Created attachment 188435 [details]
A Screencast That Demonstrates How To Reproduce This

# SUMMARY

When I replace the default file extension of a file, or choose one that isn't in an application's support list, in the File Picker's “Save [Output] As…” modal, it is appended after I save that file.

Instead, because a file extension is *always* considered to be present, if a period is (always, the last period, and, in the case, of TAr files, worked backward from, with a whitelist), if a period exists in the entered filename, a file extension should not be appended.

The reason that I suggest this is: the available file type drop-down, in the File Picker's GUI, doesn't provide examples of which file extensions are associated with each type. Consequently, the user cannot know when a file extension shall be silently appended, except by prior observation.

# STEPS TO REPRODUCE

1. Invoke Konsole.

2. Enable its menu bar.

3. Select “File”.

4. Select “Save Output As…”

5. Enter `file.log`.

6. Visit the PWD in Dolphin.

# OBSERVED RESULT

`file.log.txt` shall exist there, despite RFC 5424 and RFC 6872 being `text/.*` formats. [^1] This matters, because no code editor shall provide accurate syntax highlighting for a `/plain` (`.txt`) file, so I need to remember to remove it.

# EXPECTED RESULT

I should see `file.log`. If this behaviour, for those prone to utilising periods in their filenames, might be deceptive, a small banner might be useful.

# SOFTWARE/OS VERSIONS

> ~~~
> Operating System: Fedora Linux 43
> KDE Plasma Version: 6.5.4
> KDE Frameworks Version: 6.22.0
> Qt Version: 6.10.1
> Kernel Version: 6.18.4-200.fc43.x86_64 (64-bit)
> Graphics Platform: Wayland
> ~~~

# ADDITIONAL INFORMATION

- This affects more than Konsole.

- I have reported it here, per https://bugs.kde.org/show_bug.cgi?id=510174#field_label_component:~:text=xdg-desktop-portal-kde.

[^1]: https://stackoverflow.com/questions/49689316/what-is-the-mime-type-for-log-files#comment136868859_49689362