Created attachment 27403 [details]
Corrupted file with comments

I have a case where uncommenting the "createCellComment()" suddenly leads to the error message "File error: data may have been lost" when the file is opened in Excel 2010.

The code for adding comments is:

	    CreationHelper createHelper = cell.getSheet().getWorkbook().getCreationHelper();
	    Sheet sheet = cell.getSheet();
	    Drawing drawingPatriarch = drawingPatriarches.get(sheet);
	    if (drawingPatriarch == null) {
	        drawingPatriarch = sheet.createDrawingPatriarch();
	        drawingPatriarches.put(sheet, drawingPatriarch);
	    }

		ClientAnchor anchor = createHelper.createClientAnchor();
		anchor.setCol1((short)4);
		anchor.setRow1(2);
		anchor.setCol2((short)10);
		anchor.setRow2(8);
		Comment comment = drawingPatriarch.createCellComment(anchor);
	    comment.setString(createHelper.createRichTextString(text));
	    cell.setCellComment(comment);


Funily it worked for a long time with the same code, but suddenly stopped working a few days ago with updated data.

This is similar to Bug 48803, but I think it may be different than this issue as it happens with different version and functionality involved.

Bug 50696 also talks about trouble with comments, but there it states that it happens when an existing file is changed, however here I am working on a new file each time.

I will attach the file that works and the one that does not work. I can not easily extract a standalone testcase for this, let me know if you need one so I spend the time only if necessary.