init: allow startup with -onlynet=onion -listenonion=1

It does not make sense to specify `-onlynet=onion` without providing a
Tor proxy (even if other `-onlynet=...` are given). This is checked
during startup. However, it was forgotten that a Tor proxy can also be
retrieved from "Tor control" to which we connect if `-listenonion=1`.

So, the full Tor proxy retrieval logic is:
1. get it from `-onion`
2. get it from `-proxy`
3. if `-listenonion=1`, then connect to "Tor control" and get the proxy
   from there (was forgotten before this change)

Fixes https://github.com/bitcoin/bitcoin/issues/24980

1 files changed, 14 insertions, 7 deletions

diff --git a/test/functional/feature_proxy.py b/test/functional/feature_proxy.py
index dd3cdc96ca..d02d56d068 100755
--- a/test/functional/feature_proxy.py
+++ b/test/functional/feature_proxy.py
@@ -332,20 +332,27 @@ class ProxyTest(BitcoinTestFramework):
         msg = "Error: Invalid -i2psam address or hostname: 'def:xyz'"
         self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
 
+        self.log.info("Test passing -onlynet=onion with -onion=0/-noonion raises expected init error")
         msg = (
             "Error: Outbound connections restricted to Tor (-onlynet=onion) but "
-            "the proxy for reaching the Tor network is not provided (no -proxy= "
-            "and no -onion= given) or it is explicitly forbidden (-onion=0)"
+            "the proxy for reaching the Tor network is explicitly forbidden: -onion=0"
         )
-        self.log.info("Test passing -onlynet=onion without -proxy or -onion raises expected init error")
-        self.nodes[1].extra_args = ["-onlynet=onion"]
-        self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
-
-        self.log.info("Test passing -onlynet=onion with -onion=0/-noonion raises expected init error")
         for arg in ["-onion=0", "-noonion"]:
             self.nodes[1].extra_args = ["-onlynet=onion", arg]
             self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
 
+        self.log.info("Test passing -onlynet=onion without -proxy, -onion or -listenonion raises expected init error")
+        self.nodes[1].extra_args = ["-onlynet=onion", "-listenonion=0"]
+        msg = (
+            "Error: Outbound connections restricted to Tor (-onlynet=onion) but the proxy for "
+            "reaching the Tor network is not provided: none of -proxy, -onion or -listenonion is given"
+        )
+        self.nodes[1].assert_start_raises_init_error(expected_msg=msg)
+
+        self.log.info("Test passing -onlynet=onion without -proxy or -onion but with -listenonion=1 is ok")
+        self.start_node(1, extra_args=["-onlynet=onion", "-listenonion=1"])
+        self.stop_node(1)
+
         self.log.info("Test passing unknown network to -onlynet raises expected init error")
         self.nodes[1].extra_args = ["-onlynet=abc"]
         msg = "Error: Unknown network specified in -onlynet: 'abc'"