Spectacle uses the built-in Qt file picker instead of the one provided by the system (i.e. kdialog). It's missing a lot of features, is therefore cumbersome to use and doesn't integrate well with the rest of the desktop. As part of the KDE family, Spectacle should really use the provided platform tools. Reproducible: Always
This is an intentional change. I'm waiting for a bugfix in KDialog's filter-by-file-type.
What filter bug are you talking about? Bug 319502? That's the only bug report I can find about filters and I'm not even sure if that's really a kdialog bug or rather a PyQt4 bug (and in PyQt5 there isn't even a method QFileDialog.getOpenFileNameAndFilter()). The file dialog used by Spectacle is just utterly useless. It doesn't even show file/folder icons which makes it really hard to tell files and folders apart. All my bookmarks etc. are also missing. It's about as ugly and hard to use the the GtkFileChooserDialog (which IMHO is one of the ugliest pices of any GUI framework ever produced). I'm not quite sure what filter bug you mean, but I would glady accept some issues with file filters in exchange for a proper file dialog.
Janek, see bug 357865.
See bug 369174 for the commit details.