As I want digikam to access the database from ram I configured it to store its database in /tmp. Therefore I changed this line in digikamrc:
    Database Name=/tmp/digikam-db/
    Database Name Face=/tmp/digikam-db/
As the thumbnails database is way too big to be stored in ram I want it to be located on my harddisk:
    Database Name Thumbnails=/media/ntfs_data/Programme/AppDaten/digikam5/thumbnails-digikam.db
When I start digikam (with my old database or completely clean start) these values are automatically set to:
    Database Name=/tmp/digikam-db/
    Database Name Face=/tmp/digikam-db/
    Database Name Thumbnails=/tmp/digikam-db/
Individual storage places are essential for my use case.


Reproducible: Always

Steps to Reproduce:
1. Add different locations "Database Name" and "Database Name Thumbnails" in digikamrc
2. Start digikam

Actual Results:  
"Database Name Thumbnails" is set to the same location as "Database Name" 

Expected Results:  
"Database Name Thumbnails" remains separate from "Database Name" and thus the thumbnail database is located at a different location than the main digikam database.

I used digikam compiled from commit "19446b5" when this happened.