Make Range::intersectsNode() to follow the spec

This patch change |Range::intersectsNode()| to follow the spec[1].

[1] https://dom.spec.whatwg.org/#dom-range-intersectsnode

Bug: 822510
Change-Id: Ifd504443355da12482b759701cddd62e2a90d7a6
Reviewed-on: https://chromium-review.googlesource.com/970044Reviewed-by: Kent Tamura <tkent@chromium.org>
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544971}

third_party/WebKit/LayoutTests/external/wpt/dom/ranges/Range-intersectsNode-2.html

+<!doctype htlml>
+<title>Range.intersectsNode</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="div"><span id="s0">s0</span><span id="s1">s1</span><span id="s2">s2</span></div>
+<script>
+// Taken from Chromium bug: http://crbug.com/822510
+test(() => {
+  const range = new Range();
+  const div = document.getElementById('div');
+  const s0 = document.getElementById('s0');
+  const s1 = document.getElementById('s1');
+  const s2 = document.getElementById('s2');
+
+  // Range encloses s0
+  range.setStart(div, 0);
+  range.setEnd(div, 1);
+  assert_true(range.intersectsNode(s0), '[s0] range.intersectsNode(s0)');
+  assert_false(range.intersectsNode(s1), '[s0] range.intersectsNode(s1)');
+  assert_false(range.intersectsNode(s2), '[s0] range.intersectsNode(s2)');
+
+  // Range encloses s1
+  range.setStart(div, 1);
+  range.setEnd(div, 2);
+  assert_false(range.intersectsNode(s0), '[s1] range.intersectsNode(s0)');
+  assert_true(range.intersectsNode(s1), '[s1] range.intersectsNode(s1)');
+  assert_false(range.intersectsNode(s2), '[s1] range.intersectsNode(s2)');
+
+  // Range encloses s2
+  range.setStart(div, 2);
+  range.setEnd(div, 3);
+  assert_false(range.intersectsNode(s0), '[s2] range.intersectsNode(s0)');
+  assert_false(range.intersectsNode(s1), '[s2] range.intersectsNode(s1)');
+  assert_true(range.intersectsNode(s2), '[s2] range.intersectsNode(s2)');
+}, 'Range.intersectsNode() simple cases');
+</script>

third_party/WebKit/Source/core/dom/Range.cpp

@@ -461,22 +461,8 @@ bool Range::intersectsNode(Node* ref_node, ExceptionState& exception_state) {
     return true;
 
   int node_index = ref_node->NodeIndex();
-
-  if (comparePoint(parent_node, node_index, exception_state) <
-          0  // starts before start
-      && comparePoint(parent_node, node_index + 1, exception_state) <
-             0) {  // ends before start
-    return false;
-  }
-
-  if (comparePoint(parent_node, node_index, exception_state) >
-          0  // starts after end
-      && comparePoint(parent_node, node_index + 1, exception_state) >
-             0) {  // ends after end
-    return false;
-  }
-
-  return true;  // all other cases
+  return Position(parent_node, node_index) < end_.ToPosition() &&
+         Position(parent_node, node_index + 1) > start_.ToPosition();
 }
 
 static inline Node* HighestAncestorUnderCommonRoot(Node* node,

third_party/WebKit/Source/core/dom/RangeTest.cpp

@@ -62,6 +62,42 @@ TEST_F(RangeTest, extractContentsWithDOMMutationEvent) {
       << "DOM mutation event handler should be executed.";
 }
 
+// http://crbug.com/822510
+TEST_F(RangeTest, IntersectsNode) {
+  SetBodyContent(
+      "<div>"
+      "<span id='s0'>s0</span>"
+      "<span id='s1'>s1</span>"
+      "<span id='s2'>s2</span>"
+      "</div>");
+  Element* const div = GetDocument().QuerySelector("div");
+  Element* const s0 = GetDocument().getElementById("s0");
+  Element* const s1 = GetDocument().getElementById("s1");
+  Element* const s2 = GetDocument().getElementById("s2");
+  Range& range = *Range::Create(GetDocument());
+
+  // Range encloses s0
+  range.setStart(div, 0);
+  range.setEnd(div, 1);
+  EXPECT_TRUE(range.intersectsNode(s0, ASSERT_NO_EXCEPTION));
+  EXPECT_FALSE(range.intersectsNode(s1, ASSERT_NO_EXCEPTION));
+  EXPECT_FALSE(range.intersectsNode(s2, ASSERT_NO_EXCEPTION));
+
+  // Range encloses s1
+  range.setStart(div, 1);
+  range.setEnd(div, 2);
+  EXPECT_FALSE(range.intersectsNode(s0, ASSERT_NO_EXCEPTION));
+  EXPECT_TRUE(range.intersectsNode(s1, ASSERT_NO_EXCEPTION));
+  EXPECT_FALSE(range.intersectsNode(s2, ASSERT_NO_EXCEPTION));
+
+  // Range encloses s2
+  range.setStart(div, 2);
+  range.setEnd(div, 3);
+  EXPECT_FALSE(range.intersectsNode(s0, ASSERT_NO_EXCEPTION));
+  EXPECT_FALSE(range.intersectsNode(s1, ASSERT_NO_EXCEPTION));
+  EXPECT_TRUE(range.intersectsNode(s2, ASSERT_NO_EXCEPTION));
+}
+
 TEST_F(RangeTest, SplitTextNodeRangeWithinText) {
   V8TestingScope scope;