XLIFF Word-Count Splitter: extra part is produced on even split

[Denis Konovalyenko]

Copied from issue #1156:

Also, it looks like there’s a secondary bug where if the word count threshold divides evenly into the total word count of the file, an empty part is produced. In this case, there are 4 words in the source file, and splitting at 2 words produces 3 split parts, one of them containing no trans-units. This is a more unlikely edge case in the real world, so it doesn’t have to be fixed here unless it’s easy to add.

Thoughts:

The creation of the extra empty part (without text units) is connected with how the document is read - in one pass. There may probably be used some pre-reading of events with followed searching for text-unit tags. I can assume if no text unit is found, a new part mustn't be started in this case.