OpenXML: text runs containing only <w:br/> lost during merge

[Chase Tingley]

Testcase attached. This file contains several lines with forced line breaks (<w:br/>) used as spacing. These line breaks are stored in their own dedicated text runs.

To reproduce, roundtrip it through OpenXML filter, eg:

tikal.sh -fc okf_openxml -x br.docx
tikal.sh -fc okf_openxml -m br.docx.xlf

In the roundtripped file, these line break runs have been stripped, and the spacing of the document is messed up.

[Chase Tingley]

Fixed in commit 10654c7d.

The issue here was that this structure is represented as two runs, each consisting only of <w:br/>. These were being merged into a single run by combineRepeatedFormat() during parsing, because that method didn't know about the br element.