Merge #16227: Refactor CWallet's inheritance chain

93ce4a0b6fb54efb1f424a71dfc09cc33307e5b9 Move WatchOnly stuff from SigningProvider to CWallet (Andrew Chow)
8f5b81e6edae9cb22559545de63f391d97c15701 Remove CCryptoKeyStore and move all of it's functionality into CWallet (Andrew Chow)
37a79a4fccbf6cd65a933594e24e59d36e674653 Move various SigningProviders to signingprovider.{cpp,h} (Andrew Chow)
16f8096e911e4d59292240a17e2d4004f0500b9e Move KeyOriginInfo to its own header file (Andrew Chow)
d9becff4e13da8e182631baa79b9794c03d44434 scripted-diff: rename CBasicKeyStore to FillableSigningProvider (Andrew Chow)
a913e3f2fbeb1352fc66f334d4f5f7332ea89ad7 Move HaveKey static function from keystore to rpcwallet where it is used (Andrew Chow)
c7797ec65544bd23a2e571b2892e1bf512f2a485 Remove CKeyStore and squash into CBasicKeyStore (Andrew Chow)
1b699a5083b435c2b79f3951f94ac9f967d24f6c Add HaveKey and HaveCScript to SigningProvider (Andrew Chow)

Pull request description:

  This PR compresses the `CWallet` chain of inheritance from 5 classes to 3 classes. `CBasicKeyStore` is renamed to `FillableSigningProvider` and some parts of it (the watchonly parts) are moved into `CWallet`. `CKeyStore` and `CCrypoKeyStore` are completely removed. `CKeyStore`'s `Have*` functions are moved into `SigningProvider` and the `Add*` moved into `FillableSigningProvider`, thus allowing it to go away entirely. `CCryptoKeyStore`'s functionality is moved into `CWallet`. The new inheritance chain is:

  ```
  SigningProvider -> FillableSigningProvider -> CWallet
  ```

  `SigningProvider` now is the class the provides keys and scripts and indicates whether keys and scripts are present. `FillableSigningProvider` allows keys and scripts to be added to the signing provider via `Add*` functions. `CWallet` handles all of the watchonly stuff (`AddWatchOnly`, `HaveWatchOnly`, `RemoveWatchOnly` which were previously in `CKeyStore`) and key encryption (previously in `CCryptoKeyStore`).

  Implements the 2nd [prerequisite](https://github.com/bitcoin-core/bitcoin-devwiki/wiki/Wallet-Class-Structure-Changes#cwallet-subclass-stack) from the wallet restructure.

ACKs for top commit:
  Sjors:
    re-ACK 93ce4a0; it keeps `EncryptSecret`, `DecryptSecret` and `DecryptKey` in `wallet/crypter.cpp`, but makes them not static. It improves alphabetical includes, reorders some function definitions, fixes commit message, brings back lost code comment.
  instagibbs:
    utACK https://github.com/bitcoin/bitcoin/pull/16227/commits/93ce4a0b6fb54efb1f424a71dfc09cc33307e5b9

Tree-SHA512: 393dfd0623ad2dac38395eb89b862424318d6072f0b7083c92a0d207fd032c48b284f5f2cb13bc492f34557de350c5fee925da02e47daf011c5c6930a721b6d3

7 files changed, 332 insertions, 128 deletions

diff --git a/src/script/descriptor.h b/src/script/descriptor.h
index af7ae229ca..29915c6c92 100644
--- a/src/script/descriptor.h
+++ b/src/script/descriptor.h
@@ -7,6 +7,7 @@
 
 #include <script/script.h>
 #include <script/sign.h>
+#include <script/signingprovider.h>
 
