Replace direct use of 0 with SetNull and IsNull

Replace x=0 with .SetNull(),
x==0 with IsNull(), x!=0 with !IsNull().
Replace uses of uint256(0) with uint256().

1 files changed, 3 insertions, 3 deletions

diff --git a/src/coins.cpp b/src/coins.cpp
index f4599ff39d..ef4f96fdee 100644
--- a/src/coins.cpp
+++ b/src/coins.cpp
@@ -42,7 +42,7 @@ bool CCoins::Spend(uint32_t nPos)
 
 bool CCoinsView::GetCoins(const uint256 &txid, CCoins &coins) const { return false; }
 bool CCoinsView::HaveCoins(const uint256 &txid) const { return false; }
-uint256 CCoinsView::GetBestBlock() const { return uint256(0); }
+uint256 CCoinsView::GetBestBlock() const { return uint256(); }
 bool CCoinsView::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return false; }
 bool CCoinsView::GetStats(CCoinsStats &stats) const { return false; }
 
@@ -57,7 +57,7 @@ bool CCoinsViewBacked::GetStats(CCoinsStats &stats) const { return base->GetStat
 
 CCoinsKeyHasher::CCoinsKeyHasher() : salt(GetRandHash()) {}
 
-CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), hasModifier(false), hashBlock(0) { }
+CCoinsViewCache::CCoinsViewCache(CCoinsView *baseIn) : CCoinsViewBacked(baseIn), hasModifier(false) { }
 
 CCoinsViewCache::~CCoinsViewCache()
 {
@@ -128,7 +128,7 @@ bool CCoinsViewCache::HaveCoins(const uint256 &txid) const {
 }
 
 uint256 CCoinsViewCache::GetBestBlock() const {
-    if (hashBlock == uint256(0))
+    if (hashBlock.IsNull())
         hashBlock = base->GetBestBlock();
     return hashBlock;
 }