Geolocation Editor: remove altitude context menu not working as expected

[NeiNei]

Hi there,

Perhaps I have a conceptual misunderstanding but I face an issue in the 
geolocation editor when I try to remove altitude values in the metadata 
of my jpeg photos.

*Situation:
I select an image in thumbnail view and open then the geolocation editor.
In the geolocation editor I select the Details tab.
In the details tab I select an image containing gps coordinates and 
altitude data. Coordinates and altitude data are correctly shown
For the selected picture I right-click the context menu and choose 
“remove altitude”.
The altitude value is removed and the altitude filed is now empty.
I press apply and close the geolocation editor.

I reopen the geolocation editor.
In the details tab I select the same image. In the details tab I see the 
gps coordinates and an altitude value of 0 (zero) meters.


*Expectation:
I would expect an empty field instead of 0 meters. The latter represents 
sea level for me.


*My interpretation:
“Remove altitude” does not empty the metadata field altitude as intended 
but writes 0 meters in it.

*Further observations:
The issue remains whether I reread the metadata of the jpeg or not.
It doe not matter if I select on or several jpeg images and remove 
altitude on them.
If I use “Remove coordinates” instead gps coordinates and the altitude 
values is removed and the fields stay empty on reopening the same image 
in the geolocation editor.
I observed the issue in DK 5.7 (KDE Neon) and in Win64 DK 5.8 built of 
November 30th as well in DK 5.8 app image for Linux from last week.

So, could someone give me a hint on this or could reproduce this behavior?

Thanks in advance,
NeiNei