If one merges cells in Calc, there are two options in "Format" - "Merge Cells". For the second option which is also called "Merge Cells" there is no UNDO functionality available.
How to reproduce:
1. Select a couple of cells
2. Go to "Format" -> "Merge Cells" -> "Merge Cells"
3. Result: The cells are merged, but not UNDO is possible.
Remark: For the first option, which is called "Merge and Center Cells", the UNDO functionality works like expected.
System: Ubuntu 10.10, gnome 2, English UI, LibreOffice 3.3.2 PPA.
I can reproduce it in 3.4. I think I'll fix it for 3.4.1.
Is already fixed for 3.4RC2 by Kohei with:
@Markus: Thank you very much!
Zdeněk Crhonek committed a patch related to this issue.
It has been pushed to "master":
uitest Calc merged cells- tdf#51368 tdf#105412 tdf#37901 tdf#51368 tdf#63766
It will be available in 6.1.0.
The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.
The test exist, set status to Verified.