             return;
         }
 
diff --git a/tests/Model/CachingIteratorFunctionalTest.php b/tests/Model/CachingIteratorFunctionalTest.php
new file mode 100644
index 000000000..3d3ed002c
--- /dev/null
+++ b/tests/Model/CachingIteratorFunctionalTest.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace MongoDB\Tests\Model;
+
+use MongoDB\Model\CachingIterator;
+use MongoDB\Tests\FunctionalTestCase;
+
+class CachingIteratorFunctionalTest extends FunctionalTestCase
+{
+    /** @see https://jira.mongodb.org/browse/PHPLIB-1167 */
+    public function testEmptyCursor(): void
+    {
+        $collection = $this->dropCollection($this->getDatabaseName(), $this->getCollectionName());
+        $cursor = $collection->find();
+        $iterator = new CachingIterator($cursor);
+
+        $this->assertSame(0, $iterator->count());
+        $iterator->rewind();
+        $this->assertFalse($iterator->valid());
+        $this->assertFalse($iterator->current());
+        $this->assertNull($iterator->key());
+    }
+
+    public function testCursor(): void
+    {
+        $collection = $this->dropCollection($this->getDatabaseName(), $this->getCollectionName());
+        $collection->insertOne(['_id' => 1]);
+        $collection->insertOne(['_id' => 2]);
+        $cursor = $collection->find();
+        $iterator = new CachingIterator($cursor);
+
+        $this->assertSame(2, $iterator->count());
+
+        $iterator->rewind();
+        $this->assertTrue($iterator->valid());
+        $this->assertNotNull($iterator->current());
+        $this->assertSame(0, $iterator->key());
+
+        $iterator->next();
+        $this->assertTrue($iterator->valid());
+        $this->assertNotNull($iterator->current());
+        $this->assertSame(1, $iterator->key());
+
+        $iterator->next();
+        $this->assertFalse($iterator->valid());
+        $this->assertFalse($iterator->current());
+        $this->assertNull($iterator->key());
+    }
+}