node: sort m_dirty_blockindex by block hash

This avoids non-determinism since memory addresses change between
runs for a single input.

Author: Crypt-iQ

src/node/blockstorage.cpp

@@ -180,6 +180,11 @@ bool CBlockIndexHeightOnlyComparator::operator()(const CBlockIndex* pa, const CB
     return pa->nHeight < pb->nHeight;
 }
 
+bool CBlockIndexBlockHashComparator::operator()(const CBlockIndex* pa, const CBlockIndex* pb) const
+{
+    return UintToArith256(pa->GetBlockHash()) < UintToArith256(pb->GetBlockHash());
+}
+
 std::vector<CBlockIndex*> BlockManager::GetAllBlockIndices()
 {
     AssertLockHeld(cs_main);
@@ -488,7 +493,7 @@ bool BlockManager::WriteBlockIndexDB()
     }
     std::vector<const CBlockIndex*> vBlocks;
     vBlocks.reserve(m_dirty_blockindex.size());
-    for (std::set<CBlockIndex*>::iterator it = m_dirty_blockindex.begin(); it != m_dirty_blockindex.end();) {
+    for (std::set<CBlockIndex*, CBlockIndexBlockHashComparator>::iterator it = m_dirty_blockindex.begin(); it != m_dirty_blockindex.end();) {
         vBlocks.push_back(*it);
         m_dirty_blockindex.erase(it++);
     }

src/node/blockstorage.h

@@ -95,6 +95,10 @@ struct CBlockIndexHeightOnlyComparator {
     bool operator()(const CBlockIndex* pa, const CBlockIndex* pb) const;
 };
 
+struct CBlockIndexBlockHashComparator {
+    bool operator()(const CBlockIndex* pa, const CBlockIndex* pb) const;
+};
+
 struct PruneLockInfo {
     int height_first{std::numeric_limits<int>::max()}; //! Height of earliest block that should be kept and not pruned
 };
@@ -238,7 +242,7 @@ class BlockManager
     const Obfuscation m_obfuscation;
 
     /** Dirty block index entries. */
-    std::set<CBlockIndex*> m_dirty_blockindex;
+    std::set<CBlockIndex*, CBlockIndexBlockHashComparator> m_dirty_blockindex;
 
     /** Dirty block file entries. */
     std::set<int> m_dirty_fileinfo;