New Runtime Version 2.21.0.5 ASort with Codeblock - IComparer.Compare() method returns inconsistent results

[christianschmid200272]

An example in which I have rebuilt the array with constant values, the error can also be reproduced with this.

FUNCTION Start() AS VOID STRICT
	LOCAL aPosListe     AS ARRAY
	aPosListe   := { }
	AAdd(aPosListe,{"Test", 1,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 0.5,	0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 6.5,	0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 0.5,	0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 4,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1.8,	0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 7,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 2,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 470,	0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"29991231B", "  /  ", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})
	AAdd(aPosListe,{"Test", 1,		0, 0,		"20191007B", "40/19", "  /  ", 0, 0, 0, 0})

	?ASort( aPosListe, , , {|x,y| x[5] <= y[5] } )

The error throwns in https://github.com/X-Sharp/XSharpPublic/blob/9b4a562c5a4d411be239f68fba9750f3d4313514/src/Runtime/XSharp.RT/Types/Array.prg#L468
, unfortunately I don't see why.

    NEW INTERNAL METHOD Sort(startIndex AS INT, count AS INT, comparer AS IComparer<__Usual>) AS VOID
        IF startIndex <= 0
            startIndex := 1
        ENDIF
        IF count < 0
            count := _internalList:Count - startIndex + __ARRAYBASE__
        ENDIF
        _internalList:Sort(startIndex-__ARRAYBASE__ ,count,comparer)
        RETURN

[RobertvanderHulst]

This is caused by the new TargetFramework Attribute. The sorting routines in the Framework have changed in .Net Framework 4.5. Before this build, withouit the attribute, the Framework was using the "old" sorting routines. Now it is using the new sorting routines.

If you look here, then you'll see that the Sort algorithm has changed in .Net 4.5:
https://learn.microsoft.com/en-us/dotnet/framework/migration-guide/runtime/4.5.x

You will most likely see different results if there are keys that have the same value.
To work around this:

• either make sure that the keys are unique
• supress the generation of the attribute by adding a property to your project file, inside the first <PropertyGroup>
<GenerateTargetFrameworkAttribute>false</GenerateTargetFrameworkAttribute>
  (this disables the build step that generates the attribute)

[RobertvanderHulst]

We will document this change and the workaround