Steps to Reproduce

1. run the test page keikai.test/alignment/1338-overflow-right-align.zul
2. click the 2nd "freeze" sheet
3. check C1

Current Result

Expected Result

the text overflows to the right cell

Debug Information

The zss implementation for such overflow is done by 2 cells, 1 cell on left frozen and 1 cell on the activeBlock to compose the whole overflowed text.
In keikai, the activeBlock now doesn't contain cell data of frozen columns, so need to find another way to achieve such overflow.