Version:           1.6.1 (using KDE 4.6.2) 
OS:                Linux

In Dolphin, when I add one tag to several files which already have their individual tags, these are gone afterwards, replaced only by the new tag.
Btw, the respective link e.g. in the information panel says "Add tags ..." (or similar - I'm using the German version: "Stichwörter hinzufügen ..."), so one may be tempted to think it actually adds them to the existing ones.

Reproducible: Always

Steps to Reproduce:
1. Open a folder with several files in it in Dolphin.
2. Assign at least two files arbitrary tags.
3. Mark these files.
4. In the information panel, or in the files' properties dialog, information tab, click on the link to add new tags ("Stichwörter hinzufügen ..." in German).
5. Check at least one tag, different from the earlier ones, click ok.


Actual Results:  
The files now all have the new tag(s) only.

Expected Results:  
Each file should be assigned the union of its earlier tags with the additional tags.

OS: Linux (x86_64) release 2.6.38-8-generic
Compiler: cc