[Editing] Add null check in |DeleteSelectionCommand::removeRedundantBlocks()|

third_party/WebKit/Source/core/editing/commands/ApplyStyleCommandTest.cpp

Index: third_party/WebKit/Source/core/editing/commands/ApplyStyleCommandTest.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/ApplyStyleCommandTest.cpp b/third_party/WebKit/Source/core/editing/commands/ApplyStyleCommandTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5357b8e35e2e444e785e6b943538fe652c855396
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/commands/ApplyStyleCommandTest.cpp
@@ -0,0 +1,51 @@
+// 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/editing/commands/ApplyStyleCommand.h"
+
+#include "core/css/StylePropertySet.h"
+#include "core/dom/Document.h"
+#include "core/editing/EditingTestBase.h"
+#include "core/editing/FrameSelection.h"
+#include "core/frame/LocalFrame.h"
+
+namespace blink {
+
+class ApplyStyleCommandTest : public EditingTestBase {};
+
+// This is a regression test for https://crbug.com/675727
+TEST_F(ApplyStyleCommandTest, RemoveRedundantBlocksWithStarEditableStyle) {
+  // The second <div> below is redundant from Blink's perspective (no siblings
+  // && no attributes) and will be removed by
+  // |DeleteSelectionCommand::removeRedundantBlocks()|.
+  setBodyContent(
+      "<div><div>"
+      "<div></div>"
+      "<ul>"
+      "<li>"
+      "<div></div>"
+      "<input>"
+      "<style> * {-webkit-user-modify: read-write;}</style><div></div>"
+      "</li>"
+      "</ul></div></div>");
+
+  Element* li = document().querySelector("li");
+
+  LocalFrame* frame = document().frame();
+  frame->selection().setSelection(
+      SelectionInDOMTree::Builder()
+          .collapse(Position(li, PositionAnchorType::BeforeAnchor))
+          .build());
+
+  MutableStylePropertySet* style =
+      MutableStylePropertySet::create(HTMLQuirksMode);
+  style->setProperty(CSSPropertyTextAlign, "center");
+  ApplyStyleCommand::create(document(), EditingStyle::create(style),
+                            InputEvent::InputType::FormatJustifyCenter,
+                            ApplyStyleCommand::ForceBlockProperties)
+      ->apply(EditCommandSource::kDOM);
+  // Shouldn't crash.
+}
+
+}  // namespace blink