XPath: Apply ignore-case matching to attribute names

... if attribute's owner element is an HTML element and its owner document
is an HTML document and it has no namespaceURI.

The new behavior matches to Firefox.

Bug: 179453
Change-Id: I499f809c8ad2620da2ef2c78fe6d301feec6f67b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1975494Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726562}

third_party/blink/renderer/core/xml/xpath_step.cc

@@ -192,6 +192,11 @@ static inline bool NodeMatchesBasicTest(Node* node,
           return namespace_uri.IsEmpty() ||
                  attr->namespaceURI() == namespace_uri;
 
+        if (attr->GetDocument().IsHTMLDocument() && attr->ownerElement() &&
+            attr->ownerElement()->IsHTMLElement() && namespace_uri.IsNull() &&
+            attr->namespaceURI().IsNull())
+          return EqualIgnoringASCIICase(attr->localName(), name);
+
         return attr->localName() == name &&
                attr->namespaceURI() == namespace_uri;
       }
@@ -385,8 +390,15 @@ void Step::NodesInAxis(EvaluationContext& evaluation_context,
       // need anyway.
       if (GetNodeTest().GetKind() == NodeTest::kNameTest &&
           GetNodeTest().Data() != g_star_atom) {
-        Attr* attr = context_element->getAttributeNodeNS(
-            GetNodeTest().NamespaceURI(), GetNodeTest().Data());
+        Attr* attr;
+        // We need this branch because getAttributeNodeNS() doesn't do
+        // ignore-case matching even for an HTML element in an HTML document.
+        if (GetNodeTest().NamespaceURI().IsNull()) {
+          attr = context_element->getAttributeNode(GetNodeTest().Data());
+        } else {
+          attr = context_element->getAttributeNodeNS(
+              GetNodeTest().NamespaceURI(), GetNodeTest().Data());
+        }
         // In XPath land, namespace nodes are not accessible on the attribute
         // axis.
         if (attr && attr->namespaceURI() != xmlns_names::kNamespaceURI) {

third_party/blink/web_tests/external/wpt/domxpath/002-expected.txt

-This is a testharness.js-based test.
-PASS Select html element based on attribute
-FAIL Select html element based on attribute mixed case assert_array_equals: lengths differ, expected 1 got 0
-PASS Select both HTML and SVG elements based on attribute
-PASS Select HTML element with non-ascii attribute 1
-PASS Select HTML element with non-ascii attribute 2
-FAIL Select HTML element with non-ascii attribute 3 assert_array_equals: lengths differ, expected 1 got 0
-PASS Select SVG element based on mixed case attribute
-FAIL Select both HTML and SVG elements based on mixed case attribute assert_array_equals: lengths differ, expected 1 got 0
-PASS Select SVG elements with refX attribute
-PASS Select SVG elements with refX attribute incorrect case
-PASS Select SVG elements with refX attribute lowercase
-PASS Select SVG element with non-ascii attribute 1
-PASS Select SVG element with non-ascii attribute 2
-PASS xmlns attribute
-PASS svg element with XLink attribute
-Harness: the test ran to completion.
-