Unwind this logic and make it easier to read.

Change-Id: Iaf4ccc8949fb823a7bd3329c0164443220573b03

sc/inc/chgtrack.hxx

@@ -1013,6 +1013,8 @@ class ScChangeTrack : public utl::ConfigurationListener
                                 // bRecursion == called from reject with table
     bool Reject( ScChangeAction*, ScChangeActionMap*, bool bRecursion );
 
+    bool IsLastAction( sal_uLong nNum ) const;
+
             void                ClearMsgQueue();
     virtual void                ConfigurationChanged( utl::ConfigurationBroadcaster*, sal_uInt32 ) SAL_OVERRIDE;
 

sc/source/core/tool/chgtrack.cxx

@@ -3161,8 +3161,8 @@ void ScChangeTrack::Undo( sal_uLong nStartAction, sal_uLong nEndAction, bool bMe
         for ( sal_uLong j = nEndAction; j >= nStartAction; --j )
         {   // Traverse backwards to recycle nActionMax and for faster access via pLast
             // Deletes are in right order
-            ScChangeAction* pAct = ( (j == nActionMax && pLast &&
-                pLast->GetActionNumber() == j) ? pLast : GetAction( j ) );
+            ScChangeAction* pAct = IsLastAction(j) ? pLast : GetAction(j);
+
             if ( pAct )
             {
                 if ( pAct->IsDeleteType() )
@@ -4409,6 +4409,11 @@ bool ScChangeTrack::Reject(
     return bRejected;
 }
 
+bool ScChangeTrack::IsLastAction( sal_uLong nNum ) const
+{
+    return nNum == nActionMax && pLast && pLast->GetActionNumber() == nNum;
+}
+
 sal_uLong ScChangeTrack::AddLoadedGenerated(
     const ScCellValue& rNewCell, const ScBigRange& aBigRange, const OUString& sNewValue )
 {