From 970554f9b8910ef1a1999def91b5e8a129be6bc6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Thu, 6 Sep 2018 10:10:54 +0200
Subject: [PATCH] [poincare] Allow construction of a TreeRef from nullptr node

---
 poincare/include/poincare/layout_reference.h  | 10 ++++++++--
 poincare/include/poincare/tree_by_reference.h |  7 ++++---
 poincare/src/layout_node.cpp                  |  6 +-----
 poincare/src/layout_reference.cpp             |  6 ------
 4 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/poincare/include/poincare/layout_reference.h b/poincare/include/poincare/layout_reference.h
index 103b76c46..22161ec51 100644
--- a/poincare/include/poincare/layout_reference.h
+++ b/poincare/include/poincare/layout_reference.h
@@ -83,8 +83,14 @@ public:
     TreeByReference treeRefChild = TreeByReference::childAtIndex(i);
     return LayoutReference(static_cast<LayoutNode *>(treeRefChild.node()));
   }
-  LayoutReference root() const;
-  LayoutReference parent() const { return isUninitialized() ? LayoutReference() : LayoutReference(node()->parent()); }
+  LayoutReference root() const {
+    assert(!isUninitialized());
+    return LayoutReference(node()->root());
+  }
+  LayoutReference parent() const {
+    assert(!isUninitialized());
+    return LayoutReference(node()->parent());
+  }
 
   // Tree modification
   //Add
diff --git a/poincare/include/poincare/tree_by_reference.h b/poincare/include/poincare/tree_by_reference.h
index 9b3b59638..4a512d65c 100644
--- a/poincare/include/poincare/tree_by_reference.h
+++ b/poincare/include/poincare/tree_by_reference.h
@@ -88,9 +88,10 @@ public:
 
 protected:
   /* Constructor */
-  TreeByReference(const TreeNode * node) {
-    assert(node != nullptr);
-    setIdentifierAndRetain(node->identifier());
+  TreeByReference(const TreeNode * node) : TreeByReference() {
+    if (node != nullptr) {
+      setIdentifierAndRetain(node->identifier());
+    }
   }
   TreeByReference(int nodeIndentifier = TreePool::NoNodeIdentifier) : m_identifier(nodeIndentifier) {}
   void setIdentifierAndRetain(int newId) {
diff --git a/poincare/src/layout_node.cpp b/poincare/src/layout_node.cpp
index ee735f2a1..5d5dddcca 100644
--- a/poincare/src/layout_node.cpp
+++ b/poincare/src/layout_node.cpp
@@ -228,12 +228,8 @@ void LayoutNode::scoreCursorInDescendantsVertically (
 }
 
 bool LayoutNode::changeGreySquaresOfAllMatrixAncestors(bool add) {
-  LayoutNode * p = parent();
-  if (p == nullptr) {
-    return false;
-  }
   bool changedSquares = false;
-  LayoutRef currentAncestor = LayoutRef(p);
+  LayoutRef currentAncestor = LayoutRef(parent());
   while (!currentAncestor.isUninitialized()) {
     if (currentAncestor.isMatrix()) {
       if (add) {
diff --git a/poincare/src/layout_reference.cpp b/poincare/src/layout_reference.cpp
index 8292cf503..39a987473 100644
--- a/poincare/src/layout_reference.cpp
+++ b/poincare/src/layout_reference.cpp
@@ -19,12 +19,6 @@ LayoutCursor LayoutReference::equivalentCursor(LayoutCursor * cursor) {
   return node()->equivalentCursor(cursor);
 }
 
-LayoutReference LayoutReference::root() const {
-  assert(!isUninitialized());
-  LayoutNode * r = node()->root();
-  return r == nullptr ? LayoutReference() : LayoutReference(r);
-}
-
 // Tree modification
 
 void LayoutReference::replaceChild(LayoutRef oldChild, LayoutRef newChild, LayoutCursor * cursor, bool force) {