Unit test failing on some machine

Hi all,

I recently added a new unit test to Writer docx test suite.
It's quite simple: a single page document with one table filling all the 
page.
The test then verifies that after import/export the document has indeed 
1 page.
(see sw/qa/extras/ooxmlexport/ooxmlexport.cxx and 
sw/qa/extras/ooxmlexport/data/1-table-1-page.docx)

The problem is: on some machine, for instance 
Linux-openSUSE-x86@18-Clang Tinderbox, this test is failing like this:

code:
   CPPUNIT_ASSERT_EQUAL(sal_Int16(1), xCursor->getPage());
result:
equality assertion failed
- Expected: 1
- Actual  : 2

But on the very same machine, manually opening the docx file with 
LibreOffice lead to a 1 page document.

I tried to fix that by:
  - inserting a call to ViewShell::CalcLayout after loading the 
document, and before querying the page count => fails
  - use ViewShell::LayoutIdle instead => fails too
  - making SwModelTestBase a SfxListener, and prevent the 'calcLayout' 
method to return until SW_EVENT_LAYOUT_FINISHED event is received => 
fails too: if I block the execution, no events are received by the 
Notify function (everything is running in the same thread maybe ?)

Any ideas of what I'm doing wrong or how to fix the issue ?

Thanks!

Pierre-Eric