ITS#8355 fix subcursors

make sure C_DEL gets reset in subcursor after it moves.

libraries/liblmdb/mdb.c

@@ -6458,8 +6458,10 @@ mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 
 	DPRINTF(("cursor_next: top page is %"Y"u in cursor %p",
 		mdb_dbg_pgno(mp), (void *) mc));
-	if (mc->mc_flags & C_DEL)
+	if (mc->mc_flags & C_DEL) {
+		mc->mc_flags ^= C_DEL;
 		goto skip;
+	}
 
 	if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) {
 		DPUTS("=====> move to next sibling page");
@@ -6545,6 +6547,8 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 	DPRINTF(("cursor_prev: top page is %"Y"u in cursor %p",
 		mdb_dbg_pgno(mp), (void *) mc));
 
+	mc->mc_flags &= ~(C_EOF|C_DEL);
+
 	if (mc->mc_ki[mc->mc_top] == 0)  {
 		DPUTS("=====> move to prev sibling page");
 		if ((rc = mdb_cursor_sibling(mc, 0)) != MDB_SUCCESS) {