refund from net stake is not allowed to go to cpu stake and vice versa #3180

contracts/eosio.system/delegate_bandwidth.cpp

@@ -63,12 +63,13 @@ namespace eosiosystem {
    struct refund_request {
       account_name  owner;
       time          request_time;
-      eosio::asset  amount;
+      eosio::asset  net_amount;
+      eosio::asset  cpu_amount;
 
       uint64_t  primary_key()const { return owner; }
 
       // explicit serialization macro is not necessary, used here only to improve compilation time
-      EOSLIB_SERIALIZE( refund_request, (owner)(request_time)(amount) )
+      EOSLIB_SERIALIZE( refund_request, (owner)(request_time)(net_amount)(cpu_amount) )
    };
 
    /**
@@ -223,10 +224,10 @@ namespace eosiosystem {
    }
 
    void system_contract::changebw( account_name from, account_name receiver,
-                                   asset stake_net_quantity, asset stake_cpu_quantity, bool transfer )
+                                   const asset stake_net_delta, const asset stake_cpu_delta, bool transfer )
    {
       require_auth( from );
-      eosio_assert( stake_net_quantity != asset(0) || stake_cpu_quantity != asset(0), "should stake non-zero amount" );
+      eosio_assert( stake_net_delta != asset(0) || stake_cpu_delta != asset(0), "should stake non-zero amount" );
 
       account_name source_stake_from = from;
       if ( transfer ) {
@@ -241,14 +242,14 @@ namespace eosiosystem {
             itr = del_tbl.emplace( from, [&]( auto& dbo ){
                   dbo.from          = from;
                   dbo.to            = receiver;
-                  dbo.net_weight    = stake_net_quantity;
-                  dbo.cpu_weight    = stake_cpu_quantity;
+                  dbo.net_weight    = stake_net_delta;
+                  dbo.cpu_weight    = stake_cpu_delta;
                });
          }
          else {
             del_tbl.modify( itr, 0, [&]( auto& dbo ){
-                  dbo.net_weight    += stake_net_quantity;
-                  dbo.cpu_weight    += stake_cpu_quantity;
+                  dbo.net_weight    += stake_net_delta;
+                  dbo.cpu_weight    += stake_cpu_delta;
                });
          }
          eosio_assert( asset(0) <= itr->net_weight, "insufficient staked net bandwidth" );
@@ -265,13 +266,13 @@ namespace eosiosystem {
          if( tot_itr ==  totals_tbl.end() ) {
             tot_itr = totals_tbl.emplace( from, [&]( auto& tot ) {
                   tot.owner = receiver;
-                  tot.net_weight    = stake_net_quantity;
-                  tot.cpu_weight    = stake_cpu_quantity;
+                  tot.net_weight    = stake_net_delta;
+                  tot.cpu_weight    = stake_cpu_delta;
                });
          } else {
             totals_tbl.modify( tot_itr, from == receiver ? from : 0, [&]( auto& tot ) {
-                  tot.net_weight    += stake_net_quantity;
-                  tot.cpu_weight    += stake_cpu_quantity;
+                  tot.net_weight    += stake_net_delta;
+                  tot.cpu_weight    += stake_cpu_delta;
                });
          }
          eosio_assert( asset(0) <= tot_itr->net_weight, "insufficient staked total net bandwidth" );
@@ -284,46 +285,53 @@ namespace eosiosystem {
          }
       } // tot_itr can be invalid, should go out of scope
 
-      // transfer money or schedule a refund
-      asset total_update = stake_net_quantity + stake_cpu_quantity;
-
-      if ( N(eosio) != source_stake_from ) { //for eosio transfer/refund doesn't make sense
+      // create refund or update from existing refund
+      if ( N(eosio) != source_stake_from ) { //for eosio both transfer and refund make no sense
          refunds_table refunds_tbl( _self, from );
          auto req = refunds_tbl.find( from );
 
