wallet2: don't throw when spent amount is inconsistent

src/wallet/wallet2.cpp

@@ -1313,11 +1313,21 @@ void wallet2::process_new_transaction(const crypto::hash &txid, const cryptonote
       uint64_t amount = boost::get<cryptonote::txin_to_key>(in).amount;
       if (amount > 0)
       {
-        THROW_WALLET_EXCEPTION_IF(amount != td.amount(), error::wallet_internal_error,
-            std::string("Inconsistent amount in tx input: got ") + print_money(amount) +
-            std::string(", expected ") + print_money(td.amount()));
+        if(amount != td.amount())
+        {
+          MERROR("Inconsistent amount in tx input: got " << print_money(amount) <<
+            ", expected " << print_money(td.amount()));
+          // this means:
+          //   1) the same output pub key was used as destination multiple times,
+          //   2) the wallet set the highest amount among them to transfer_details::m_amount, and
+          //   3) the wallet somehow spent that output with an amount smaller than the above amount, causing inconsistency
+          td.m_amount = amount;
+        }
+      }
+      else
+      {
+        amount = td.amount();
       }
-      amount = td.amount();
       tx_money_spent_in_ins += amount;
       if (subaddr_account && *subaddr_account != td.m_subaddr_index.major)
         LOG_ERROR("spent funds are from different subaddress accounts; count of incoming/outgoing payments will be incorrect");