tdf#140137 Don't throw exception when w:gridCol is missing "w" attr

2149e924cbc32c370128c5f87a4f55c50c99e6bd added a division-by-zero
check, which caused Writer to throw an error on the bugdoc.
Since the file could be loaded fine before, let's return to a
working version, with the check included.

The cause is the following in document.xml
(originating from a non-MS generator):
  <w:tblGrid>
      <w:gridCol/>
      <w:gridCol/>
  </w:tblGrid>

Word still splits such tables differently, but that difference
was always there in Writer.

Change-Id: I6d91a736f460394a76f035298a238c41da201cb3
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111723
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Signed-off-by: Xisco Fauli <xiscofauli@libreoffice.org>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111736
Signed-off-by: Xisco Fauli <xiscofauli@libreoffice.org>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111741

1 files changed, 13 insertions, 5 deletions

diff --git a/writerfilter/source/dmapper/DomainMapperTableManager.cxx b/writerfilter/source/dmapper/DomainMapperTableManager.cxx
index a19b9395e192..84b959e4e6ba 100644
--- a/writerfilter/source/dmapper/DomainMapperTableManager.cxx
+++ b/writerfilter/source/dmapper/DomainMapperTableManager.cxx
@@ -726,17 +726,25 @@ void DomainMapperTableManager::endOfRowAction()
         size_t nWidthsBound = m_aGridBefore.back() + m_nCell.back() - 1;
         if (nWidthsBound)
         {
-            if (nFullWidthRelative == 0)
-                throw o3tl::divide_by_zero();
-
             ::std::vector< sal_Int32 >::const_iterator aSpansIter = pCurrentSpans->begin( );
             for( size_t nBorder = 0; nBorder < nWidthsBound; ++nBorder )
             {
-                double fGridWidth = 0.;
+                double nRelPos, fGridWidth = 0.;
                 for ( sal_Int32 nGridCount = *aSpansIter; nGridCount > 0; --nGridCount )
                     fGridWidth += (*pTableGrid)[nBorderGridIndex++];
 
-                double nRelPos = (fGridWidth * 10000) / nFullWidthRelative;
+                if (fGridWidth == 0.)
+                {
+                    // allow nFullWidthRelative here, with a sane 0.0 result
+                    nRelPos = 0.;
+                }
+                else
+                {
+                    if (nFullWidthRelative == 0)
+                        throw o3tl::divide_by_zero();
+
+                    nRelPos = (fGridWidth * 10000) / nFullWidthRelative;
+                }
 
                 pSeparators[nBorder].Position = rtl::math::round(nRelPos + nLastRelPos);
                 pSeparators[nBorder].IsVisible = true;