Fix LayoutObject::mapLocalToAncestor() for fixed under absolute

third_party/WebKit/Source/core/layout/MapCoordinatesTest.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
 #include "platform/geometry/TransformState.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 487 matching lines @@
   mappedPoint = mapAncestorToLocal(staticChild, container, mappedPoint);
   EXPECT_EQ(FloatPoint(-15, -15), mappedPoint);
 
   mappedPoint = mapAncestorToLocal(outerFixed, staticChild, mappedPoint);
   EXPECT_EQ(FloatPoint(-101, -101), mappedPoint);
 
   mappedPoint = mapAncestorToLocal(target, outerFixed, mappedPoint);
   EXPECT_EQ(FloatPoint(), mappedPoint);
 }
 
+TEST_F(MapCoordinatesTest, FixedPosInFixedPosScrollView) {
+  setBodyInnerHTML(
+      "<div style='height: 4000px'></div>"
+      "<div id='container' style='position:fixed; top: 100px; left: 100px'>"
+      "  <div id='target' style='position:fixed; top: 200px; left: 200px'>"
+      "  </div>"
+      "</div>");
+
+  LayoutBox* target = toLayoutBox(getLayoutObjectByElementId("target"));
+  LayoutBox* container = toLayoutBox(getLayoutObjectByElementId("container"));
+  LayoutBox* body = container->parentBox();
+  LayoutBox* html = body->parentBox();
+  LayoutBox* view = html->parentBox();
+  ASSERT_TRUE(view->isLayoutView());
+
+  document().view()->setScrollOffset(ScrollOffset(0.0, 50), ProgrammaticScroll);
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_EQ(50, document().view()->scrollOffsetInt().height());
+
+  FloatPoint mappedPoint = mapLocalToAncestor(target, view, FloatPoint());
+  EXPECT_EQ(FloatPoint(200, 250), mappedPoint);
+  mappedPoint = mapAncestorToLocal(target, view, FloatPoint(200, 250));
+  EXPECT_EQ(FloatPoint(), mappedPoint);
+
+  mappedPoint = mapLocalToAncestor(target, container, FloatPoint());
+  EXPECT_EQ(FloatPoint(100, 100), mappedPoint);
+  mappedPoint = mapAncestorToLocal(target, container, FloatPoint(100, 100));
+  EXPECT_EQ(FloatPoint(), mappedPoint);
+}
+
+TEST_F(MapCoordinatesTest, FixedPosInAbsolutePosScrollView) {
+  setBodyInnerHTML(
+      "<div style='height: 4000px'></div>"
+      "<div id='container' style='position:absolute; top: 100px; left: 100px'>"
+      "  <div id='target' style='position:fixed; top: 200px; left: 200px'>"
+      "  </div>"
+      "</div>");
+
+  LayoutBox* target = toLayoutBox(getLayoutObjectByElementId("target"));
+  LayoutBox* container = toLayoutBox(getLayoutObjectByElementId("container"));
+  LayoutBox* body = container->parentBox();
+  LayoutBox* html = body->parentBox();
+  LayoutBox* view = html->parentBox();
+  ASSERT_TRUE(view->isLayoutView());
+
+  document().view()->setScrollOffset(ScrollOffset(0.0, 50), ProgrammaticScroll);
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_EQ(50, document().view()->scrollOffsetInt().height());
+
+  FloatPoint mappedPoint = mapLocalToAncestor(target, view, FloatPoint());
+  EXPECT_EQ(FloatPoint(200, 250), mappedPoint);
+  mappedPoint = mapAncestorToLocal(target, view, FloatPoint(200, 250));
+  EXPECT_EQ(FloatPoint(), mappedPoint);
+
+  mappedPoint = mapLocalToAncestor(target, container, FloatPoint());
+  EXPECT_EQ(FloatPoint(100, 150), mappedPoint);
+  mappedPoint = mapAncestorToLocal(target, container, FloatPoint(100, 150));
+  EXPECT_EQ(FloatPoint(), mappedPoint);
+}
+
 TEST_F(MapCoordinatesTest, FixedPosInTransform) {
   setBodyInnerHTML(
       "<style>#container { transform: translateY(100px); position: absolute; "
       "left: 0; top: 100px; }"
       ".fixed { position: fixed; top: 0; }"
       ".spacer { height: 2000px; } </style>"
       "<div id='container'><div class='fixed' id='target'></div></div>"
       "<div class='spacer'></div>");
 
   document().view()->setScrollOffset(ScrollOffset(0.0, 50), ProgrammaticScroll);
@@ skipping 935 matching lines @@
               LayoutUnit::epsilon());
   EXPECT_NEAR(50.0, matrix.projectPoint(FloatPoint(100.0, 50.0)).y(),
               LayoutUnit::epsilon());
   EXPECT_NEAR(25.0, matrix.projectPoint(FloatPoint(50.0, 100.0)).x(),
               LayoutUnit::epsilon());
   EXPECT_NEAR(100.0, matrix.projectPoint(FloatPoint(50.0, 100.0)).y(),
               LayoutUnit::epsilon());
 }
 
 }  // namespace blink