From d2a32e3c8048de6e6c0d68f53d39d0c75b8a602a Mon Sep 17 00:00:00 2001
From: Martijn van der Ven <martijn@vanderven.se>
Date: Sun, 27 May 2018 12:10:35 +0200
Subject: [PATCH 1/2] Add failing test for mutating DOMDocument

A DOMDocument instance being passed to the parser should not have
changed after parsing. This could potentially trip-up further use of
the same DOMDocument instance.

See https://github.com/indieweb/php-mf2/issues/174.
---
 tests/Mf2/ParserTest.php | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/Mf2/ParserTest.php b/tests/Mf2/ParserTest.php
index c8bb68a..9bc4aae 100644
--- a/tests/Mf2/ParserTest.php
+++ b/tests/Mf2/ParserTest.php
@@ -790,5 +790,27 @@ public function testHtml5OptionalPEndTag() {
 		$this->assertEquals('Name', $output['items'][0]['properties']['name'][0]);
 	}
 
+	/**
+	 * Make sure the parser does not mutate any DOMDocument instances passed to the constructor.
+	 * @see https://github.com/indieweb/php-mf2/issues/174
+	 * @see https://github.com/microformats/mf2py/issues/104
+	 */
+	public function testNotMutatingPassedInDOM() {
+		$input = file_get_contents(__DIR__ . '/snarfed.org.html');
+
+		// Use same parsing as Parser::__construct(), twice to have a comparison object.
+		libxml_use_internal_errors(true);
+		$refDoc = new \DOMDocument();
+		@$refDoc->loadHTML(Mf2\unicodeToHtmlEntities($input));
+		$inputDoc = new \DOMDocument();
+		@$inputDoc->loadHTML(Mf2\unicodeToHtmlEntities($input));
+
+		// For completion sake, test PHP itself.
+		$this->assertEquals($refDoc, $inputDoc, 'PHP could not create identical DOMDocument instances.');
+
+		// Parse one DOMDocument instance, and test if it is still the same as the other.
+		Mf2\parse($inputDoc, 'http://snarfed.org/2013-10-23_oauth-dropins');
+		$this->assertEquals($refDoc, $inputDoc, 'Parsing mutated the DOMDocument.');
+	}
 }
 

From ffa5b67e30d9df8df69122931cab077694e72c61 Mon Sep 17 00:00:00 2001
From: Martijn van der Ven <martijn@vanderven.se>
Date: Sun, 27 May 2018 12:15:04 +0200
Subject: [PATCH 2/2] Fix #174 by cloning input DOMDocument instance

---
 Mf2/Parser.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Mf2/Parser.php b/Mf2/Parser.php
index 166efd3..b36555f 100644
--- a/Mf2/Parser.php
+++ b/Mf2/Parser.php
@@ -345,7 +345,7 @@ public function __construct($input, $url = null, $jsonMode = false) {
 				@$doc->loadHTML(unicodeToHtmlEntities($input));
 			}
 		} elseif (is_a($input, 'DOMDocument')) {
-			$doc = $input;
+			$doc = clone $input;
 		} else {
 			$doc = new DOMDocument();
 			@$doc->loadHTML('');