tests: Test connecting with non-existing RPC cookie file

test/functional/interface_bitcoin_cli.py

@@ -38,6 +38,9 @@ class TestBitcoinCli(BitcoinTestFramework):
         self.log.info("Test connecting to a non-existing server")
         assert_raises_process_error(1, "Could not connect to the server", self.nodes[0].cli('-rpcport=1').echo)
 
+        self.log.info("Test connecting with non-existing RPC cookie file")
+        assert_raises_process_error(1, "Could not locate RPC credentials", self.nodes[0].cli('-rpccookiefile=does-not-exist', '-rpcpassword=').echo)
+
         self.log.info("Make sure that -getinfo with arguments fails")
         assert_raises_process_error(1, "-getinfo takes no arguments", self.nodes[0].cli('-getinfo').help)