          //create/update/delete refund
-         asset update_balance = total_update;
+         auto net_balance = stake_net_delta;
+         auto cpu_balance = stake_cpu_delta;
          bool need_deferred_trx = false;
-         if ( req != refunds_tbl.end() ) {
+         if ( req != refunds_tbl.end() ) { //need to update refund
             refunds_tbl.modify( req, 0, [&]( refund_request& r ) {
-                  r.amount -= update_balance;
-                  if ( r.amount < asset(0) ){
-                     update_balance = -r.amount;
-                     r.amount = asset(0);
+                  r.net_amount -= net_balance;
+                  if ( r.net_amount < asset(0) ) {
+                     net_balance = -r.net_amount;
+                     r.net_amount = asset(0);
+                  }
+                  r.cpu_amount -= cpu_balance;
+                  if ( r.cpu_amount < asset(0) ){
+                     cpu_balance = -r.cpu_amount;
+                     r.cpu_amount = asset(0);
                   }
                   r.request_time = now();
                });
-            eosio_assert( asset(0) <= req->amount, "negative refund amount" ); //should never happen
+            eosio_assert( asset(0) <= req->net_amount, "negative net refund amount" ); //should never happen
+            eosio_assert( asset(0) <= req->cpu_amount, "negative cpu refund amount" ); //should never happen
 
-            if ( req->amount == asset(0) ) {
+            if ( req->net_amount == asset(0) && req->cpu_amount == asset(0) ) {
                refunds_tbl.erase( req );
                need_deferred_trx = false;
             } else {
                need_deferred_trx = true;
             }
-         } else if ( update_balance < asset(0) ) {
+         } else if ( net_balance < asset(0) && cpu_balance < asset(0) ) { //need to create refund
             refunds_tbl.emplace( from, [&]( refund_request& r ) {
                   r.owner = from;
-                  r.amount = -total_update;
+                  if ( net_balance < asset(0) ) {
+                     r.net_amount = -net_balance;
+                     net_balance = asset(0);
+                  } // else r.net_amount = 0 by default constructor
+                  if ( cpu_balance < asset(0) ) {
+                     r.cpu_amount = -cpu_balance;
+                     cpu_balance = asset(0);
+                  } // else r.cpu_amount = 0 by default constructor
                   r.request_time = now();
                });
             need_deferred_trx = true;
-         } // else stake increases with no existing row in refunds_tbl -> nothing to do with refunds_tbl
-
-         if ( asset(0) < update_balance ) {
-            INLINE_ACTION_SENDER(eosio::token, transfer)( N(eosio.token), {from,N(active)},
-               { source_stake_from, N(eosio), asset(update_balance), std::string("stake bandwidth") } );
-         }
+         } // else stake increase requested with no existing row in refunds_tbl -> nothing to do with refunds_tbl
 
          if ( need_deferred_trx ) {
             eosio::transaction out;
@@ -333,10 +341,17 @@ namespace eosiosystem {
          } else {
             //cancel_deferred( from );
          }
+
+         auto transfer_amount = net_balance + cpu_balance;
+         if ( asset(0) < transfer_amount ) {
+            INLINE_ACTION_SENDER(eosio::token, transfer)( N(eosio.token), {from,N(active)},
+               { source_stake_from, N(eosio), asset(transfer_amount), std::string("stake bandwidth") } );
+         }
       }
 
       // update voting power
       {
+         asset total_update = stake_net_delta + stake_cpu_delta;
          auto from_voter = _voters.find(from);
          if( from_voter == _voters.end() ) {
             from_voter = _voters.emplace( from, [&]( auto& v ) {
@@ -393,7 +408,7 @@ namespace eosiosystem {
       // consecutive missed blocks.
 
       INLINE_ACTION_SENDER(eosio::token, transfer)( N(eosio.token), {N(eosio),N(active)},
-                                                    { N(eosio), req->owner, req->amount, std::string("unstake") } );
+                                                    { N(eosio), req->owner, req->net_amount + req->cpu_amount, std::string("unstake") } );
 
       refunds_tbl.erase( req );
    }