Include a hash of the template content in the CMS Twig cache key

modules/cms/classes/CmsObject.php

@@ -306,7 +306,12 @@ public function getTwigContent()
      */
     public function getTwigCacheKey()
     {
-        $key = $this->getFilePath();
+        /*
+         * Twig names the compiled template class after this key and skips its freshness check once that class is
+         * loaded, so a long-running process (such as an Octane worker) would keep rendering the old version after
+         * an edit. Including a hash of the content gives each version its own class.
+         */
+        $key = $this->getFilePath() . '?' . hash('xxh128', (string) $this->getTwigContent());
 
         if ($event = $this->fireEvent('cmsObject.getTwigCacheKey', compact('key'), true)) {
             $key = $event;

modules/cms/classes/ComponentPartial.php

@@ -197,7 +197,12 @@ public function getTwigContent()
      */
     public function getTwigCacheKey()
     {
-        return $this->getFilePath();
+        /*
+         * Twig names the compiled template class after this key and skips its freshness check once that class is
+         * loaded, so a long-running process (such as an Octane worker) would keep rendering the old version after
+         * an edit. Including a hash of the content gives each version its own class.
+         */
+        return $this->getFilePath() . '?' . hash('xxh128', (string) $this->getTwigContent());
     }
 
     /**

modules/cms/tests/classes/CmsObjectTest.php

@@ -5,7 +5,11 @@
 use System\Tests\Bootstrap\TestCase;
 use Cms\Classes\CmsObject;
 use Cms\Classes\Theme;
+use Cms\Twig\Loader as TwigLoader;
 use PHPUnit\Framework\Attributes\Depends;
+use Twig\Cache\FilesystemCache as TwigCacheFilesystem;
+use Twig\Environment as TwigEnvironment;
+use Winter\Storm\Support\Facades\File;
 
 class TestCmsObject extends CmsObject
 {
@@ -335,4 +339,66 @@ public function testSaveNewDir()
         $this->assertFileExists($destFilePath);
         $this->assertEquals($testContents, file_get_contents($destFilePath));
     }
+
+    public function testEditedObjectRendersItsNewContentInTheSameProcess()
+    {
+        $theme = Theme::load('test');
+        $filePath = $theme->getPath() . '/temporary/twig-cache-key.htm';
+        $cachePath = storage_path('temp/twig-cache-key-test');
+        file_put_contents($filePath, '<p>Original.</p>');
+
+        try {
+            /*
+             * One Twig environment for the whole test, configured the way Cms\ServiceProvider configures it.
+             * A long-running process such as a queue worker or an Octane worker keeps the environment, and
+             * every compiled template class it has loaded, between requests.
+             */
+            $loader = new TwigLoader();
+            $twig = new TwigEnvironment($loader, [
+                'auto_reload' => true,
+                'cache' => new TwigCacheFilesystem($cachePath),
+            ]);
+
+            /*
+             * First request: compile and render the original content.
+             */
+            $obj = TestTemporaryCmsObject::load($theme, 'twig-cache-key.htm');
+            $loader->setObject($obj);
+            $this->assertSame('<p>Original.</p>', $twig->load($obj->getFilePath())->render([]));
+
+            /*
+             * An editor saves new content. The save lands in the same second as the first render, so the
+             * file's modification time may not change.
+             */
+            $obj->content = '<p>Edited.</p>';
+            $obj->save();
+            clearstatcache();
+
+            /*
+             * Next request: load the object from disk again and render it with the same environment. If the
+             * cache key were unchanged, Twig would reuse the class it already loaded and render the original.
+             */
+            CmsObject::clearInternalCache();
+            $obj = TestTemporaryCmsObject::load($theme, 'twig-cache-key.htm');
+            $loader->setObject($obj);
+            $this->assertSame('<p>Edited.</p>', $twig->load($obj->getFilePath())->render([]));
+        } finally {
+            @unlink($filePath);
+            File::deleteDirectory($cachePath);
+        }
+    }
+
+    public function testTwigCacheKeyCanBeOverriddenByEvent()
+    {
+        $theme = Theme::load('test');
+        $obj = TestCmsObject::load($theme, 'plain.html');
+
+        $this->assertStringStartsWith($obj->getFilePath() . '?', $obj->getTwigCacheKey());
+
+        $obj->bindEvent('cmsObject.getTwigCacheKey', function ($key) {
+            return 'custom-key';
+        });
+
+        $this->assertSame('custom-key', $obj->getTwigCacheKey());
+    }
 }