#5 AV in OpenGL provider on OS X 10.9.5

[Lifepower]

Reported by Devchenxip, on OS X 10.9.5, access violation:

procedure TExtensions.DecodeVersionString;
var
  VersionText: TExtString;
  CharPos: Integer;
begin
  VersionText := GetGLString(GL_VERSION); // AV here
  CharPos := 1;
  FMajorVersion := StrToIntDef(ExtractNumberWord(VersionText, CharPos), 0);
  if CharPos <= Length(VersionText) then
    FMinorVersion := StrToIntDef(ExtractNumberWord(VersionText, CharPos, 1), 0);
end;