formula: Use appropriate OUString functions on string constants

Change-Id: I309d46f26a8c74b759add5c2d1edbbe37bc09365

formula/source/core/api/FormulaCompiler.cxx

@@ -1041,7 +1041,7 @@ bool FormulaCompiler::GetToken()
     if ( bAutoCorrect && !pStack )
     {   // don't merge stacked subroutine code into entered formula
         aCorrectedFormula += aCorrectedSymbol;
-        aCorrectedSymbol = "";
+        aCorrectedSymbol.clear();
     }
     bool bStop = false;
     if (pArr->GetCodeError() && mbStopOnError)
@@ -1423,7 +1423,7 @@ void FormulaCompiler::Factor()
             SetError( errParameterExpected );
             if ( bAutoCorrect && !pStack )
             {
-                aCorrectedSymbol = "";
+                aCorrectedSymbol.clear();
                 bCorrected = true;
             }
         }
@@ -1442,7 +1442,7 @@ void FormulaCompiler::Factor()
                     sal_Int32 nLen = aCorrectedFormula.getLength();
                     if ( nLen )
                         aCorrectedFormula = aCorrectedFormula.copy( 0, nLen - 1 );
-                    aCorrectedSymbol = "";
+                    aCorrectedSymbol.clear();
                     bCorrected = true;
                 }
             }
@@ -1649,8 +1649,8 @@ bool FormulaCompiler::CompileTokenArray()
     {
         if ( bAutoCorrect )
         {
-            aCorrectedFormula = "";
-            aCorrectedSymbol = "";
+            aCorrectedFormula.clear();
+            aCorrectedSymbol.clear();
         }
         pArr->nRefs = 0;    // count from start
         pArr->DelRPN();
@@ -1998,7 +1998,7 @@ OpCode FormulaCompiler::NextToken()
             {
                 if ( eOp == eLastOp || eLastOp == ocOpen )
                 {   // throw away duplicated operator
-                    aCorrectedSymbol = "";
+                    aCorrectedSymbol.clear();
                     bCorrected = true;
                 }
                 else
@@ -2136,7 +2136,7 @@ void FormulaCompiler::PushTokenArray( FormulaTokenArray* pa, bool bTemp )
     if ( bAutoCorrect && !pStack )
     {   // don't merge stacked subroutine code into entered formula
         aCorrectedFormula += aCorrectedSymbol;
-        aCorrectedSymbol = "";
+        aCorrectedSymbol.clear();
     }
     FormulaArrayStack* p = new FormulaArrayStack;
     p->pNext      = pStack;

formula/source/ui/dlg/FormulaHelper.cxx

@@ -274,7 +274,7 @@ sal_Int32 FormulaHelper::GetFunctionStart( const OUString&   rFormula,
         {
             nFStart = FUNC_NOTFOUND;
             if ( pFuncName )
-                (*pFuncName) = "";
+                pFuncName->clear();
         }
     }
     while(bRepeat);

formula/source/ui/dlg/formula.cxx

@@ -600,12 +600,12 @@ void FormulaDlg_Impl::UpdateValues()
     if ( CalcValue( pFuncDesc->getFormula( m_aArguments ), aStrResult ) )
         m_pWndResult->SetText( aStrResult );
 
-    aStrResult = "";
+    aStrResult.clear();
     if ( CalcValue(m_pHelper->getCurrentFormula(), aStrResult ) )
         m_pWndFormResult->SetText( aStrResult );
     else
     {
-        aStrResult = "";
+        aStrResult.clear();
         m_pWndFormResult->SetText( aStrResult );
     }
     CalcStruct(pMEdit->GetText());
@@ -780,7 +780,7 @@ void FormulaDlg_Impl::FillDialog(bool nFlag)
         m_pWndFormResult->SetText( aStrResult );
     else
     {
-        aStrResult = "";
+        aStrResult.clear();
         m_pWndFormResult->SetText( aStrResult );
     }
 }
@@ -1189,7 +1189,7 @@ void FormulaDlg_Impl::SaveArg( sal_uInt16 nEd )
 
         for(sal_uInt16 i=nClearPos; i<nArgs; i++)
         {
-            m_aArguments[i] = "";
+            m_aArguments[i].clear();
         }
     }
 }
@@ -1285,7 +1285,7 @@ IMPL_LINK_NOARG(FormulaDlg_Impl, FormulaHdl)
         m_pWndFormResult->SetText( aStrResult );
     else
     {
-        aStrResult = "";
+        aStrResult.clear();
         m_pWndFormResult->SetText( aStrResult );
     }
     CalcStruct(aString);
@@ -1478,7 +1478,7 @@ void FormulaDlg_Impl::Update()
 {
     FormEditData* pData = m_pHelper->getFormEditData();
     const OUString sExpression = pMEdit->GetText();
-    aOldFormula = "";
+    aOldFormula.clear();
     UpdateTokenArray(sExpression);
     FormulaCursorHdl(m_pMEFormula);
     CalcStruct(sExpression);
@@ -1897,7 +1897,7 @@ void FormEditData::Reset()
     aUniqueId=OString();
     aSelection.Min()=0;
     aSelection.Max()=0;
-    aUndoStr = "";
+    aUndoStr.clear();
 }
 
 const FormEditData& FormEditData::operator=( const FormEditData& r )