From 3375c1f9be3aabf914cdb8254bdef994effc4deb Mon Sep 17 00:00:00 2001
From: Mike Dalessio <mike.dalessio@gmail.com>
Date: Tue, 6 Dec 2022 01:51:37 -0500
Subject: [PATCH] fix: XML::Reader#attribute_hash returns nil on error

This restores the behavior from v1.13.7
---
 ext/nokogiri/xml_reader.c |  4 ++++
 test/xml/test_reader.rb   | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/ext/nokogiri/xml_reader.c b/ext/nokogiri/xml_reader.c
index 022f8ff531..0895ea6a72 100644
--- a/ext/nokogiri/xml_reader.c
+++ b/ext/nokogiri/xml_reader.c
@@ -212,6 +212,10 @@ rb_xml_reader_attribute_hash(VALUE rb_reader)
   }
 
   c_node = xmlTextReaderExpand(c_reader);
+  if (c_node == NULL) {
+    return Qnil;
+  }
+
   c_property = c_node->properties;
   while (c_property != NULL) {
     VALUE rb_name = NOKOGIRI_STR_NEW2(c_property->name);
diff --git a/test/xml/test_reader.rb b/test/xml/test_reader.rb
index ab119656c7..c0813efc15 100644
--- a/test/xml/test_reader.rb
+++ b/test/xml/test_reader.rb
@@ -681,6 +681,30 @@ def test_nonexistent_attribute
         reader.read # el
         assert_nil(reader.attribute("other"))
       end
+
+      def test_broken_markup_attribute_hash
+        xml = <<~XML
+          <root><foo bar="asdf">
+        XML
+        reader = Nokogiri::XML::Reader(xml)
+        reader.read # root
+        reader.read # foo
+
+        assert_equal("foo", reader.name)
+        assert_nil(reader.attribute_hash)
+      end
+
+      def test_broken_markup_namespaces
+        xml = <<~XML
+          <root><foo bar="asdf">
+        XML
+        reader = Nokogiri::XML::Reader(xml)
+        reader.read # root
+        reader.read # foo
+
+        assert_equal("foo", reader.name)
+        assert_nil(reader.namespaces)
+      end
     end
   end
 end