Created attachment 38438 [details]
Expected borders and reality

Hi there,

I'm facing an issue trying to set borders on an merged region applying a Row Span. The version I uesd is 5.2.3 but not listed here.

the code used bellow :

if (!BorderStyle.NONE.equals(excelStyle.getBorderBottom())) {
  RegionUtil.setBorderBottom(excelStyle.getBorderBottom(), mergedRegion, excelSheet);
  RegionUtil.setBottomBorderColor(excelStyle.getBottomBorderColor(), mergedRegion, excelSheet);
}

if (!BorderStyle.NONE.equals(excelStyle.getBorderTop())) {
  RegionUtil.setBorderTop(excelStyle.getBorderTop(), mergedRegion, excelSheet);
  RegionUtil.setTopBorderColor(excelStyle.getTopBorderColor(), mergedRegion, excelSheet);
}

if (!BorderStyle.NONE.equals(excelStyle.getBorderLeft())) {
  RegionUtil.setBorderLeft(excelStyle.getBorderLeft(), mergedRegion, excelSheet);
  RegionUtil.setLeftBorderColor(excelStyle.getLeftBorderColor(), mergedRegion, excelSheet);
}

if (!BorderStyle.NONE.equals(excelStyle.getBorderRight())) {
  RegionUtil.setBorderRight(excelStyle.getBorderRight(), mergedRegion, excelSheet);
  RegionUtil.setRightBorderColor(excelStyle.getRightBorderColor(), mergedRegion, excelSheet);
}

In my tests i go throughout all conditions, this works good for the Column span, But for the Row span the behavior of the borders isn't the one I expected (see the attachments).

The script of the code is this : 

 - I compute the XSSFCellStyle
 - Then I apply the style to the current cell
 - And finaly, if a span is defined on this cell, I create a CellRangeAddress, add it to the merged regions and apply the borders with the code above.

I try differents scripts (create the merged region before applying styles...) but the result is always the same as the attachment. 

Is this a bug or I missused RegionUtil ?

Thanks.