Created attachment 28371 [details]
Diff for method append on XSSFRichTextString

In our development we needed to append to a XSSFRichTextString multiple substrings each one with different font, so we used the append method. There was a problem because it removes the leading / trailing spaces and joined words. 

For example:


XSSFRichTextString text = cell.getRichStringCellValue();
text.append("Hello ");
text.append("World!");

Makes "HelloWorld!" 

and

text.append("Hello");
text.append(" World!");

also makes "HelloWorld!" 

We have modified the append method to call preserveSpaces and get "Hello World!"

Applied in r1292759 along with a unit test.

Regards,
Yegor