net: Print error message if -proxy is specified without arguments (instead of continuing without proxy server)

2 files changed, 11 insertions, 0 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 132acbfc81..ee9ec633b5 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1176,6 +1176,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
 
     nMaxTipAge = args.GetArg("-maxtipage", DEFAULT_MAX_TIP_AGE);
 
+    if (args.IsArgSet("-proxy") && args.GetArg("-proxy", "").empty()) {
+        return InitError(_("No proxy server specified. Use -proxy=<ip> or -proxy=<ip:port>."));
+    }
+
     return true;
 }
 
diff --git a/test/functional/feature_config_args.py b/test/functional/feature_config_args.py
index 34e856c1ba..b4355a6587 100755
--- a/test/functional/feature_config_args.py
+++ b/test/functional/feature_config_args.py
@@ -78,6 +78,12 @@ class ConfArgsTest(BitcoinTestFramework):
         with open(inc_conf_file2_path, 'w', encoding='utf-8') as conf:
             conf.write('')  # clear
 
+    def test_invalid_command_line_options(self):
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: No proxy server specified. Use -proxy=<ip> or -proxy=<ip:port>.',
+            extra_args=['-proxy'],
+        )
+
     def test_log_buffer(self):
         with self.nodes[0].assert_debug_log(expected_msgs=['Warning: parsed potentially confusing double-negative -connect=0\n']):
             self.start_node(0, extra_args=['-noconnect=0'])
@@ -146,6 +152,7 @@ class ConfArgsTest(BitcoinTestFramework):
         self.test_networkactive()
 
         self.test_config_file_parser()
+        self.test_invalid_command_line_options()
 
         # Remove the -datadir argument so it doesn't override the config file
         self.nodes[0].args = [arg for arg in self.nodes[0].args if not arg.startswith("-datadir")]