Increase multisign test coverage

src/test/app/MultiSign_test.cpp

@@ -773,7 +773,7 @@ public:
         // R1: The regular key can be removed if there's a signer list.
         env(regkey (alice, disabled), sig(alie));
 
-        // L0; A lone signer list cannot be removed.
+        // L0: A lone signer list cannot be removed.
         auto const baseFee = env.current()->fees().base;
         env(signers(alice, jtx::none), msig(bogie),
             fee(2 * baseFee), ter(tecNO_ALTERNATIVE_KEY));
@@ -1068,6 +1068,71 @@ public:
         env(noop(alice), msig(becky, demon), fee(3 * baseFee), ter(tefNOT_MULTI_SIGNING));
     }
 
+    void test_multisigningMultisigner()
+    {
+        // Set up a signer list where one of the signers has both the
+        // master disabled and no regular key (because that signer is
+        // exclusively multisigning).  That signer should no longer be
+        // able to successfully sign the signer list.
+
+        using namespace jtx;
+        Env env (*this);
+        Account const alice {"alice", KeyType::ed25519};
+        Account const becky {"becky", KeyType::secp256k1};
+        env.fund (XRP(1000), alice, becky);
+        env.close();
+
+        // alice sets up a signer list with becky as a signer.
+        env (signers (alice, 1, {{becky, 1}}));
+        env.close();
+
+        // becky sets up her signer list.
+        env (signers (becky, 1, {{bogie, 1}, {demon, 1}}));
+        env.close();
+
+        // Because becky has not (yet) disabled her master key, she can
+        // multisign a transaction for alice.
+        auto const baseFee = env.current()->fees().base;
+        env (noop (alice), msig (becky), fee (2 * baseFee));
+        env.close();
+
+        // Now becky disables her master key.
+        env (fset (becky, asfDisableMaster));
+        env.close();
+
+        // Since becky's master key is disabled she can no longer
+        // multisign for alice.
+        env (noop (alice), msig (becky), fee (2 * baseFee),
+            ter (tefMASTER_DISABLED));
+        env.close();
+
+        // Becky cannot 2-level multisign for alice.  2-level multisigning
+        // is not supported.
+        env (noop (alice), msig (msig::Reg {becky, bogie}), fee (2 * baseFee),
+            ter (tefBAD_SIGNATURE));
+        env.close();
+
+        // Verify that becky cannot sign with a regular key that she has
+        // not yet enabled.
+        Account const beck {"beck", KeyType::ed25519};
+        env (noop (alice), msig (msig::Reg {becky, beck}), fee (2 * baseFee),
+            ter (tefBAD_SIGNATURE));
+        env.close();
+
+        // Once becky gives herself the regular key, she can sign for alice
+        // using that regular key.
+        env (regkey (becky, beck), msig (demon), fee (2 * baseFee));
+        env.close();
+
+        env (noop (alice), msig (msig::Reg {becky, beck}), fee (2 * baseFee));
+        env.close();
+
+        // The presence of becky's regular key does not influence whether she
+        // can 2-level multisign; it still won't work.
+        env (noop (alice), msig (msig::Reg {becky, demon}), fee (2 * baseFee),
+            ter (tefBAD_SIGNATURE));
+        env.close();
+    }
 
     void run() override
     {
@@ -1086,6 +1151,7 @@ public:
         test_txTypes();
         test_badSignatureText();
         test_noMultiSigners();
+        test_multisigningMultisigner();
     }
 };