tdf#105852: don't merge cells if there were no merge continuation

In RTF, it's possible to start a cells merge using \clmgf, and simply
omit following cells in the row - they must merge automatically.
This makes HorizontallyMergedCell::m_nLastCol/Row uninitialized.
Previously, the uninitialized values arrived as 0,0 - thus the first
range's cell got merged with cell 0,0.

This change prevents the merge; in scenario above, absence of additional
cells in row will create merged cell automatically.

Change-Id: I68b84b7ec70d9512c541a077689369fa4a8dc0c5
Reviewed-on: https://gerrit.libreoffice.org/34079Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Tested-by: Mike Kaganski <mike.kaganski@collabora.com>

sw/qa/extras/rtfimport/data/tdf105852.rtf

+{\rtf1\ansicpg1251
+
+{\trowd
+\cellx720
+\cellx6240
+\cellx7680
+\cellx9360
+A1\cell
+A2\cell
+A3\cell
+A4\cell
+\row}
+{\trowd
+\cellx720
+\cellx6240
+\cellx7680
+\cellx9360
+B1\cell
+B2\cell
+B3\cell
+B4\cell
+\row}
+{\trowd
+\clmgf\cellx9360
+C1\cell
+\row}
+{\trowd
+\cellx720
+\cellx6240
+\cellx7680
+\cellx9360
+D1\cell
+D2\cell
+D3\cell
+D4\cell
+\row}
+{\trowd
+\clmgf\cellx9360
+E1\cell
+\row}
+{\trowd
+\cellx720
+\cellx6240
+\cellx7680
+\cellx9360
+F1\cell
+F2\cell
+F3\cell
+F4\cell
+\row}\par}
\ No newline at end of file

sw/qa/extras/rtfimport/rtfimport.cxx

@@ -2765,6 +2765,20 @@ DECLARE_RTFIMPORT_TEST(testTdf104744, "tdf104744.rtf")
     CPPUNIT_ASSERT_EQUAL(static_cast<sal_Int32>(1270), getProperty<sal_Int32>(getParagraph(1), "ParaLeftMargin"));
 }
 
+DECLARE_RTFIMPORT_TEST(testTdf105852, "tdf105852.rtf")
+{
+    uno::Reference<text::XTextTablesSupplier> xTablesSupplier(mxComponent, uno::UNO_QUERY);
+    uno::Reference<container::XIndexAccess> xTables(xTablesSupplier->getTextTables(), uno::UNO_QUERY);
+    uno::Reference<text::XTextTable> xTextTable(xTables->getByIndex(0), uno::UNO_QUERY);
+    uno::Reference<table::XTableRows> xTableRows(xTextTable->getRows(), uno::UNO_QUERY);
+    // All rows but last were merged -> there were only 2 rows
+    CPPUNIT_ASSERT_EQUAL(sal_Int32(6), xTableRows->getCount());
+    // The first row must have 4 cells.
+    CPPUNIT_ASSERT_EQUAL(sal_Int32(3), getProperty< uno::Sequence<text::TableColumnSeparator> >(xTableRows->getByIndex(0), "TableColumnSeparators").getLength());
+    // The third row must have 1 merged cell.
+    CPPUNIT_ASSERT_EQUAL(sal_Int32(0), getProperty< uno::Sequence<text::TableColumnSeparator> >(xTableRows->getByIndex(2), "TableColumnSeparators").getLength());
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

writerfilter/source/dmapper/DomainMapperTableHandler.cxx

@@ -1042,12 +1042,16 @@ void DomainMapperTableHandler::endTable(unsigned int nestedTableLevel, bool bTab
                             uno::Reference<table::XCellRange> xCellRange(xTable, uno::UNO_QUERY_THROW);
                             uno::Reference<beans::XPropertySet> xCell(xCellRange->getCellByPosition(it->m_nFirstCol, it->m_nFirstRow), uno::UNO_QUERY_THROW);
                             OUString aFirst = xCell->getPropertyValue("CellName").get<OUString>();
-                            xCell.set(xCellRange->getCellByPosition(it->m_nLastCol, it->m_nLastRow), uno::UNO_QUERY_THROW);
-                            OUString aLast = xCell->getPropertyValue("CellName").get<OUString>();
+                            // tdf#105852: Only try to merge if m_nLastCol is set (i.e. there were some merge continuation cells)
+                            if (it->m_nLastCol != -1)
+                            {
+                                xCell.set(xCellRange->getCellByPosition(it->m_nLastCol, it->m_nLastRow), uno::UNO_QUERY_THROW);
+                                OUString aLast = xCell->getPropertyValue("CellName").get<OUString>();
 
-                            uno::Reference<text::XTextTableCursor> xCursor = xTable->createCursorByCellName(aFirst);
-                            xCursor->gotoCellByName(aLast, true);
-                            xCursor->mergeRange();
+                                uno::Reference<text::XTextTableCursor> xCursor = xTable->createCursorByCellName(aFirst);
+                                xCursor->gotoCellByName(aLast, true);
+                                xCursor->mergeRange();
+                            }
                         }
                     }
                 }

writerfilter/source/dmapper/DomainMapperTableHandler.hxx

@@ -50,8 +50,8 @@ struct HorizontallyMergedCell
     HorizontallyMergedCell(sal_Int32 nFirstRow, sal_Int32 nFirstCol)
         : m_nFirstRow(nFirstRow)
         , m_nFirstCol(nFirstCol)
-        , m_nLastRow(0)
-        , m_nLastCol(0)
+        , m_nLastRow(nFirstRow)
+        , m_nLastCol(-1)
     {
     }
 };