Merge pull request #3163 from sipa/allunspendable

Generalize the remove-outputs check for fully-prunable transactions.

src/core.h

@@ -421,6 +421,9 @@ public:
 
     // equality test
     friend bool operator==(const CCoins &a, const CCoins &b) {
+         // Empty CCoins objects are always equal.
+         if (a.IsPruned() && b.IsPruned())
+             return true;
          return a.fCoinBase == b.fCoinBase &&
                 a.nHeight == b.nHeight &&
                 a.nVersion == b.nVersion &&

src/main.cpp

@@ -1750,12 +1750,12 @@ bool DisconnectBlock(CBlock& block, CValidationState& state, CBlockIndex* pindex
         const CTransaction &tx = block.vtx[i];
         uint256 hash = tx.GetHash();
 
-        // check that all outputs are available
-        if (!view.HaveCoins(hash)) {
-            fClean = fClean && error("DisconnectBlock() : outputs still spent? database corrupted");
-            view.SetCoins(hash, CCoins());
-        }
-        CCoins &outs = view.GetCoins(hash);
+        // Check that all outputs are available and match the outputs in the block itself
+        // exactly. Note that transactions with only provably unspendable outputs won't
+        // have outputs available even in the block itself, so we handle that case
+        // specially with outsEmpty.
+        CCoins outsEmpty;
+        CCoins &outs = view.HaveCoins(hash) ? view.GetCoins(hash) : outsEmpty;
         outs.ClearUnspendable();
 
         CCoins outsBlock = CCoins(tx, pindex->nHeight);