 #include <vector>
 
diff --git a/src/script/keyorigin.h b/src/script/keyorigin.h
new file mode 100644
index 0000000000..610f233500
--- /dev/null
+++ b/src/script/keyorigin.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_SCRIPT_KEYORIGIN_H
+#define BITCOIN_SCRIPT_KEYORIGIN_H
+
+#include <serialize.h>
+#include <streams.h>
+#include <vector>
+
+struct KeyOriginInfo
+{
+    unsigned char fingerprint[4]; //!< First 32 bits of the Hash160 of the public key at the root of the path
+    std::vector<uint32_t> path;
+
+    friend bool operator==(const KeyOriginInfo& a, const KeyOriginInfo& b)
+    {
+        return std::equal(std::begin(a.fingerprint), std::end(a.fingerprint), std::begin(b.fingerprint)) && a.path == b.path;
+    }
+
+    ADD_SERIALIZE_METHODS;
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action)
+    {
+        READWRITE(fingerprint);
+        READWRITE(path);
+    }
+
+    void clear()
+    {
+        memset(fingerprint, 0, 4);
+        path.clear();
+    }
+};
+
+#endif // BITCOIN_SCRIPT_KEYORIGIN_H
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 5320dc0876..13481af9c5 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -8,6 +8,7 @@
 #include <key.h>
 #include <policy/policy.h>
 #include <primitives/transaction.h>
+#include <script/signingprovider.h>
 #include <script/standard.h>
 #include <uint256.h>
 
@@ -423,22 +424,10 @@ public:
     }
 };
 
-template<typename M, typename K, typename V>
-bool LookupHelper(const M& map, const K& key, V& value)
-{
-    auto it = map.find(key);
-    if (it != map.end()) {
-        value = it->second;
-        return true;
-    }
-    return false;
-}
-
 }
 
 const BaseSignatureCreator& DUMMY_SIGNATURE_CREATOR = DummySignatureCreator(32, 32);
 const BaseSignatureCreator& DUMMY_MAXIMUM_SIGNATURE_CREATOR = DummySignatureCreator(33, 32);
-const SigningProvider& DUMMY_SIGNING_PROVIDER = SigningProvider();
 
 bool IsSolvable(const SigningProvider& provider, const CScript& script)
 {
@@ -459,53 +448,6 @@ bool IsSolvable(const SigningProvider& provider, const CScript& script)
     return false;
 }
 
-bool HidingSigningProvider::GetCScript(const CScriptID& scriptid, CScript& script) const
-{
-    return m_provider->GetCScript(scriptid, script);
-}
-
-bool HidingSigningProvider::GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const
-{
-    return m_provider->GetPubKey(keyid, pubkey);
-}
-
-bool HidingSigningProvider::GetKey(const CKeyID& keyid, CKey& key) const
-{
-    if (m_hide_secret) return false;
-    return m_provider->GetKey(keyid, key);
-}
-
-bool HidingSigningProvider::GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const
-{
-    if (m_hide_origin) return false;
-    return m_provider->GetKeyOrigin(keyid, info);
-}
-
-bool FlatSigningProvider::GetCScript(const CScriptID& scriptid, CScript& script) const { return LookupHelper(scripts, scriptid, script); }
-bool FlatSigningProvider::GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const { return LookupHelper(pubkeys, keyid, pubkey); }
-bool FlatSigningProvider::GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const
-{
-    std::pair<CPubKey, KeyOriginInfo> out;
-    bool ret = LookupHelper(origins, keyid, out);
-    if (ret) info = std::move(out.second);
-    return ret;
-}
-bool FlatSigningProvider::GetKey(const CKeyID& keyid, CKey& key) const { return LookupHelper(keys, keyid, key); }
-
-FlatSigningProvider Merge(const FlatSigningProvider& a, const FlatSigningProvider& b)
-{
-    FlatSigningProvider ret;
-    ret.scripts = a.scripts;
-    ret.scripts.insert(b.scripts.begin(), b.scripts.end());
-    ret.pubkeys = a.pubkeys;
-    ret.pubkeys.insert(b.pubkeys.begin(), b.pubkeys.end());
-    ret.keys = a.keys;
-    ret.keys.insert(b.keys.begin(), b.keys.end());
-    ret.origins = a.origins;
-    ret.origins.insert(b.origins.begin(), b.origins.end());
-    return ret;
-}
-
 bool IsSegWitOutput(const SigningProvider& provider, const CScript& script)
 {
     std::vector<valtype> solutions;
diff --git a/src/script/sign.h b/src/script/sign.h
index e5c0329a61..0e751afd3b 100644
--- a/src/script/sign.h
+++ b/src/script/sign.h
@@ -10,6 +10,7 @@
 #include <hash.h>
 #include <pubkey.h>
 #include <script/interpreter.h>
+#include <script/keyorigin.h>
 #include <streams.h>
 
