fixed crash of 'tx_history -addr' command

dap_chain_node_cli.c

@@ -837,7 +837,7 @@ int dap_chain_node_cli_init(dap_config_t * g_config)
 
     // Transaction history
     dap_chain_node_cli_cmd_item_create("tx_history", com_tx_history, "Transaction history (for address or by hash)",
-            "tx_history  [-addr <addr> | -w <wallet name> -tx <tx_hash>] -net <net name> -chain <chain name>\n");
+            "tx_history  [-addr <addr> | -w <wallet name> | -tx <tx_hash>] -net <net name> -chain <chain name>\n");
     // Log
     dap_chain_node_cli_cmd_item_create ("print_log", com_print_log, "Print log info",
                 "print_log [ts_after <timestamp >] [limit <line numbers>]\n" );

dap_chain_node_cli_cmd_tx.c

@@ -595,7 +595,7 @@ char* dap_db_history_addr(dap_chain_addr_t * a_addr, dap_chain_t * a_chain)
 
         // go to next transaction
         l_atom = a_chain->callback_atom_iter_get_next(l_atom_iter);
-        l_atom_size = a_chain->callback_atom_get_size(l_atom);
+        l_atom_size = l_atom ? a_chain->callback_atom_get_size(l_atom) : 0;
     }
 
     // delete hashes