From 7ea218aa1cb635434f939ba033abcf711f871665 Mon Sep 17 00:00:00 2001
From: Steve Boyd <emteknetnz@gmail.com>
Date: Wed, 16 Jan 2019 16:24:45 +1300
Subject: [PATCH 1/2] Ensure document is not falsey before attempting to clone
 it

---
 src/View/Parsers/HTMLValue.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/View/Parsers/HTMLValue.php b/src/View/Parsers/HTMLValue.php
index d41ef3708..aa6a3f535 100644
--- a/src/View/Parsers/HTMLValue.php
+++ b/src/View/Parsers/HTMLValue.php
@@ -35,7 +35,11 @@ abstract class HTMLValue extends ViewableData
      */
     public function getContent()
     {
-        $doc = clone $this->getDocument();
+        $document = $this->getDocument();
+        if (!$document) {
+            return '';
+        }
+        $doc = clone $document;
         $xp = new DOMXPath($doc);
 
         // If there's no body, the content is empty string

From d28552915d816036cf1bc80642776e58744f44a4 Mon Sep 17 00:00:00 2001
From: Steve Boyd <emteknetnz@gmail.com>
Date: Fri, 25 Jan 2019 15:55:03 +1300
Subject: [PATCH 2/2] Add unit test for an invalid HTMLValue

---
 tests/php/View/Parsers/HTML4ValueTest.php | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/tests/php/View/Parsers/HTML4ValueTest.php b/tests/php/View/Parsers/HTML4ValueTest.php
index 5e6f9ed28..018f7b08d 100644
--- a/tests/php/View/Parsers/HTML4ValueTest.php
+++ b/tests/php/View/Parsers/HTML4ValueTest.php
@@ -80,4 +80,19 @@ class HTML4ValueTest extends SapphireTest
         $value->setContent('<a href="&quot;"></a>');
         $this->assertEquals('<a href="&quot;"></a>', $value->getContent(), "'\"' character is escaped");
     }
+
+    public function testGetContent()
+    {
+        $value = new HTML4Value();
+
+        $value->setContent('<p>This is valid</p>');
+        $this->assertEquals('<p>This is valid</p>', $value->getContent(), "Valid content is returned");
+
+        $value->setContent('<p?< This is not really valid but it will get parsed into something valid');
+        // can sometimes get a this state where HTMLValue->valid is false
+        // for instance if a content editor saves something really weird in a LiteralField
+        // we can manually get to this state via ->setInvalid()
+        $value->setInvalid();
+        $this->assertEquals('', $value->getContent(), "Blank string is returned when invalid");
+    }
 }