remove unused (but reserved) fields in eosiosystem::voter_info from ABI; add...

remove unused (but reserved) fields in eosiosystem::voter_info from ABI; add clarifying comments to system_contract::buyram fee logic

contracts/eosio.system/delegate_bandwidth.cpp

@@ -108,9 +108,14 @@ namespace eosiosystem {
       eosio_assert( quant.amount > 0, "must purchase a positive amount" );
 
       auto fee = quant;
-      fee.amount = ( fee.amount + 199 ) / 200; /// .5% fee
+      fee.amount = ( fee.amount + 199 ) / 200; /// .5% fee (round up)
+      // fee.amount cannot be 0 since that is only possible if quant.amount is 0 which is not allowed by the assert above.
+      // If quant.amount == 1, then fee.amount == 1,
+      // otherwise if quant.amount > 1, then 0 < fee.amount < quant.amount.
       auto quant_after_fee = quant;
       quant_after_fee.amount -= fee.amount;
+      // quant_after_fee.amount should be > 0 if quant.amount > 1.
+      // If quant.amount == 1, then quant_after_fee.amount == 0 and the next inline transfer will fail causing the buyram action to fail.
 
       INLINE_ACTION_SENDER(eosio::token, transfer)( N(eosio.token), {payer,N(active)},
          { payer, N(eosio.ram), quant_after_fee, std::string("buy ram") } );

contracts/eosio.system/eosio.system.abi

@@ -319,10 +319,7 @@
         {"name":"staked",               "type":"int64"},
         {"name":"last_vote_weight",     "type":"float64"},
         {"name":"proxied_vote_weight",  "type":"float64"},
-        {"name":"is_proxy",             "type":"bool"},
-        {"name":"deferred_trx_id",      "type":"uint32"},
-        {"name":"last_unstake_time",    "type":"time_point_sec"},
-        {"name":"unstaking",            "type":"asset"}
+        {"name":"is_proxy",             "type":"bool"}
       ]
     },{
       "name": "claimrewards",

contracts/eosio.system/eosio.system.hpp

@@ -102,14 +102,14 @@ namespace eosiosystem {
       bool                        is_proxy = 0; /// whether the voter is a proxy for others
 
 
-      uint32_t                    deferred_trx_id = 0; /// the ID of the 3-day delay deferred transaction
-      time                        last_unstake_time = 0; /// the time when the deferred_trx_id was sent
-      eosio::asset                unstaking; /// the total unstaking (pending 3 day delay)
+      uint32_t                    reserved1 = 0;
+      time                        reserved2 = 0;
+      eosio::asset                reserved3;
 
       uint64_t primary_key()const { return owner; }
 
       // explicit serialization macro is not necessary, used here only to improve compilation time
-      EOSLIB_SERIALIZE( voter_info, (owner)(proxy)(producers)(staked)(last_vote_weight)(proxied_vote_weight)(is_proxy)(deferred_trx_id)(last_unstake_time)(unstaking) )
+      EOSLIB_SERIALIZE( voter_info, (owner)(proxy)(producers)(staked)(last_vote_weight)(proxied_vote_weight)(is_proxy)(reserved1)(reserved2)(reserved3) )
    };
 
    typedef eosio::multi_index< N(voters), voter_info>  voters_table;

unittests/eosio_system_tester.hpp

@@ -552,9 +552,6 @@ inline fc::mutable_variant_object voter( account_name acct ) {
       //("last_vote_weight", double(0))
       ("proxied_vote_weight", double(0))
       ("is_proxy", 0)
-      ("deferred_trx_id", 0)
-      ("last_unstake_time", fc::time_point_sec() )
-      ("unstaking", asset() )
       ;
 }