tdf#101826 ww8import: add XATTR_* to textbox attr set

Somewhat magically, just adding XATTR to the FlySet makes
background colors/gradients/images appear. This has been
broken since XATTR was introduced in LO 4.3.

Change-Id: I84554045f49618a5eb927edfebdf641c5a93b673
Reviewed-on: https://gerrit.libreoffice.org/66310
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>

sw/qa/extras/ww8export/ww8export.cxx

@@ -1303,6 +1303,9 @@ DECLARE_WW8EXPORT_TEST(testTdf76349_textboxMargins, "tdf76349_textboxMargins.doc
 {
     // textboxes without borders were losing their spacing items in round-tripping
     CPPUNIT_ASSERT( 0 < parseDump("/root/page/body/txt/anchored/fly/infos/prtBounds", "left").toInt32() );
+
+    uno::Reference<drawing::XShape> xShape = getShape(1);
+    CPPUNIT_ASSERT_EQUAL_MESSAGE("Textbox background color", Color(0xD8, 0xD8, 0xD8), getProperty<Color>(xShape, "BackColor"));
 }
 
 DECLARE_WW8EXPORT_TEST(testMoveRange, "fdo66304-1.odt")

sw/source/filter/ww8/ww8graf.cxx

@@ -1149,7 +1149,7 @@ void SwWW8ImplReader::InsertTxbxText(SdrTextObj* pTextObj,
                 if( pFlyFormat && pRecord )
                 {
                     SfxItemSet aFlySet( m_rDoc.GetAttrPool(),
-                        svl::Items<RES_FRMATR_BEGIN, RES_FRMATR_END-1>{} );
+                        svl::Items<RES_FRMATR_BEGIN, RES_FRMATR_END-1, XATTR_START, XATTR_END>{} );
 
                     tools::Rectangle aInnerDist(   pRecord->nDxTextLeft,
                                              pRecord->nDyTextTop,
@@ -2552,7 +2552,7 @@ SwFrameFormat* SwWW8ImplReader::Read_GrafLayer( long nGrafAnchorCp )
     // when in a header or footer word appears to treat all elements as wrap through
 
     // determine wrapping mode
-    SfxItemSet aFlySet(m_rDoc.GetAttrPool(), svl::Items<RES_FRMATR_BEGIN, RES_FRMATR_END-1>{});
+    SfxItemSet aFlySet(m_rDoc.GetAttrPool(), svl::Items<RES_FRMATR_BEGIN, RES_FRMATR_END-1, XATTR_START, XATTR_END>{});
     Reader::ResetFrameFormatAttrs(aFlySet); // tdf#122425: Explicitly remove borders and spacing
     css::text::WrapTextMode eSurround = css::text::WrapTextMode_PARALLEL;
     bool bContour = false;