Missing w:separator attribute in OOXML file

Hi everyone!

We encountered a problem while opening an OOXML file with footnotes. 
There is no "w:separator" attribute in the source file and the 
representation between Word 2013 and current LO master differs:

- Word 2013 shows the separator line
- LO master hides the separator line

A little investigation lead to the fact that LO creates a separator line 
with zero length. This behavior was introduced by Miklos in the commit 
330b860205c7ba69dd6603f65324d0f89ad9cd5f back in 2013.

When I save the document in Word 2013 (even in compatibility modes) the 
result always contains a "w:separator" attribute and thus, LO shows the 
line.

(unfortunately, I cannot add the file due to privacy reasons. Every 
attempt to anonymize the file leads the a w:separator attibute in the file)

Has the behavior of Word changed? Reading the commit message, it seems 
like in the past Word does not show the separator when the attribute is 
missing. Word 2013 shows the line.


Thanks,
Patrick