rpc: add "warnings" field to RPCs {create,load,unload,restore}wallet

This new "warnings" field is a JSON array of strings intended to replace the
"warning" string field in these four RPCs, to better handle returning multiple
warning messages and for consistency with other wallet RPCs.

src/rpc/util.cpp

@@ -1175,8 +1175,25 @@ UniValue GetServicesNames(ServiceFlags services)
     return servicesNames;
 }
 
+/** Convert a vector of bilingual strings to a UniValue::VARR containing their original untranslated values. */
+[[nodiscard]] static UniValue BilingualStringsToUniValue(const std::vector<bilingual_str>& bilingual_strings)
+{
+    CHECK_NONFATAL(!bilingual_strings.empty());
+    UniValue result{UniValue::VARR};
+    for (const auto& s : bilingual_strings) {
+        result.push_back(s.original);
+    }
+    return result;
+}
+
 void PushWarnings(const UniValue& warnings, UniValue& obj)
 {
     if (warnings.empty()) return;
     obj.pushKV("warnings", warnings);
 }
+
+void PushWarnings(const std::vector<bilingual_str>& warnings, UniValue& obj)
+{
+    if (warnings.empty()) return;
+    obj.pushKV("warnings", BilingualStringsToUniValue(warnings));
+}

src/rpc/util.h

@@ -388,5 +388,6 @@ private:
  * @param[out] obj      UniValue object to push the warnings array object to.
  */
 void PushWarnings(const UniValue& warnings, UniValue& obj);
+void PushWarnings(const std::vector<bilingual_str>& warnings, UniValue& obj);
 
 #endif // BITCOIN_RPC_UTIL_H

src/wallet/rpc/backup.cpp

@@ -1904,6 +1904,10 @@ RPCHelpMan restorewallet()
             {
                 {RPCResult::Type::STR, "name", "The wallet name if restored successfully."},
                 {RPCResult::Type::STR, "warning", "Warning messages, if any, related to restoring the wallet. Multiple messages will be delimited by newlines."},
+                {RPCResult::Type::ARR, "warnings", /*optional=*/true, "Warning messages, if any, related to restoring the wallet.",
+                {
+                    {RPCResult::Type::STR, "", ""},
+                }},
             }
         },
         RPCExamples{
@@ -1934,6 +1938,7 @@ RPCHelpMan restorewallet()
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
+    PushWarnings(warnings, obj);
 
     return obj;
 

src/wallet/rpc/wallet.cpp

@@ -208,6 +208,10 @@ static RPCHelpMan loadwallet()
                     {
                         {RPCResult::Type::STR, "name", "The wallet name if loaded successfully."},
                         {RPCResult::Type::STR, "warning", "Warning messages, if any, related to loading the wallet. Multiple messages will be delimited by newlines."},
+                        {RPCResult::Type::ARR, "warnings", /*optional=*/true, "Warning messages, if any, related to loading the wallet.",
+                        {
+                            {RPCResult::Type::STR, "", ""},
+                        }},
                     }
                 },
                 RPCExamples{
@@ -241,6 +245,7 @@ static RPCHelpMan loadwallet()
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
+    PushWarnings(warnings, obj);
 
     return obj;
 },
@@ -336,6 +341,10 @@ static RPCHelpMan createwallet()
             {
                 {RPCResult::Type::STR, "name", "The wallet name if created successfully. If the wallet was created using a full path, the wallet_name will be the full path."},
                 {RPCResult::Type::STR, "warning", "Warning messages, if any, related to creating the wallet. Multiple messages will be delimited by newlines."},
+                {RPCResult::Type::ARR, "warnings", /*optional=*/true, "Warning messages, if any, related to creating the wallet.",
+                {
+                    {RPCResult::Type::STR, "", ""},
+                }},
             }
         },
         RPCExamples{
@@ -406,6 +415,7 @@ static RPCHelpMan createwallet()
     UniValue obj(UniValue::VOBJ);
     obj.pushKV("name", wallet->GetName());
     obj.pushKV("warning", Join(warnings, Untranslated("\n")).original);
+    PushWarnings(warnings, obj);
 
     return obj;
 },
@@ -423,6 +433,10 @@ static RPCHelpMan unloadwallet()
                 },
                 RPCResult{RPCResult::Type::OBJ, "", "", {
                     {RPCResult::Type::STR, "warning", "Warning messages, if any, related to unloading the wallet. Multiple messages will be delimited by newlines."},
+                    {RPCResult::Type::ARR, "warnings", /*optional=*/true, "Warning messages, if any, related to unloading the wallet.",
+                    {
+                        {RPCResult::Type::STR, "", ""},
+                    }},
                 }},
                 RPCExamples{
                     HelpExampleCli("unloadwallet", "wallet_name")
@@ -465,6 +479,8 @@ static RPCHelpMan unloadwallet()
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("warning", Join(warnings, Untranslated("\n")).original);
+    PushWarnings(warnings, result);
+
     return result;
 },
     };