When using the "Save as" option from the File menu for an existing document, no filename is suggested for the new document. Save as dialogs in other applications always use the existing filename as the initial value, since one usually just wants to save as a different format, keeping the same name. I believe Krita behaved this way prior to the recent update as well. This bug seems to have affected earlier versions, see the related bug #342555 (now closed)
Hi Andy, Thanks for your report. I can confirm the issue. It's a regression since Krita 2.9 at least.
Git commit 3fe6ab9ea7d9d82d400428ec946525c9e6dcc2b7 by Boudewijn Rempt. Committed on 22/12/2016 at 09:00. Pushed by rempt into branch 'master'. M +6 -4 libs/widgetutils/KoFileDialog.cpp M +7 -1 libs/widgetutils/KoFileDialog.h https://commits.kde.org/krita/3fe6ab9ea7d9d82d400428ec946525c9e6dcc2b7
Git commit bf3b2d1883981a6aac25e579df4fde0aa650a4d4 by Boudewijn Rempt. Committed on 22/12/2016 at 09:01. Pushed by rempt into branch 'krita/3.1'. M +6 -4 libs/widgetutils/KoFileDialog.cpp M +7 -1 libs/widgetutils/KoFileDialog.h https://commits.kde.org/krita/bf3b2d1883981a6aac25e579df4fde0aa650a4d4