Remove access to node globals from wallet-linked code

Remove last few instances of accesses to node global variables from wallet
code. Also remove accesses to node globals from code in policy/policy.cpp that
isn't actually called by wallet code, but does get linked into wallet code.

This is the last change needed to allow bitcoin-wallet tool to be linked
without depending on libbitcoin_server.a, to ensure wallet code doesn't access
node global state and avoid bugs like
https://github.com/bitcoin/bitcoin/pull/15557#discussion_r267735431

2 files changed, 19 insertions, 0 deletions

diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index 13e7848cc6..b61a51b235 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -363,6 +363,12 @@ public:
     {
         return MakeUnique<RpcHandlerImpl>(command);
     }
+    bool rpcEnableDeprecated(const std::string& method) override { return IsDeprecatedRPCEnabled(method); }
+    void rpcRunLater(const std::string& name, std::function<void()> fn, int64_t seconds) override
+    {
+        RPCRunLater(name, std::move(fn), seconds);
+    }
+    int rpcSerializationFlags() override { return RPCSerializationFlags(); }
     void requestMempoolTransactions(Notifications& notifications) override
     {
         LOCK2(::cs_main, ::mempool.cs);
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 3ace5a0ece..17d7b6d8f1 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -57,6 +57,10 @@ class Wallet;
 //!   notifications to the GUI should go away when GUI and wallet can directly
 //!   communicate with each other without going through the node
 //!   (https://github.com/bitcoin/bitcoin/pull/15288#discussion_r253321096).
+//!
+//! * The handleRpc, registerRpcs, rpcEnableDeprecated methods and other RPC
+//!   methods can go away if wallets listen for HTTP requests on their own
+//!   ports instead of registering to handle requests on the node HTTP port.
 class Chain
 {
 public:
@@ -274,6 +278,15 @@ public:
     //! needs to remain valid until Handler is disconnected.
     virtual std::unique_ptr<Handler> handleRpc(const CRPCCommand& command) = 0;
 
+    //! Check if deprecated RPC is enabled.
+    virtual bool rpcEnableDeprecated(const std::string& method) = 0;
+
+    //! Run function after given number of seconds. Cancel any previous calls with same name.
+    virtual void rpcRunLater(const std::string& name, std::function<void()> fn, int64_t seconds) = 0;
+
+    //! Current RPC serialization flags.
+    virtual int rpcSerializationFlags() = 0;
+
     //! Synchronously send TransactionAddedToMempool notifications about all
     //! current mempool transactions to the specified handler and return after
     //! the last one is sent. These notifications aren't coordinated with async