 class CKey;
@@ -17,77 +18,10 @@ class CKeyID;
 class CScript;
 class CScriptID;
 class CTransaction;
+class SigningProvider;
 
 struct CMutableTransaction;
 
-struct KeyOriginInfo
-{
-    unsigned char fingerprint[4]; //!< First 32 bits of the Hash160 of the public key at the root of the path
-    std::vector<uint32_t> path;
-
-    friend bool operator==(const KeyOriginInfo& a, const KeyOriginInfo& b)
-    {
-        return std::equal(std::begin(a.fingerprint), std::end(a.fingerprint), std::begin(b.fingerprint)) && a.path == b.path;
-    }
-
-    ADD_SERIALIZE_METHODS;
-    template <typename Stream, typename Operation>
-    inline void SerializationOp(Stream& s, Operation ser_action)
-    {
-        READWRITE(fingerprint);
-        READWRITE(path);
-    }
-
-    void clear()
-    {
-        memset(fingerprint, 0, 4);
-        path.clear();
-    }
-};
-
-/** An interface to be implemented by keystores that support signing. */
-class SigningProvider
-{
-public:
-    virtual ~SigningProvider() {}
-    virtual bool GetCScript(const CScriptID &scriptid, CScript& script) const { return false; }
-    virtual bool GetPubKey(const CKeyID &address, CPubKey& pubkey) const { return false; }
-    virtual bool GetKey(const CKeyID &address, CKey& key) const { return false; }
-    virtual bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const { return false; }
-};
-
-extern const SigningProvider& DUMMY_SIGNING_PROVIDER;
-
-class HidingSigningProvider : public SigningProvider
-{
-private:
-    const bool m_hide_secret;
-    const bool m_hide_origin;
-    const SigningProvider* m_provider;
-
-public:
-    HidingSigningProvider(const SigningProvider* provider, bool hide_secret, bool hide_origin) : m_hide_secret(hide_secret), m_hide_origin(hide_origin), m_provider(provider) {}
-    bool GetCScript(const CScriptID& scriptid, CScript& script) const override;
-    bool GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const override;
-    bool GetKey(const CKeyID& keyid, CKey& key) const override;
-    bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override;
-};
-
-struct FlatSigningProvider final : public SigningProvider
-{
-    std::map<CScriptID, CScript> scripts;
-    std::map<CKeyID, CPubKey> pubkeys;
-    std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>> origins;
-    std::map<CKeyID, CKey> keys;
-
-    bool GetCScript(const CScriptID& scriptid, CScript& script) const override;
-    bool GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const override;
-    bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override;
-    bool GetKey(const CKeyID& keyid, CKey& key) const override;
-};
-
-FlatSigningProvider Merge(const FlatSigningProvider& a, const FlatSigningProvider& b);
-
 /** Interface for signature creators. */
 class BaseSignatureCreator {
 public:
diff --git a/src/script/signingprovider.cpp b/src/script/signingprovider.cpp
new file mode 100644
index 0000000000..01757e2f65
--- /dev/null
+++ b/src/script/signingprovider.cpp
@@ -0,0 +1,199 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <script/keyorigin.h>
+#include <script/signingprovider.h>
+#include <script/standard.h>
+
+#include <util/system.h>
+
+const SigningProvider& DUMMY_SIGNING_PROVIDER = SigningProvider();
+
+template<typename M, typename K, typename V>
+bool LookupHelper(const M& map, const K& key, V& value)
+{
+    auto it = map.find(key);
+    if (it != map.end()) {
+        value = it->second;
