fix: Return objectNotFound for a non-existent book_offers domain

API-CHANGELOG.md

@@ -53,6 +53,7 @@ This section contains changes targeting a future version.
 - `submit`: The `fail_hard` field now returns an error if the value is not a boolean. [#6529](https://github.com/XRPLF/rippled/pull/6529)
 - `subscribe`: The `taker` field in the `books` array now returns `actMalformed` instead of `badIssuer` if the value is not a valid account. [#6529](https://github.com/XRPLF/rippled/pull/6529)
 - Fixed a bug in `Forwarded` HTTP header parsing where the extracted IP address could be incorrect when no comma or semicolon delimiter follows the address. This could cause the server to misidentify a client's IP address when operating behind a reverse proxy. [#6529](https://github.com/XRPLF/rippled/pull/6529)
+- `book_offers`: The `domain` field now returns `objectNotFound` if the specified permissioned domain does not exist in the ledger, instead of silently returning an empty `offers` array. [#7963](https://github.com/XRPLF/rippled/issues/7963)
 
 ## XRP Ledger server version 3.1.0
 

src/test/rpc/Book_test.cpp

@@ -1532,6 +1532,38 @@ class Book_test : public beast::unit_test::Suite
             BEAST_EXPECT(jrr[jss::error] == "domainMalformed");
             BEAST_EXPECT(jrr[jss::error_message] == "Unable to parse domain.");
         }
+
+        // Well-formed domain that does not exist in the ledger.
+        {
+            json::Value jvParams;
+            jvParams[jss::ledger_index] = "validated";
+            jvParams[jss::taker_pays][jss::currency] = "USD";
+            jvParams[jss::taker_pays][jss::issuer] = gw.human();
+            jvParams[jss::taker_gets][jss::currency] = "EUR";
+            jvParams[jss::taker_gets][jss::issuer] = gw.human();
+            jvParams[jss::domain] = std::string(64, 'A');
+            auto const jrr = env.rpc("json", "book_offers", to_string(jvParams))[jss::result];
+            BEAST_EXPECT(jrr[jss::error] == "objectNotFound");
+            BEAST_EXPECT(jrr[jss::error_message] == "Domain not found.");
+        }
+
+        // An all-zero domain is well-formed hex but can never name an object.
+        // Both ledger views are covered: a validated ledger reaches
+        // Ledger::read, which treats a zero key as UNREACHABLE, so dropping
+        // the isZero() guard in doBookOffers aborts on this case.
+        for (auto const* ledgerIndex : {"validated", "current"})
+        {
+            json::Value jvParams;
+            jvParams[jss::ledger_index] = ledgerIndex;
+            jvParams[jss::taker_pays][jss::currency] = "USD";
+            jvParams[jss::taker_pays][jss::issuer] = gw.human();
+            jvParams[jss::taker_gets][jss::currency] = "EUR";
+            jvParams[jss::taker_gets][jss::issuer] = gw.human();
+            jvParams[jss::domain] = std::string(64, '0');
+            auto const jrr = env.rpc("json", "book_offers", to_string(jvParams))[jss::result];
+            BEAST_EXPECT(jrr[jss::error] == "objectNotFound");
+            BEAST_EXPECT(jrr[jss::error_message] == "Domain not found.");
+        }
     }
 
     void
@@ -1662,6 +1694,22 @@ class Book_test : public beast::unit_test::Suite
             checkBookOffers(jrr);
         }
 
+        // book_offers: an unknown domain is rejected rather than silently
+        // returning an empty book
+        {
+            json::Value jvParams;
+            jvParams[jss::taker] = env.master.human();
+            jvParams[jss::taker_pays][jss::currency] = "XRP";
+            jvParams[jss::ledger_index] = "validated";
+            jvParams[jss::taker_gets][jss::currency] = "USD";
+            jvParams[jss::taker_gets][jss::issuer] = gw.human();
+            jvParams[jss::domain] = std::string(64, 'A');
+
+            auto const jrr = env.rpc("json", "book_offers", to_string(jvParams))[jss::result];
+            BEAST_EXPECT(jrr[jss::error] == "objectNotFound");
+            BEAST_EXPECT(jrr[jss::error_message] == "Domain not found.");
+        }
+
         // subscribe to domain book should return domain offer
         {
             json::Value books;

src/xrpld/rpc/handlers/orderbook/BookOffers.cpp

@@ -15,6 +15,7 @@
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/Book.h>
 #include <xrpl/protocol/ErrorCodes.h>
+#include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/Issue.h>
 #include <xrpl/protocol/RPCErr.h>
 #include <xrpl/protocol/UintTypes.h>
@@ -232,6 +233,16 @@ doBookOffers(RPC::JsonContext& context)
             return RPC::makeError(RpcDomainMalformed, "Unable to parse domain.");
         }
 
+        // A PermissionedDomain's DomainID is its ledger key, so the domain
+        // exists only if that entry is present. `read` is used rather than
+        // `exists` because the caller supplies the raw key: `exists` does not
+        // check the entry type, so the index of any unrelated object would
+        // pass. The all-zero key is well-formed hex but can never name a real
+        // object, and `Ledger::read` treats it as UNREACHABLE, so it must be
+        // rejected before reaching the view.
+        if (num.isZero() || !lpLedger->read(keylet::permissionedDomain(num)))
+            return RPC::makeError(RpcObjectNotFound, "Domain not found.");
+
         domain = num;
     }