Add mdb_cursor_is_db()

Return 1 if the cursor is pointing to a named DB record

libraries/liblmdb/lmdb.h

@@ -1506,6 +1506,13 @@ MDB_txn *mdb_cursor_txn(MDB_cursor *cursor);
 	 */
 MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor);
 
+	/** @brief Check if the cursor is pointing to a named database record.
+	 *
+	 * @param[in] cursor A cursor handle returned by #mdb_cursor_open()
+	 * @return 1 if current record is a named database, 0 otherwise.
+	 */
+int mdb_cursor_is_db(MDB_cursor *cursor);
+
 	/** @brief Retrieve by cursor.
 	 *
 	 * This function retrieves key/data pairs from the database. The address and length

libraries/liblmdb/mdb.c

@@ -9087,6 +9087,18 @@ mdb_cursor_dbi(MDB_cursor *mc)
 	return mc->mc_dbi;
 }
 
+int
+mdb_cursor_is_db(MDB_cursor *mc)
+{
+
+	if (mc && (mc->mc_flags & C_INITIALIZED) && mc->mc_snum) {
+		MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+		if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) == F_SUBDATA)
+			return 1;
+	}
+	return 0;
+}
+
 /** Replace the key for a branch node with a new key.
  * Set #MDB_TXN_ERROR on failure.
  * @param[in] mc Cursor pointing to the node to operate on.

libraries/liblmdb/mdb_dump.c

@@ -272,7 +272,7 @@ int main(int argc, char *argv[])
 		}
 		while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT_NODUP)) == 0) {
 			MDB_dbi db2;
-			if (memchr(key.mv_data, '\0', key.mv_size-1) || ((char *)key.mv_data)[key.mv_size=1] != '\0')
+			if (!mdb_cursor_is_db(cursor))
 				continue;
 			count++;
 			rc = mdb_dbi_open(txn, key.mv_data, 0, &db2);

libraries/liblmdb/mdb_stat.c

@@ -229,7 +229,7 @@ int main(int argc, char *argv[])
 		}
 		while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT_NODUP)) == 0) {
 			MDB_dbi db2;
-			if (memchr(key.mv_data, '\0', key.mv_size-1) || ((char *)key.mv_data)[key.mv_size-1] != '\0')
+			if (!mdb_cursor_is_db(cursor))
 				continue;
 			rc = mdb_dbi_open(txn, key.mv_data, 0, &db2);
 			if (rc == MDB_SUCCESS)