rpc: Make name_show take option for whether to error on expired names

Author: yanmaani

src/rpc/names.cpp

@@ -437,13 +437,15 @@ namespace
 UniValue
 name_show (const JSONRPCRequest& request)
 {
-  bool allow_expired = DEFAULT_ALLOWEXPIRED;
+  bool allow_expired_default = DEFAULT_ALLOWEXPIRED;
 
   NameOptionsHelp optHelp;
   optHelp
       .withNameEncoding ()
       .withValueEncoding ()
-      .withByHash ();
+      .withByHash ()
+      .withArg ("allowExpired", RPCArg::Type::BOOL, allow_expired_default ? "true" : "false",
+                "Whether to throw error for expired names");
 
   RPCHelpMan ("name_show",
       "\nLooks up the current data for the given name.  Fails if the name doesn't exist.\n",
@@ -456,6 +458,7 @@ name_show (const JSONRPCRequest& request)
         .finish (),
       RPCExamples {
           HelpExampleCli ("name_show", "\"myname\"")
+        + HelpExampleCli ("name_show", R"("myname" '{"allowExpired": false}')")
         + HelpExampleRpc ("name_show", "\"myname\"")
       }
   ).Check (request);
@@ -470,6 +473,17 @@ name_show (const JSONRPCRequest& request)
   if (request.params.size () >= 2)
     options = request.params[1].get_obj ();
 
+  /* Parse and interpret the name_show-specific options.  */
+  RPCTypeCheckObj(options,
+    {
+      {"allowExpired", UniValueType(UniValue::VBOOL)},
+    },
+    true, false);
+
+  bool allow_expired = allow_expired_default;
+  if (options.exists("allowExpired"))
+    allow_expired = options["allowExpired"].get_bool();
+
   const valtype name = GetNameForLookup (request.params[0], options);
 
   CNameData data;
@@ -488,11 +502,12 @@ name_show (const JSONRPCRequest& request)
   UniValue name_object = getNameInfo(options, name, data, wallet);
   assert(!name_object["expired"].isNull());
   const bool is_expired = name_object["expired"].get_bool();
-  if (is_expired && !allow_expired) {
+  if (is_expired && !allow_expired)
+    {
       std::ostringstream msg;
       msg << "name not found: " << EncodeNameForMessage(name);
       throw JSONRPCError(RPC_WALLET_ERROR, msg.str());
-  }
+    }
   return name_object;
 }