4 files changed, 30 insertions, 6 deletions
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 5b3b0527b..8ec624254 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -2758,32 +2758,44 @@ void Blockchain::flush_invalid_blocks()
   m_invalid_blocks.clear();
 }
 //------------------------------------------------------------------
-bool Blockchain::have_block(const crypto::hash& id) const
+bool Blockchain::have_block_unlocked(const crypto::hash& id, int *where) const
 {
+  // WARNING: this function does not take m_blockchain_lock, and thus should only call read only
+  // m_db functions which do not depend on one another (ie, no getheight + gethash(height-1), as
+  // well as not accessing class members, even read only (ie, m_invalid_blocks). The caller must
+  // lock if it is otherwise needed.
   LOG_PRINT_L3("Blockchain::" << __func__);
-  CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
   if(m_db->block_exists(id))
   {
     LOG_PRINT_L2("block " << id << " found in main chain");
+    if (where) *where = HAVE_BLOCK_MAIN_CHAIN;
     return true;
   }
 
   if(m_db->get_alt_block(id, NULL, NULL))
   {
     LOG_PRINT_L2("block " << id << " found in alternative chains");
+    if (where) *where = HAVE_BLOCK_ALT_CHAIN;
     return true;
   }
 
   if(m_invalid_blocks.count(id))
   {
     LOG_PRINT_L2("block " << id << " found in m_invalid_blocks");
+    if (where) *where = HAVE_BLOCK_INVALID;
     return true;
   }
 
   return false;
 }
 //------------------------------------------------------------------
+bool Blockchain::have_block(const crypto::hash& id, int *where) const
+{
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+  return have_block_unlocked(id, where);
+}
+//------------------------------------------------------------------
 bool Blockchain::handle_block_to_main_chain(const block& bl, block_verification_context& bvc, bool notify/* = true*/)
 {
     LOG_PRINT_L3("Blockchain::" << __func__);
@@ -4716,6 +4728,8 @@ uint64_t Blockchain::prevalidate_block_hashes(uint64_t height, const std::vector
 
   CHECK_AND_ASSERT_MES(weights.empty() || weights.size() == hashes.size(), 0, "Unexpected weights size");
 
+  CRITICAL_REGION_LOCAL(m_blockchain_lock);
+
   // easy case: height >= hashes
   if (height >= m_blocks_hash_of_hashes.size() * HASH_OF_HASHES_STEP)
     return hashes.size();
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 07238b719..5291f1338 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -377,10 +377,12 @@ namespace cryptonote
      * for a block with the given hash
      *
      * @param id the hash to search for
+     * @param where the type of block, if non NULL
      *
      * @return true if the block is known, else false
      */
-    bool have_block(const crypto::hash& id) const;
+    bool have_block_unlocked(const crypto::hash& id, int *where = NULL) const;
+    bool have_block(const crypto::hash& id, int *where = NULL) const;
 
     /**
      * @brief gets the total number of transactions on the main chain
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index 507c47a51..12125fb9d 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -1625,9 +1625,14 @@ namespace cryptonote
     return m_mempool.get_transactions_count(include_sensitive_txes);
   }
   //-----------------------------------------------------------------------------------------------
-  bool core::have_block(const crypto::hash& id) const
+  bool core::have_block_unlocked(const crypto::hash& id, int *where) const
   {
-    return m_blockchain_storage.have_block(id);
+    return m_blockchain_storage.have_block_unlocked(id, where);
+  }
+  //-----------------------------------------------------------------------------------------------
+  bool core::have_block(const crypto::hash& id, int *where) const
+  {
+    return m_blockchain_storage.have_block(id, where);
   }
   //-----------------------------------------------------------------------------------------------
   bool core::parse_tx_from_blob(transaction& tx, crypto::hash& tx_hash, const blobdata& blob) const
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index 24d0f9e76..8891540a9 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -55,6 +55,8 @@
 PUSH_WARNINGS
 DISABLE_VS_WARNINGS(4355)
 
+enum { HAVE_BLOCK_MAIN_CHAIN, HAVE_BLOCK_ALT_CHAIN, HAVE_BLOCK_INVALID };
+
 namespace cryptonote
 {
    struct test_options {
@@ -543,7 +545,8 @@ namespace cryptonote
       *
       * @note see Blockchain::have_block
       */
-     bool have_block(const crypto::hash& id) const;
+     bool have_block_unlocked(const crypto::hash& id, int *where = NULL) const;
+     bool have_block(const crypto::hash& id, int *where = NULL) const;
 
      /**
       * @copydoc Blockchain::get_short_chain_history