delete-old.pascal

[Code]
function PrepareToInstall(var NeedsRestart: Boolean): String;
var
    FileResult: TFindRec;
    AppDir: string;
begin
    if FindFirst(ExpandConstant('{app}\'), FileResult) then
    begin
        try
            repeat
                if (FileResult.Name = '.') or (FileResult.Name = '..') or (FileResult.Name = 'config') then
                begin
                    Log('Deletion skipped: ' + FileResult.Name);
                    continue;
                end;

                Log('Delete: ' + ExpandConstant('{app}\' + FileResult.Name));
                DelTree(ExpandConstant('{app}\' + FileResult.Name), FileResult.Attributes and FILE_ATTRIBUTE_DIRECTORY = FILE_ATTRIBUTE_DIRECTORY, True, True);
            until not FindNext(FileResult);
        finally
            FindClose(FileResult);
        end;
    end;
end;