+        return true;
+    }
+    return false;
+}
+
+bool HidingSigningProvider::GetCScript(const CScriptID& scriptid, CScript& script) const
+{
+    return m_provider->GetCScript(scriptid, script);
+}
+
+bool HidingSigningProvider::GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const
+{
+    return m_provider->GetPubKey(keyid, pubkey);
+}
+
+bool HidingSigningProvider::GetKey(const CKeyID& keyid, CKey& key) const
+{
+    if (m_hide_secret) return false;
+    return m_provider->GetKey(keyid, key);
+}
+
+bool HidingSigningProvider::GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const
+{
+    if (m_hide_origin) return false;
+    return m_provider->GetKeyOrigin(keyid, info);
+}
+
+bool FlatSigningProvider::GetCScript(const CScriptID& scriptid, CScript& script) const { return LookupHelper(scripts, scriptid, script); }
+bool FlatSigningProvider::GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const { return LookupHelper(pubkeys, keyid, pubkey); }
+bool FlatSigningProvider::GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const
+{
+    std::pair<CPubKey, KeyOriginInfo> out;
+    bool ret = LookupHelper(origins, keyid, out);
+    if (ret) info = std::move(out.second);
+    return ret;
+}
+bool FlatSigningProvider::GetKey(const CKeyID& keyid, CKey& key) const { return LookupHelper(keys, keyid, key); }
+
+FlatSigningProvider Merge(const FlatSigningProvider& a, const FlatSigningProvider& b)
+{
+    FlatSigningProvider ret;
+    ret.scripts = a.scripts;
+    ret.scripts.insert(b.scripts.begin(), b.scripts.end());
+    ret.pubkeys = a.pubkeys;
+    ret.pubkeys.insert(b.pubkeys.begin(), b.pubkeys.end());
+    ret.keys = a.keys;
+    ret.keys.insert(b.keys.begin(), b.keys.end());
+    ret.origins = a.origins;
+    ret.origins.insert(b.origins.begin(), b.origins.end());
+    return ret;
+}
+
+void FillableSigningProvider::ImplicitlyLearnRelatedKeyScripts(const CPubKey& pubkey)
+{
+    AssertLockHeld(cs_KeyStore);
+    CKeyID key_id = pubkey.GetID();
+    // This adds the redeemscripts necessary to detect P2WPKH and P2SH-P2WPKH
+    // outputs. Technically P2WPKH outputs don't have a redeemscript to be
+    // spent. However, our current IsMine logic requires the corresponding
+    // P2SH-P2WPKH redeemscript to be present in the wallet in order to accept
+    // payment even to P2WPKH outputs.
+    // Also note that having superfluous scripts in the keystore never hurts.
+    // They're only used to guide recursion in signing and IsMine logic - if
+    // a script is present but we can't do anything with it, it has no effect.
+    // "Implicitly" refers to fact that scripts are derived automatically from
+    // existing keys, and are present in memory, even without being explicitly
+    // loaded (e.g. from a file).
+    if (pubkey.IsCompressed()) {
+        CScript script = GetScriptForDestination(WitnessV0KeyHash(key_id));
+        // This does not use AddCScript, as it may be overridden.
+        CScriptID id(script);
+        mapScripts[id] = std::move(script);
+    }
+}
+
+bool FillableSigningProvider::GetPubKey(const CKeyID &address, CPubKey &vchPubKeyOut) const
+{
+    CKey key;
+    if (!GetKey(address, key)) {
+        return false;
+    }
+    vchPubKeyOut = key.GetPubKey();
+    return true;
+}
+
+bool FillableSigningProvider::AddKeyPubKey(const CKey& key, const CPubKey &pubkey)
+{
+    LOCK(cs_KeyStore);
+    mapKeys[pubkey.GetID()] = key;
