state explicitly how ownership of ScFormulaCell::pCode works

Change-Id: I7c2938cd731ed85dd0f96ac41d0f0a1468ee858c
Reviewed-on: https://gerrit.libreoffice.org/69089
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

sc/inc/formulacell.hxx

@@ -128,7 +128,9 @@ private:
     SvNumFormatType nFormatType      : 16;
     ScFormulaResult aResult;
     formula::FormulaGrammar::Grammar  eTempGrammar;   // used between string (creation) and (re)compilation
-    ScTokenArray*   pCode;              // The (new) token array
+    // If this cell is in a cell group (mxGroup!=nullptr), then this pCode is a not-owning pointer
+    // to the mxGroup's mpCode, which owns the array. If the cell is not in a group, this is an owning pointer.
+    ScTokenArray*   pCode;              // The token array
     ScDocument*     pDocument;
     ScFormulaCell*  pPrevious;
     ScFormulaCell*  pNext;

sc/source/core/data/formulacell.cxx

@@ -1124,6 +1124,7 @@ void ScFormulaCell::Compile( const OUString& rFormula, bool bNoListening,
     ScTokenArray* pCodeOld = pCode;
     ScCompiler aComp( pDocument, aPos, eGrammar);
     pCode = aComp.CompileString( rFormula ).release();
+    assert(!mxGroup);
     delete pCodeOld;
     if( pCode->GetCodeError() == FormulaError::NONE )
     {
@@ -1158,6 +1159,7 @@ void ScFormulaCell::Compile(
     ScTokenArray* pCodeOld = pCode;
     ScCompiler aComp(rCxt, aPos);
     pCode = aComp.CompileString( rFormula ).release();
+    assert(!mxGroup);
     delete pCodeOld;
     if( pCode->GetCodeError() == FormulaError::NONE )
     {
@@ -1334,6 +1336,7 @@ void ScFormulaCell::CompileXML( sc::CompileFormulaContext& rCxt, ScProgress& rPr
     {
         ScTokenArray* pCodeOld = pCode;
         pCode = aComp.CompileString( aFormula, aFormulaNmsp ).release();
+        assert(!mxGroup);
         delete pCodeOld;
 
         if( pCode->GetCodeError() == FormulaError::NONE )