tdf#90816: sw: fix bookmark loss in SwUndoDelete

_DelBookmarks() will actually delete marks that exactly match both start
and end position of the range, so restrict the call to only the
fully-deleted nodes that will be moved to the Undo-array.

(regression from 370febbf)

Change-Id: Icf5097774aa55ee152a1e20c0c7264330955c615

sw/qa/core/macros-test.cxx

@@ -79,6 +79,7 @@ public:
     void testVba();
 #endif
     void testBookmarkDeleteAndJoin();
+    void testBookmarkDeleteTdf90816();
 #if 0
     void testControlShapeGrouping();
 #endif
@@ -93,6 +94,7 @@ public:
     CPPUNIT_TEST(testVba);
 #endif
     CPPUNIT_TEST(testBookmarkDeleteAndJoin);
+    CPPUNIT_TEST(testBookmarkDeleteTdf90816);
 #if 0
     CPPUNIT_TEST(testControlShapeGrouping);
 #endif
@@ -222,6 +224,35 @@ void SwMacrosTest::testBookmarkDeleteAndJoin()
     }
 }
 
+void SwMacrosTest::testBookmarkDeleteTdf90816()
+{
+    SwDoc *const pDoc = new SwDoc;
+    pDoc->GetIDocumentUndoRedo().DoUndo(true); // bug is in SwUndoDelete
+    SwNodeIndex aIdx(pDoc->GetNodes().GetEndOfContent(), -1);
+    SwPaM aPaM(aIdx);
+
+    IDocumentContentOperations & rIDCO(pDoc->getIDocumentContentOperations());
+    rIDCO.AppendTxtNode(*aPaM.GetPoint());
+    rIDCO.InsertString(aPaM, OUString("ABC"));
+    aPaM.Move(fnMoveBackward, fnGoCntnt);
+    aPaM.SetMark();
+    aPaM.Move(fnMoveBackward, fnGoCntnt);
+    IDocumentMarkAccess & rIDMA = *pDoc->getIDocumentMarkAccess();
+    sw::mark::IMark *pMark =
+        rIDMA.makeMark(aPaM, "test", IDocumentMarkAccess::MarkType::BOOKMARK);
+    CPPUNIT_ASSERT(pMark);
+
+    // delete the same selection as the bookmark
+    rIDCO.DeleteAndJoin(aPaM, false);
+
+    // bookmark still there?
+    auto iter = rIDMA.getAllMarksBegin();
+    CPPUNIT_ASSERT_MESSAGE("the bookmark was deleted",
+            iter != rIDMA.getAllMarksEnd());
+    CPPUNIT_ASSERT(*aPaM.Start() == (*iter)->GetMarkPos());
+    CPPUNIT_ASSERT(*aPaM.End() == (*iter)->GetOtherMarkPos());
+}
+
 #if 0
 void SwMacrosTest::testControlShapeGrouping()
 {

sw/source/core/undo/undel.cxx

@@ -154,7 +154,11 @@ SwUndoDelete::SwUndoDelete(
     {
         DelCntntIndex( *rPam.GetMark(), *rPam.GetPoint() );
         ::sw::UndoGuard const undoGuard(pDoc->GetIDocumentUndoRedo());
-        _DelBookmarks(pStt->nNode, pEnd->nNode, nullptr, &pStt->nContent, &pEnd->nContent);
+        if (nEndNode - nSttNode > 1) // check for fully selected nodes
+        {
+            SwNodeIndex const start(pStt->nNode, +1);
+            _DelBookmarks(start, pEnd->nNode);
+        }
     }
 
     nSetPos = pHistory ? pHistory->Count() : 0;