never call shared_from_this on not fully init-ed object

Fixes regression since commit bbe7f806b95ef427153ba18bff80e674b1704ae5
"replace dumb pointers by smart ones".

Change-Id: Ie0dd277bc55347bb1ae5a59ccbeaffaa5ce6772a

3 files changed, 18 insertions, 26 deletions

diff --git a/src/lib/MSPUBCollector.cpp b/src/lib/MSPUBCollector.cpp
index 65e432c..718feba 100644
--- a/src/lib/MSPUBCollector.cpp
+++ b/src/lib/MSPUBCollector.cpp
@@ -439,7 +439,7 @@ void MSPUBCollector::setShapeClipPath(unsigned seqNum, const std::vector<Vertex>
 
 void MSPUBCollector::beginGroup()
 {
-  auto tmp = std::make_shared<ShapeGroupElement>(m_currentShapeGroup.get());
+  auto tmp = ShapeGroupElement::create(m_currentShapeGroup);
   if (!m_currentShapeGroup)
   {
     m_topLevelShapes.push_back(tmp);
@@ -455,7 +455,7 @@ bool MSPUBCollector::endGroup()
   }
   auto parent = m_currentShapeGroup->getParent();
   if (parent)
-    m_currentShapeGroup = parent->shared_from_this();
+    m_currentShapeGroup = parent;
   return true;
 }
 
@@ -497,7 +497,7 @@ bool MSPUBCollector::setCurrentGroupSeqNum(unsigned seqNum)
 
 void MSPUBCollector::setShapeOrder(unsigned seqNum)
 {
-  auto tmp = std::make_shared<ShapeGroupElement>(m_currentShapeGroup.get(), seqNum);
+  auto tmp = ShapeGroupElement::create(m_currentShapeGroup, seqNum);
   if (!m_currentShapeGroup)
   {
     m_topLevelShapes.push_back(tmp);
diff --git a/src/lib/ShapeGroupElement.cpp b/src/lib/ShapeGroupElement.cpp
index c61d412..6dcead8 100644
--- a/src/lib/ShapeGroupElement.cpp
+++ b/src/lib/ShapeGroupElement.cpp
@@ -12,24 +12,20 @@
 namespace libmspub
 {
 
-ShapeGroupElement::ShapeGroupElement(ShapeGroupElement *parent) : m_shapeInfo(), m_parent(parent), m_children(), m_seqNum(0), m_transform()
+ShapeGroupElement::ShapeGroupElement(const std::shared_ptr<ShapeGroupElement> &parent, unsigned seqNum) : m_shapeInfo(), m_parent(parent), m_children(), m_seqNum(seqNum), m_transform()
 {
-  if (m_parent)
-  {
-    m_parent->m_children.push_back(shared_from_this());
-  }
 }
 
 ShapeGroupElement::~ShapeGroupElement()
 {
 }
 
-ShapeGroupElement::ShapeGroupElement(ShapeGroupElement *parent, unsigned seqNum) : m_shapeInfo(), m_parent(parent), m_children(), m_seqNum(seqNum), m_transform()
+std::shared_ptr<ShapeGroupElement> ShapeGroupElement::create(const std::shared_ptr<ShapeGroupElement> &parent, unsigned seqNum)
 {
-  if (m_parent)
-  {
-    m_parent->m_children.push_back(shared_from_this());
-  }
+  auto that = std::shared_ptr<ShapeGroupElement>(new ShapeGroupElement(parent, seqNum));
+  if (parent)
+    parent->m_children.push_back(that);
+  return that;
 }
 
 void ShapeGroupElement::setShapeInfo(const ShapeInfo &shapeInfo)
@@ -89,14 +85,9 @@ bool ShapeGroupElement::isGroup() const
   return !m_children.empty();
 }
 
-ShapeGroupElement *ShapeGroupElement::getParent()
-{
-  return m_parent;
-}
-
-const ShapeGroupElement *ShapeGroupElement::getParent() const
+std::shared_ptr<ShapeGroupElement> ShapeGroupElement::getParent() const
 {
-  return m_parent;
+  return m_parent.lock();
 }
 
 void ShapeGroupElement::setSeqNum(unsigned seqNum)
diff --git a/src/lib/ShapeGroupElement.h b/src/lib/ShapeGroupElement.h
index ef7d175..a51fedc 100644
--- a/src/lib/ShapeGroupElement.h
+++ b/src/lib/ShapeGroupElement.h
@@ -19,19 +19,21 @@
 
 namespace libmspub
 {
-class ShapeGroupElement : public std::enable_shared_from_this<ShapeGroupElement>
+class ShapeGroupElement
 {
   boost::optional<ShapeInfo> m_shapeInfo;
-  ShapeGroupElement *m_parent;
+  std::weak_ptr<ShapeGroupElement> m_parent;
   std::vector<std::shared_ptr<ShapeGroupElement>> m_children;
   unsigned m_seqNum;
   ShapeGroupElement &operator=(const ShapeGroupElement &); //not implemented
   ShapeGroupElement(const ShapeGroupElement &); //not implemented
   VectorTransformation2D m_transform;
+  ShapeGroupElement(const std::shared_ptr<ShapeGroupElement> &parent, unsigned seqNum);
+
 public:
-  ShapeGroupElement(ShapeGroupElement *parent);
-  ShapeGroupElement(ShapeGroupElement *parent, unsigned seqNum);
   ~ShapeGroupElement();
+  static std::shared_ptr<ShapeGroupElement> create(const std::shared_ptr<ShapeGroupElement> &parent, unsigned seqNum = 0);
+
   void setShapeInfo(const ShapeInfo &shapeInfo);
   void setup(std::function<void(ShapeGroupElement &self)> visitor);
   void visit(std::function<
@@ -42,8 +44,7 @@ public:
              std::function<void(void)>
              (const ShapeInfo &info, const Coordinate &relativeTo, const VectorTransformation2D &foldedTransform, bool isGroup, const VectorTransformation2D &thisTransform)> visitor) const;
   bool isGroup() const;
-  ShapeGroupElement *getParent();
-  const ShapeGroupElement *getParent() const;
+  std::shared_ptr<ShapeGroupElement> getParent() const;
   void setSeqNum(unsigned seqNum);
   void setTransform(const VectorTransformation2D &transform);
   unsigned getSeqNum() const;