Add allowExisting option for name_new.

domob1812 · domob1812 · commit 3589732bcd67 · 2018-07-06T08:50:37.000+02:00
In namecoin/namecoin-core#54, it was suggested to disallow name_new for already existing names in the RPC interface by default (while of course still allowing those on the consensus level). This change leverages the new "options" argument for name_new to implement this: We add a new "allowExisting" option in the JSON object, false by default, and raise an error for name_new with an existing name unless this option is explicitly set to true.
diff --git a/doc/release-notes-namecoin.md b/doc/release-notes-namecoin.md
@@ -34,3 +34,10 @@
   name RPCs like `name_show` or `name_scan`.
   See the [proposal](https://github.com/namecoin/namecoin-core/issues/219) and
   the [implementation](https://github.com/namecoin/namecoin-core/pull/236).
+
+- `name_new` now checks whether a name exists already and by default rejects
+  to register an already existing name.  To override this check and get back
+  the old behaviour (where a `NAME_NEW` transaction can be sent for existing
+  names), set the new `allowExisting` option to true.
+  For more context, see the
+  [corresponding issue](https://github.com/namecoin/namecoin-core/issues/54).
diff --git a/src/wallet/rpcnames.cpp b/src/wallet/rpcnames.cpp
@@ -357,6 +357,9 @@ name_new (const JSONRPCRequest& request)
         "1. \"name\"          (string, required) the name to register\n"
         "2. \"options\"       (object, optional)\n"
         + NameOpOptionsHelpBuilder ()
+            .withField ("\"allowExisting\"",
+                        "(boolean, optional, default=false) If set, then the"
+                        " name_new is sent even if the name exists already")
             .finish ("") +
         "\nResult:\n"
         "[\n"
@@ -378,6 +381,19 @@ name_new (const JSONRPCRequest& request)
   UniValue options(UniValue::VOBJ);
   if (request.params.size () >= 2)
     options = request.params[1].get_obj ();
+  RPCTypeCheckObj (options,
+    {
+      {"allowExisting", UniValueType (UniValue::VBOOL)},
+    },
+    true, false);
+
+  if (!options["allowExisting"].isTrue ())
+    {
+      LOCK (cs_main);
+      CNameData oldData;
+      if (pcoinsTip->GetName (name, oldData) && !oldData.isExpired ())
+        throw JSONRPCError (RPC_TRANSACTION_ERROR, "this name exists already");
+    }
 
   valtype rand(20);
   GetRandBytes (&rand[0], rand.size ());
diff --git a/test/functional/name_registration.py b/test/functional/name_registration.py
@@ -71,6 +71,17 @@ def run_test (self):
     self.checkNameHistory (1, "node-0", ["value-0"])
     self.checkNameHistory (1, "node-1", ["x" * 520])
 
+    # Verify the allowExisting option for name_new.
+    assert_raises_rpc_error (-25, 'exists already',
+                             self.nodes[0].name_new, "node-0")
+    assert_raises_rpc_error (-25, 'exists already',
+                             self.nodes[0].name_new, "node-0",
+                             {"allowExisting": False})
+    assert_raises_rpc_error (-3, 'Expected type bool for allowExisting',
+                             self.nodes[0].name_new, "other",
+                             {"allowExisting": 42.5})
+    self.nodes[0].name_new ("node-0", {"allowExisting": True})
+
     # Check for error with rand mismatch (wrong name)
     newA = self.nodes[0].name_new ("test-name")
     self.generate (0, 10)
@@ -86,8 +97,8 @@ def run_test (self):
     self.firstupdateName (0, "test-name", newA, "test-value")
 
     # Check for disallowed firstupdate when the name is active.
-    newSteal = self.nodes[1].name_new ("node-0")
-    newSteal2 = self.nodes[1].name_new ("node-0")
+    newSteal = self.nodes[1].name_new ("node-0", {"allowExisting": True})
+    newSteal2 = self.nodes[1].name_new ("node-0", {"allowExisting": True})
     self.generate (0, 19)
     self.checkName (1, "node-0", "value-0", 1, False)
     assert_raises_rpc_error (-25, 'this name is already active',
