In D10099#197558, @ngraham wrote:

Great, works fine now. I'm formally accepting it, but won't land it yet, pending possible future work on the other template. Alternatively, I can land it now, and you can do the other thing in another patch. Your choice.

In D10099#197451, @michaelh wrote:

how do we present user with such template?

My guess

kdegraphics/spectacle/src/Gui/SettingsDialog/SaveOptionsPage.cpp:95

Ah, got it. I was thinking about second field to introduce this template, don't know why (question about "both" empty templates originates here).

In D10099#197406, @michaelh wrote:

How about introducing another template like '%#' ...

Question is: how do we present user with such template? We have one, and this patch fixes behavior when it is empty. How to describe this new template? What will we do when both are empty?

Fixed "Save As" file naming with empty filename template

In D10099#197406, @michaelh wrote:

How about introducing another template like '%#' instead of hard coding the '1'?
This would also allow for %#### to pad with zeros.

In D10099#197151, @ngraham wrote:

Thanks for the patch! Does what it says it does, but I found a corner case: if you delete the template and choose "Save As...", the file save dialog box uses a default filename of ".png". We probably need to add the number there, too.