Steps to reproduce:
1. Merge A1 and A2
2. Mark A1:A3
3. Merge cells
Gives: "Cell merge not possible if cells already merged"
Same behaviour as split cells followed by merge cells. Or at least a better explanation why the system cannot just split+merge.
Operating System: Linux (Other)
Version: 184.108.40.206 release
*** This bug has been marked as a duplicate of bug 63766 ***