2 files changed, 31 insertions, 15 deletions

diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 15a1646ffb..36c5f2c5de 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -3427,7 +3427,7 @@ bool CWallet::TopUpKeyPool(unsigned int kpSize)
     return true;
 }
 
-void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal)
+bool CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal)
 {
     nIndex = -1;
     keypool.vchPubKey = CPubKey();
@@ -3438,11 +3438,13 @@ void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRe
             TopUpKeyPool();
 
         bool fReturningInternal = IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT) && fRequestedInternal;
-        std::set<int64_t>& setKeyPool = set_pre_split_keypool.empty() ? (fReturningInternal ? setInternalKeyPool : setExternalKeyPool) : set_pre_split_keypool;
+        bool use_split_keypool = set_pre_split_keypool.empty();
+        std::set<int64_t>& setKeyPool = use_split_keypool ? (fReturningInternal ? setInternalKeyPool : setExternalKeyPool) : set_pre_split_keypool;
 
         // Get the oldest key
-        if(setKeyPool.empty())
-            return;
+        if (setKeyPool.empty()) {
+            return false;
+        }
 
         WalletBatch batch(*database);
 
@@ -3456,14 +3458,17 @@ void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRe
             throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
         }
         // If the key was pre-split keypool, we don't care about what type it is
-        if (set_pre_split_keypool.size() == 0 && keypool.fInternal != fReturningInternal) {
+        if (use_split_keypool && keypool.fInternal != fReturningInternal) {
             throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
         }
+        if (!keypool.vchPubKey.IsValid()) {
+            throw std::runtime_error(std::string(__func__) + ": keypool entry invalid");
+        }
 
-        assert(keypool.vchPubKey.IsValid());
         m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
         LogPrintf("keypool reserve %d\n", nIndex);
     }
+    return true;
 }
 
 void CWallet::KeepKey(int64_t nIndex)
@@ -3496,10 +3501,8 @@ bool CWallet::GetKeyFromPool(CPubKey& result, bool internal)
     CKeyPool keypool;
     {
         LOCK(cs_wallet);
-        int64_t nIndex = 0;
-        ReserveKeyFromKeyPool(nIndex, keypool, internal);
-        if (nIndex == -1)
-        {
+        int64_t nIndex;
+        if (!ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
             if (IsLocked()) return false;
             WalletBatch batch(*database);
             result = GenerateNewKey(batch, internal);
@@ -3701,12 +3704,10 @@ bool CReserveKey::GetReservedKey(CPubKey& pubkey, bool internal)
     if (nIndex == -1)
     {
         CKeyPool keypool;
-        pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal);
-        if (nIndex != -1)
-            vchPubKey = keypool.vchPubKey;
-        else {
+        if (!pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal)) {
             return false;
         }
+        vchPubKey = keypool.vchPubKey;
         fInternal = keypool.fInternal;
     }
     assert(vchPubKey.IsValid());
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index b972bd9e28..f1761b0fcf 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -999,7 +999,22 @@ public:
     bool NewKeyPool();
     size_t KeypoolCountExternalKeys() EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
     bool TopUpKeyPool(unsigned int kpSize = 0);
-    void ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal);
+
+    /**
+     * Reserves a key from the keypool and sets nIndex to its index
+     *
+     * @param[out] nIndex the index of the key in keypool
+     * @param[out] keypool the keypool the key was drawn from, which could be the
+     *     the pre-split pool if present, or the internal or external pool
+     * @param fRequestedInternal true if the caller would like the key drawn
+     *     from the internal keypool, false if external is preferred
+     *
+     * @return true if succeeded, false if failed due to empty keypool
+     * @throws std::runtime_error if keypool read failed, key was invalid,
+     *     was not found in the wallet, or was misclassified in the internal
+     *     or external keypool
+     */
+    bool ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal);
     void KeepKey(int64_t nIndex);
     void ReturnKey(int64_t nIndex, bool fInternal, const CPubKey& pubkey);
     bool GetKeyFromPool(CPubKey &key, bool internal = false);