Comment 9 for bug 720327

Created attachment 43646
Screenshot illustrating the issue

When scrolling a sheet with merged cells, a few pixel high stripe hidden behind the column header at scroll stops is randomly dropped or duplicated, corrupting font display in the merged cells. This was not the case in OpenOffice.org 3.2.1, but was introduced during the development cycle of 3.3.0 and was imported by LibreOffice as well.

Only fonts in the merged cells are affected, not graphics. Text with line breaks in normal, not merged cells is not affected too, because Calc scrolls always row-wise.

STR:

1. Select a cell range spanning some cell rows, merge selected cells.

2. Activate "wrap text automatically" for the merged cells to get line breaks.

3. Insert a (long) text and leave the cell.

4. Vertically scroll the sheet.

Actual results: randomly dropped or duplicated horizontal stripes corrupting font display in the cell.

Both normal and page break preview are affected, forcing redraw of the cell by resizing the window or scrolling horizontally clears the font corruption.

Tested with

LibreOffice 3.3.1
OOO330m19 (Build:8)
tag libreoffice-3.3.1.2

on Ubuntu 10.10 and with the current LibreOffice package shipped with Ubuntu Natty. Downstream bug: <https://bugs.launchpad.net/ubuntu/+source/libreoffice/+bug/720327>.