Handling dynamic folders change during installation in Inno Setup 7

[Jack Gray (Fixxxer)]

Hi All.

Maybe I have called the topic incorrectly so I will do my best to explain what I mean.

I have an installer code that handles user's input for possible overwriting default files by the files from the backup folder. This folder user selects during installation - but there could be cases of "clean install" when user selects nothing.

So I have:

[Files]
Source: "C:\MySource\*"; Excludes: "temp\*"; DestDir: "{app}"; Flags: ignoreversion recursesubdirs createallsubdirs
Source: "{code:GetBackupFolderPage}"; DestDir: "{app}\Common"; Flags: external skipifsourcedoesntexist recursesubdirs

....

[Code]
...
function GetBackupFolderPage(Param: string): string;
var Path: string;
begin
  Path := Page.Values[0];
  If Path = '' then Result := '' else Result := Path + '\*';
end;

It works like a charm in Inno 6, but Inno 7 creates installer that causes "PathRedir: Called with empty path string." error.

Obviously it caused by inproper handling "skipifsourcedoesntexist" and "createallsubdirs" in "Files" section.