introduce ScCaptionPtr InUndo

Change-Id: Iccc2671b61f524244107233b77b56aaa45f5c72a

sc/inc/postit.hxx

@@ -85,6 +85,9 @@ public:
      */
     bool forget();
 
+    /** Flag that this instance is in Undo, so drawing layer owns it. */
+    void setInUndo();
+
     oslInterlockedCount getRefs() const;
 
 private:
@@ -101,6 +104,14 @@ private:
     Head*                 mpHead;       ///< points to the "master" entry
     mutable ScCaptionPtr* mpNext;       ///< next in list
     SdrCaptionObj*        mpCaption;    ///< the caption object, managed by head master
+    bool                  mbInUndo;     ///< whether this caption object is held in Undo
+                                            /* TODO: can that be moved to Head?
+                                             * It's unclear when to reset, so
+                                             * each instance has its own flag.
+                                             * The last reference count
+                                             * decrement automatically has the
+                                             * then current state available.
+                                             * */
 
     void newHead();             //< Allocate a new Head and init.
     void incRef() const;

sc/source/core/data/postit.cxx

@@ -445,12 +445,12 @@ ScNoteCaptionCreator::ScNoteCaptionCreator( ScDocument& rDoc, const ScAddress& r
 
 
 ScCaptionPtr::ScCaptionPtr() :
-    mpHead(nullptr), mpNext(nullptr), mpCaption(nullptr)
+    mpHead(nullptr), mpNext(nullptr), mpCaption(nullptr), mbInUndo(false)
 {
 }
 
 ScCaptionPtr::ScCaptionPtr( SdrCaptionObj* p ) :
-    mpHead(nullptr), mpNext(nullptr), mpCaption(p)
+    mpHead(nullptr), mpNext(nullptr), mpCaption(p), mbInUndo(false)
 {
     if (p)
     {
@@ -459,7 +459,7 @@ ScCaptionPtr::ScCaptionPtr( SdrCaptionObj* p ) :
 }
 
 ScCaptionPtr::ScCaptionPtr( const ScCaptionPtr& r ) :
-    mpHead(r.mpHead), mpCaption(r.mpCaption)
+    mpHead(r.mpHead), mpCaption(r.mpCaption), mbInUndo(false)
 {
     if (r.mpCaption)
     {
@@ -477,7 +477,7 @@ ScCaptionPtr::ScCaptionPtr( const ScCaptionPtr& r ) :
 }
 
 ScCaptionPtr::ScCaptionPtr( ScCaptionPtr&& r ) :
-    mpHead(r.mpHead), mpNext(r.mpNext), mpCaption(r.mpCaption)
+    mpHead(r.mpHead), mpNext(r.mpNext), mpCaption(r.mpCaption), mbInUndo(false)
 {
     r.replaceInList( this );
     r.mpCaption = nullptr;
@@ -534,6 +534,11 @@ ScCaptionPtr& ScCaptionPtr::operator=( const ScCaptionPtr& r )
     return *this;
 }
 
+void ScCaptionPtr::setInUndo()
+{
+    mbInUndo = true;
+}
+
 ScCaptionPtr::Head::Head( ScCaptionPtr* p ) :
     mpFirst(p), mnRefs(1)
 {