From a69346521a6eec63fab84fe2a65b4900ae32b5d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Guillaume=20Delr=C3=A9?= <delre.guillaume@gmail.com>
Date: Mon, 11 May 2026 00:11:21 +0200
Subject: [PATCH] fix: skip DOMDocumentType when importing XML with DOCTYPE
 declaration
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DOMDocument::importNode() returns false for DOMDocumentType nodes,
causing appendChild() to receive a boolean and throw a fatal error.

This happens when loading or inserting XML that contains a <!DOCTYPE>
declaration: the node list from childNodes includes the DOMDocumentType
node alongside the root element.

Skip DOMDocumentType entries in attachNodes() before attempting the
import, so the document content is imported correctly and the DOCTYPE
declaration is silently discarded.

Fixes #44
Fixes #50

Signed-off-by: Guillaume Delré <delre.guillaume@gmail.com>
---
 source/FluidXml/FluidInsertionHandler.php |  5 ++++
 specs/FluidXml.php                        | 28 +++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/source/FluidXml/FluidInsertionHandler.php b/source/FluidXml/FluidInsertionHandler.php
index f47fd46..1c0e695 100644
--- a/source/FluidXml/FluidInsertionHandler.php
+++ b/source/FluidXml/FluidInsertionHandler.php
@@ -226,6 +226,11 @@ protected function attachNodes($parent, $nodes, $fn): array
                 $context = [];
 
                 foreach ($nodes as $el) {
+                        // DOMDocumentType cannot be imported as a child node.
+                        if ($el instanceof \DOMDocumentType) {
+                                continue;
+                        }
+
                         $el        = $this->dom->importNode($el, true);
                         $context[] = $fn($parent, $el);
                 }
diff --git a/specs/FluidXml.php b/specs/FluidXml.php
index 6cac1ef..5132f19 100644
--- a/specs/FluidXml.php
+++ b/specs/FluidXml.php
@@ -142,6 +142,34 @@
 
                         assert_is_a($actual, \Exception::class);
                 });
+
+                it('should import an XML file containing a DOCTYPE declaration', function () {
+                        $file = "{$this->out_dir}.test_load_doctype.xml";
+                        $doc  = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+                              . "<!DOCTYPE fcpxml>\n"
+                              . "<fcpxml version=\"1.8\"><resources/></fcpxml>";
+
+                        \file_put_contents($file, $doc);
+                        $xml = FluidXml::load($file);
+                        \unlink($file);
+
+                        $expected = "<fcpxml version=\"1.8\">\n  <resources/>\n</fcpxml>";
+                        assert_equal_xml($xml, $expected);
+                });
+        });
+
+        describe('.addChild() with DOCTYPE', function () {
+                it('should not throw when adding an XML string with a DOCTYPE declaration', function () {
+                        $xml    = new FluidXml(null);
+                        $xmlStr = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+                                . "<!DOCTYPE fcpxml>\n"
+                                . "<fcpxml version=\"1.8\"><resources/></fcpxml>";
+
+                        $xml->addChild($xmlStr);
+
+                        $expected = "<fcpxml version=\"1.8\">\n  <resources/>\n</fcpxml>";
+                        assert_equal_xml($xml, $expected);
+                });
         });
 
         if (\version_compare(\phpversion(), '7', '>=')) {