+    ImplicitlyLearnRelatedKeyScripts(pubkey);
+    return true;
+}
+
+bool FillableSigningProvider::HaveKey(const CKeyID &address) const
+{
+    LOCK(cs_KeyStore);
+    return mapKeys.count(address) > 0;
+}
+
+std::set<CKeyID> FillableSigningProvider::GetKeys() const
+{
+    LOCK(cs_KeyStore);
+    std::set<CKeyID> set_address;
+    for (const auto& mi : mapKeys) {
+        set_address.insert(mi.first);
+    }
+    return set_address;
+}
+
+bool FillableSigningProvider::GetKey(const CKeyID &address, CKey &keyOut) const
+{
+    LOCK(cs_KeyStore);
+    KeyMap::const_iterator mi = mapKeys.find(address);
+    if (mi != mapKeys.end()) {
+        keyOut = mi->second;
+        return true;
+    }
+    return false;
+}
+
+bool FillableSigningProvider::AddCScript(const CScript& redeemScript)
+{
+    if (redeemScript.size() > MAX_SCRIPT_ELEMENT_SIZE)
+        return error("FillableSigningProvider::AddCScript(): redeemScripts > %i bytes are invalid", MAX_SCRIPT_ELEMENT_SIZE);
+
+    LOCK(cs_KeyStore);
+    mapScripts[CScriptID(redeemScript)] = redeemScript;
+    return true;
+}
+
+bool FillableSigningProvider::HaveCScript(const CScriptID& hash) const
+{
+    LOCK(cs_KeyStore);
+    return mapScripts.count(hash) > 0;
+}
+
+std::set<CScriptID> FillableSigningProvider::GetCScripts() const
+{
+    LOCK(cs_KeyStore);
+    std::set<CScriptID> set_script;
+    for (const auto& mi : mapScripts) {
+        set_script.insert(mi.first);
+    }
+    return set_script;
+}
+
+bool FillableSigningProvider::GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const
+{
+    LOCK(cs_KeyStore);
+    ScriptMap::const_iterator mi = mapScripts.find(hash);
+    if (mi != mapScripts.end())
+    {
+        redeemScriptOut = (*mi).second;
+        return true;
+    }
+    return false;
+}
+
+CKeyID GetKeyForDestination(const SigningProvider& store, const CTxDestination& dest)
+{
+    // Only supports destinations which map to single public keys, i.e. P2PKH,
+    // P2WPKH, and P2SH-P2WPKH.
+    if (auto id = boost::get<PKHash>(&dest)) {
+        return CKeyID(*id);
+    }
+    if (auto witness_id = boost::get<WitnessV0KeyHash>(&dest)) {
+        return CKeyID(*witness_id);
+    }
+    if (auto script_hash = boost::get<ScriptHash>(&dest)) {
+        CScript script;
+        CScriptID script_id(*script_hash);
+        CTxDestination inner_dest;
+        if (store.GetCScript(script_id, script) && ExtractDestination(script, inner_dest)) {
+            if (auto inner_witness_id = boost::get<WitnessV0KeyHash>(&inner_dest)) {
+                return CKeyID(*inner_witness_id);
+            }
+        }
+    }
+    return CKeyID();
+}
diff --git a/src/script/signingprovider.h b/src/script/signingprovider.h
new file mode 100644
index 0000000000..4eec2311d4
--- /dev/null
+++ b/src/script/signingprovider.h
@@ -0,0 +1,92 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_SCRIPT_SIGNINGPROVIDER_H
+#define BITCOIN_SCRIPT_SIGNINGPROVIDER_H
+
+#include <key.h>
+#include <pubkey.h>
+#include <script/script.h>
+#include <script/standard.h>
+#include <sync.h>
+
+struct KeyOriginInfo;
+
+/** An interface to be implemented by keystores that support signing. */
+class SigningProvider
+{
+public:
+    virtual ~SigningProvider() {}
+    virtual bool GetCScript(const CScriptID &scriptid, CScript& script) const { return false; }
+    virtual bool HaveCScript(const CScriptID &scriptid) const { return false; }
