Simplifiying the firstInFlowChildBox function

third_party/WebKit/Source/core/layout/LayoutBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 1560 matching lines @@
     next = next->nextSiblingBox();
   return next;
 }
 
 inline LayoutBox* LayoutBox::parentBox() const {
   return toLayoutBox(parent());
 }
 
 inline LayoutBox* LayoutBox::firstInFlowChildBox() const {
   LayoutBox* first = firstChildBox();
-  while (first && first->isOutOfFlowPositioned())
-    first = first->nextInFlowSiblingBox();
-  return first;
+  return !first->isOutOfFlowPositioned() ? first
+                                         : first->nextInFlowSiblingBox();

[Manuel Rego, 2016/10/19 11:49:55]

Don't you need to check if first is not null?
What happens if you call this in a box without children?

 }
 
 inline LayoutBox* LayoutBox::firstChildBox() const {
   return toLayoutBox(slowFirstChild());
 }
 
 inline LayoutBox* LayoutBox::lastChildBox() const {
   return toLayoutBox(slowLastChild());
 }
 
@@ skipping 27 matching lines @@
 
 inline bool LayoutBox::isForcedFragmentainerBreakValue(EBreak breakValue) {
   return breakValue == BreakColumn || breakValue == BreakLeft ||
          breakValue == BreakPage || breakValue == BreakRecto ||
          breakValue == BreakRight || breakValue == BreakVerso;
 }
 
 }  // namespace blink
 
 #endif  // LayoutBox_h