clone token in ScFormulaResult copy-ctor instead of referring

Replaces commit e2b11f4f

Prevent excessive references to single token instance during fill.

Because if not, we may run out of the 16-bit integer space to
store reference count.

sc/inc/formularesult.hxx

@@ -41,6 +41,20 @@ class ScFormulaResult
     static const Multiline MULTILINE_FALSE   = 1;
     static const Multiline MULTILINE_TRUE    = 2;
 
+    // Clone token if the 16-bit only reference counter is nearing it's
+    // capacity during fill or copy&paste, leaving 4k for temporary passing
+    // around. (That should be enough for all times (TM) ;-)
+    static const sal_uInt16 MAX_TOKENREF_COUNT = 0xf000;
+    static void IncrementTokenRef( const formula::FormulaToken* & rp )
+    {
+        if (rp)
+        {
+            if (rp->GetRef() >= MAX_TOKENREF_COUNT)
+                rp = rp->Clone();
+            rp->IncRef();
+        }
+    }
+
     union
     {
         double          mfValue;    // double result direct for performance and memory consumption
@@ -94,8 +108,12 @@ public:
                                             const ScMatrixFormulaCellToken* pMatFormula =
                                                 r.GetMatrixFormulaCellToken();
                                             if (pMatFormula)
+                                            {
                                                 mpToken = new ScMatrixFormulaCellToken( *pMatFormula);
-                                            mpToken->IncRef();
+                                                mpToken->IncRef();
+                                            }
+                                            else
+                                                IncrementTokenRef( mpToken);
                                         }
                                     }
                                     else
@@ -308,8 +326,7 @@ inline void ScFormulaResult::Assign( const ScFormulaResult & r )
 inline void ScFormulaResult::SetToken( const formula::FormulaToken* p )
 {
     ResetToDefaults();
-    if (p)
-        p->IncRef();
+    IncrementTokenRef( p);
     // Handle a result obtained from the interpreter to be assigned to a matrix
     // formula cell's ScMatrixFormulaCellToken.
     ScMatrixFormulaCellToken* pMatFormula = GetMatrixFormulaCellTokenNonConst();