+    virtual bool GetPubKey(const CKeyID &address, CPubKey& pubkey) const { return false; }
+    virtual bool GetKey(const CKeyID &address, CKey& key) const { return false; }
+    virtual bool HaveKey(const CKeyID &address) const { return false; }
+    virtual bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const { return false; }
+};
+
+extern const SigningProvider& DUMMY_SIGNING_PROVIDER;
+
+class HidingSigningProvider : public SigningProvider
+{
+private:
+    const bool m_hide_secret;
+    const bool m_hide_origin;
+    const SigningProvider* m_provider;
+
+public:
+    HidingSigningProvider(const SigningProvider* provider, bool hide_secret, bool hide_origin) : m_hide_secret(hide_secret), m_hide_origin(hide_origin), m_provider(provider) {}
+    bool GetCScript(const CScriptID& scriptid, CScript& script) const override;
+    bool GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const override;
+    bool GetKey(const CKeyID& keyid, CKey& key) const override;
+    bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override;
+};
+
+struct FlatSigningProvider final : public SigningProvider
+{
+    std::map<CScriptID, CScript> scripts;
+    std::map<CKeyID, CPubKey> pubkeys;
+    std::map<CKeyID, std::pair<CPubKey, KeyOriginInfo>> origins;
+    std::map<CKeyID, CKey> keys;
+
+    bool GetCScript(const CScriptID& scriptid, CScript& script) const override;
+    bool GetPubKey(const CKeyID& keyid, CPubKey& pubkey) const override;
+    bool GetKeyOrigin(const CKeyID& keyid, KeyOriginInfo& info) const override;
+    bool GetKey(const CKeyID& keyid, CKey& key) const override;
+};
+
+FlatSigningProvider Merge(const FlatSigningProvider& a, const FlatSigningProvider& b);
+
+/** Fillable signing provider that keeps keys in an address->secret map */
+class FillableSigningProvider : public SigningProvider
+{
+protected:
+    mutable CCriticalSection cs_KeyStore;
+
+    using KeyMap = std::map<CKeyID, CKey>;
+    using ScriptMap = std::map<CScriptID, CScript>;
+
+    KeyMap mapKeys GUARDED_BY(cs_KeyStore);
+    ScriptMap mapScripts GUARDED_BY(cs_KeyStore);
+
+    void ImplicitlyLearnRelatedKeyScripts(const CPubKey& pubkey) EXCLUSIVE_LOCKS_REQUIRED(cs_KeyStore);
+
+public:
+    virtual bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey);
+    virtual bool AddKey(const CKey &key) { return AddKeyPubKey(key, key.GetPubKey()); }
+    virtual bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const override;
+    virtual bool HaveKey(const CKeyID &address) const override;
+    virtual std::set<CKeyID> GetKeys() const;
+    virtual bool GetKey(const CKeyID &address, CKey &keyOut) const override;
+    virtual bool AddCScript(const CScript& redeemScript);
+    virtual bool HaveCScript(const CScriptID &hash) const override;
+    virtual std::set<CScriptID> GetCScripts() const;
+    virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const override;
+};
+
+/** Return the CKeyID of the key involved in a script (if there is a unique one). */
+CKeyID GetKeyForDestination(const SigningProvider& store, const CTxDestination& dest);
+
+#endif // BITCOIN_SCRIPT_SIGNINGPROVIDER_H
diff --git a/src/script/standard.cpp b/src/script/standard.cpp
index b7d6cd925c..fc6898f444 100644
--- a/src/script/standard.cpp
+++ b/src/script/standard.cpp
@@ -9,7 +9,6 @@
 #include <pubkey.h>
 #include <script/script.h>
 
-
 typedef std::vector<unsigned char> valtype;
 
 bool fAcceptDatacarrier = DEFAULT_ACCEPT_DATACARRIER;