unify code duplication in ScInterpreter::ScSum and IterateParameters

The code in ScSum is mostly identical with that in IterateParameters.
Worse, functions like SUBTOTAL and AGGREGATE use IterateParameters for
the SUM function.
Now we have one set of code for all SUM-functions and averted the danger of
diverting pieces of code which are supposed to do the same thing.

Removed old-style bNull-method too.

Change-Id: Ia4f22c21c4b3c3a244ea1cd10c30d8cfcaa8ef6c
Reviewed-on: https://gerrit.libreoffice.org/15362Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>

sc/inc/columnspanset.hxx

@@ -84,6 +84,7 @@ public:
         virtual ~ColumnAction() = 0;
         virtual void startColumn(ScColumn* pCol) = 0;
         virtual void execute(SCROW nRow1, SCROW nRow2, bool bVal) = 0;
+        virtual void executeSum(SCROW, SCROW, bool, double& )  { return; } ;
     };
 
     ColumnSpanSet(bool bInit);
@@ -103,6 +104,7 @@ public:
 
     void executeAction(Action& ac) const;
     void executeColumnAction(ScDocument& rDoc, ColumnAction& ac) const;
+    void executeColumnAction(ScDocument& rDoc, ColumnAction& ac, double& fMem) const;
 
     void swap( ColumnSpanSet& r );
 };

sc/source/core/data/columnspanset.cxx

@@ -227,6 +227,49 @@ void ColumnSpanSet::executeColumnAction(ScDocument& rDoc, ColumnAction& ac) cons
     }
 }
 
+void ColumnSpanSet::executeColumnAction(ScDocument& rDoc, ColumnAction& ac, double& fMem) const
+{
+    for (size_t nTab = 0; nTab < maDoc.size(); ++nTab)
+    {
+        if (!maDoc[nTab])
+            continue;
+
+        const TableType& rTab = *maDoc[nTab];
+        for (size_t nCol = 0; nCol < rTab.size(); ++nCol)
+        {
+            if (!rTab[nCol])
+                continue;
+
+            ScTable* pTab = rDoc.FetchTable(nTab);
+            if (!pTab)
+                continue;
+
+            if (!ValidCol(nCol))
+            {
+                // End the loop.
+                nCol = rTab.size();
+                continue;
+            }
+
+            ScColumn& rColumn = pTab->aCol[nCol];
+            ac.startColumn(&rColumn);
+            ColumnType& rCol = *rTab[nCol];
+            ColumnSpansType::const_iterator it = rCol.maSpans.begin(), itEnd = rCol.maSpans.end();
+            SCROW nRow1, nRow2;
+            nRow1 = it->first;
+            bool bVal = it->second;
+            for (++it; it != itEnd; ++it)
+            {
+                nRow2 = it->first-1;
+                ac.executeSum( nRow1, nRow2, bVal, fMem );
+
+                nRow1 = nRow2+1; // for the next iteration.
+                bVal = it->second;
+            }
+        }
+    }
+}
+
 void ColumnSpanSet::swap( ColumnSpanSet& r )
 {
     maDoc.swap(r.maDoc);