The code below opens the expected dialog window but doesn't set the passed filters. Since it doesn't set any filters, no file can be selected - until one types the filters manually. I think the bug was introduced with the latest revision of KDE Frameworks, i.e. version 5.36.0. kdialog --getopenfilename /tmp/ ".tar.gz"
Pardon me! It must have been introduced with KDE Applications 17.04.3, naturally. :)
kdialog --getopenfile /tmp/ "Tar File (*.tar.gz)" is the official glob type syntax and works. I am not sure if your glob without a name and a correct pattern worked because of a bug, or if it was a documented feature.
Thanks for your answer! That works indeed. It used to work without wildcard. But it's correct to presume it's use. So I'd say, this is not a bug, but I would like to propse to add another helpline to kdialog --help, since filters can be used for several functions. Something like that: Arguments: [arg] Arguments - depending on main option [filter] File type filter - usage: "*.xml" or "XML file (*.xml)"