more robust implicit intersection optimizing

For example, FormulaCompiler::MergeRangeReference() may replace
the parameter tokens and merge two into one.

Change-Id: Ie2933dec3ef73b5b605160e86a8ab3b5b1d17c1c
Reviewed-on: https://gerrit.libreoffice.org/58684
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

sc/inc/compiler.hxx

@@ -305,10 +305,11 @@ private:
     // be important. Store candidate parameters and the operation they are the argument for.
     struct PendingImplicitIntersectionOptimization
     {
-        PendingImplicitIntersectionOptimization(formula::FormulaToken** p, const formula::FormulaToken* o)
-            : parameter( p ), operation( o ) {}
-        formula::FormulaToken** parameter;
-        const formula::FormulaToken* operation;
+        PendingImplicitIntersectionOptimization(formula::FormulaToken** p, formula::FormulaToken* o)
+            : parameterLocation( p ), parameter( *p ), operation( o ) {}
+        formula::FormulaToken** parameterLocation;
+        formula::FormulaTokenRef parameter;
+        formula::FormulaTokenRef operation;
     };
     std::vector< PendingImplicitIntersectionOptimization > mPendingImplicitIntersectionOptimizations;
     std::set<formula::FormulaTokenRef> mUnhandledPossibleImplicitIntersections;

sc/source/core/tool/compiler.cxx

@@ -5971,10 +5971,14 @@ void ScCompiler::PostProcessCode()
 {
     for( const PendingImplicitIntersectionOptimization& item : mPendingImplicitIntersectionOptimizations )
     {
+        if( *item.parameterLocation != item.parameter ) // the parameter has been changed somehow
+            continue;
+        if( item.parameterLocation >= pCode ) // the location is not inside the code (pCode points after the end)
+            continue;
         // E.g. "SUMPRODUCT(I5:I6+1)" shouldn't do implicit intersection.
         if( item.operation->IsInForceArray())
             continue;
-        ReplaceDoubleRefII( item.parameter );
+        ReplaceDoubleRefII( item.parameterLocation );
     }
     mPendingImplicitIntersectionOptimizations.clear();
 }