RTF filter: add URW testcase

lcov points out this was uncovered previously.

Change-Id: I831b7e6c2b475d2b3ddd64fb21714c3b6667832a
Reviewed-on: https://gerrit.libreoffice.org/65944
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

sw/qa/extras/rtfexport/data/ulw.rtf

+{\rtf1\ulw Aaa bbb.\par}

sw/qa/extras/rtfexport/rtfexport3.cxx

@@ -218,6 +218,12 @@ DECLARE_RTFEXPORT_TEST(testTdf122424_textOutsideCellInATableRow, "tdf122424.rtf"
     CPPUNIT_ASSERT_EQUAL(OUString("cell3"), xCell->getString());
 }
 
+DECLARE_RTFEXPORT_TEST(testUlw, "ulw.rtf")
+{
+    // Test underlying in individual words mode.
+    CPPUNIT_ASSERT(getProperty<bool>(getRun(getParagraph(1), 1), "CharWordMode"));
+}
+
 CPPUNIT_PLUGIN_IMPLEMENT();
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */