forcepoint#79 FindStartEndOfRowSpanCell returning null

Change-Id: I85f5b17b7dc2d3c4dfef92f64451fab451f58112
Reviewed-on: https://gerrit.libreoffice.org/70927
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sw/qa/extras/layout/layout.cxx

@@ -2564,6 +2564,9 @@ CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testForcepoint75)
 //just care it doesn't crash/assert
 CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testForcepoint76) { createDoc("forcepoint76-1.rtf"); }
 
+//just care it doesn't crash/assert
+CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testForcepoint79) { createDoc("forcepoint79-1.doc"); }
+
 CPPUNIT_TEST_FIXTURE(SwLayoutWriter, testTdf118058)
 {
     SwDoc* pDoc = createDoc("tdf118058.fodt");

sw/source/core/layout/findfrm.cxx

@@ -1668,8 +1668,6 @@ SwCellFrame* SwCellFrame::GetPreviousCell() const
 // --> NEW TABLES
 const SwCellFrame& SwCellFrame::FindStartEndOfRowSpanCell( bool bStart ) const
 {
-    const SwCellFrame* pRet = nullptr;
-
     const SwTabFrame* pTableFrame = dynamic_cast<const SwTabFrame*>(GetUpper()->GetUpper());
 
     if ( !bStart && pTableFrame && pTableFrame->IsFollow() && pTableFrame->IsInHeadline( *this ) )
@@ -1726,17 +1724,17 @@ const SwCellFrame& SwCellFrame::FindStartEndOfRowSpanCell( bool bStart ) const
 
                 if ( pMasterTable == pTableFrame )
                 {
-                    pRet = pMasterCell;
-                    break;
+                    return *pMasterCell;
                 }
             }
         }
     }
 
-    assert(pRet && "SwCellFrame::FindStartRowSpanCell: No result");
+    SAL_WARN("sw.core", "SwCellFrame::FindStartRowSpanCell: No result");
 
-    return *pRet;
+    return *this;
 }
+
 // <-- NEW TABLES
 
 const SwRowFrame* SwFrame::IsInSplitTableRow() const