fix bad block generation for too many new accounts in full blocks

Author: CoinFuMasterShifu

src/node/block/body/generator.cpp

@@ -133,27 +133,30 @@ BodyContainer BlockGenerator::gen_block(NonzeroHeight height,
         throw std::runtime_error("Too many payments");
     }
 
-    // filter valid payments to survive self send
-    std::vector<TransferTxExchangeMessage> validTransfers;
-    for (auto& pmsg : transfers) {
-        if (nas.getId(pmsg.toAddr, true).value() == pmsg.from_id()) {
-            // This should not be possible because self sending transactions
-            // are detected on entering mempool.
-            spdlog::warn("Impossible self send detected.");
-            continue;
-        }
-        validTransfers.push_back(pmsg);
-    }
 
     TransferSection trs;
-    for (auto& pmsg : validTransfers) {
+    for (auto& pmsg : transfers) {
         size_t size { 10 + nas.binarysize() + RewardSection::binary_size + trs.binarysize() };
         assert(size <= MAXBLOCKSIZE);
         size_t remaining = MAXBLOCKSIZE - size;
         if (remaining < 99)
             break;
         bool allowNewAddress { remaining >= 99 + 20 };
         auto toId = nas.getId(pmsg.toAddr, allowNewAddress);
+
+        // filter out invalid self send 
+        if (toId == pmsg.from_id()) {
+            // This should not be possible because self sending transactions
+            // are detected on entering mempool.
+            spdlog::warn("Impossible self send detected.");
+            // we can continue because nas.getId only assigns a new id to an address if that address
+            // has not existed before and this cannot happen for toId == pmsg.from_id() because in this case
+            // the sender must have positive balance (there are no zero value transactions) and therefore
+            // has existed in the chain before.
+            // => we know that  nas.getId did not assign a new account id to pmsg.toAddr so we can continue without
+            // violating block policy that every account Id must be referred.
+            continue;
+        }
         if (!toId)
             break;
 

src/shared/src/general/errors.hpp

@@ -98,9 +98,9 @@
     XX(100, EMSGINTEGRITY, "message integrity check failed")            \
     XX(101, EADDRNOTFOUND, "address not found")                         \
     XX(102, EADDRIDNOTFOUND, "address id not found")                    \
-    XX(103, EIDPOLICY2, "block transaction id policy violated")         \
-    XX(104, EIDPOLICY3, "block transaction id policy violated")         \
-    XX(105, EIDPOLICY4, "block transaction id policy violated")         \
+    XX(103, EIDPOLICY2, "block transaction id policy violated 2")       \
+    XX(104, EIDPOLICY3, "block transaction id policy violated 3")       \
+    XX(105, EIDPOLICY4, "block transaction id policy violated 4")       \
     XX(198, EBATCHSIZE2, "invalid batch size")                          \
     XX(199, EBATCHSIZE3, "invalid batch size")                          \
     XX(200, EINV_HEX, "cannot parse hexadecimal input")                 \