Small fix to Table::typed_write

When writing the realm to a new file from a write transaction,
the Table may be COW so that the top ref is changed. So don't
use the ref that is present in the group when the operation starts.

src/realm/group.cpp

@@ -943,19 +943,17 @@ ref_type Group::typed_write_tables(_impl::ArrayWriterBase& out) const
     ref_type ref = m_top.get_as_ref(1);
     if (out.only_modified && m_alloc.is_read_only(ref))
         return ref;
-    Array a(m_alloc);
-    a.init_from_ref(ref);
-    REALM_ASSERT_DEBUG(a.has_refs());
-    TempArray dest(a.size());
-    for (unsigned j = 0; j < a.size(); ++j) {
-        RefOrTagged rot = a.get_as_ref_or_tagged(j);
+    auto num_tables = m_tables.size();
+    TempArray dest(num_tables);
+    for (unsigned j = 0; j < num_tables; ++j) {
+        RefOrTagged rot = m_tables.get_as_ref_or_tagged(j);
         if (rot.is_tagged()) {
             dest.set(j, rot);
         }
         else {
             auto table = do_get_table(j);
             REALM_ASSERT_DEBUG(table);
-            dest.set_as_ref(j, table->typed_write(rot.get_as_ref(), out));
+            dest.set_as_ref(j, table->typed_write(out));
         }
     }
     return dest.write(out);

src/realm/table.cpp

@@ -3456,9 +3456,9 @@ ColKey Table::find_opposite_column(ColKey col_key) const
     return ColKey();
 }
 
-ref_type Table::typed_write(ref_type ref, _impl::ArrayWriterBase& out) const
+ref_type Table::typed_write(_impl::ArrayWriterBase& out) const
 {
-    REALM_ASSERT(ref == m_top.get_mem().get_ref());
+    auto ref = m_top.get_ref();
     if (out.only_modified && m_alloc.is_read_only(ref))
         return ref;
     out.table = this;

src/realm/table.hpp

@@ -687,7 +687,7 @@ class Table {
         Replication* const* m_repl;
     };
 
-    ref_type typed_write(ref_type ref, _impl::ArrayWriterBase& out) const;
+    ref_type typed_write(_impl::ArrayWriterBase& out) const;
 
 private:
     enum LifeCycleCookie {