wallet_rpc_server: add weight to describe_transfer

diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index e64df58..4f8f801 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -1472,6 +1472,7 @@ namespace tools
     }
 
     std::vector <wallet2::tx_construction_data> tx_constructions;
+    std::vector<uint64_t> tx_weights;
     if (!req.unsigned_txset.empty()) {
       try {
         tools::wallet2::unsigned_tx_set exported_txs;
@@ -1487,6 +1488,8 @@ namespace tools
           return false;
         }
         tx_constructions = exported_txs.txes;
+        // An unsigned txset does not contain a transaction with an exact weight yet.
+        tx_weights.resize(tx_constructions.size());
       }
       catch (const std::exception &e) {
         er.code = WALLET_RPC_ERROR_CODE_BAD_UNSIGNED_TX_DATA;
@@ -1510,6 +1513,7 @@ namespace tools
 
         for (size_t n = 0; n < exported_txs.m_ptx.size(); ++n) {
           tx_constructions.push_back(exported_txs.m_ptx[n].construction_data);
+          tx_weights.push_back(cryptonote::get_transaction_weight(exported_txs.m_ptx[n].tx));
         }
       }
       catch (const std::exception &e) {
@@ -1532,8 +1536,9 @@ namespace tools
       for (size_t n = 0; n < tx_constructions.size(); ++n)
       {
         const tools::wallet2::tx_construction_data &cd = tx_constructions[n];
-        res.desc.push_back({0, 0, std::numeric_limits<uint32_t>::max(), 0, {}, {}, "", 0, "", 0, 0, ""});
+        res.desc.push_back({0, 0, std::numeric_limits<uint32_t>::max(), 0, {}, {}, "", 0, "", 0, 0, 0, ""});
         wallet_rpc::COMMAND_RPC_DESCRIBE_TRANSFER::transfer_description &desc = res.desc.back();
+        desc.weight = tx_weights[n];
         // Clear the recipients collection ready for this loop iteration
         tx_dests.clear();
 
diff --git a/src/wallet/wallet_rpc_server_commands_defs.h b/src/wallet/wallet_rpc_server_commands_defs.h
index 09d4ae9..65ed149 100644
--- a/src/wallet/wallet_rpc_server_commands_defs.h
+++ b/src/wallet/wallet_rpc_server_commands_defs.h
@@ -47,7 +47,7 @@
 // advance which version they will stop working with
 // Don't go over 32767 for any of these
 #define WALLET_RPC_VERSION_MAJOR 1
-#define WALLET_RPC_VERSION_MINOR 31
+#define WALLET_RPC_VERSION_MINOR 32
 #define MAKE_WALLET_RPC_VERSION(major,minor) (((major)<<16)|(minor))
 #define WALLET_RPC_VERSION MAKE_WALLET_RPC_VERSION(WALLET_RPC_VERSION_MAJOR, WALLET_RPC_VERSION_MINOR)
 namespace tools
@@ -736,6 +736,7 @@ namespace wallet_rpc
       uint64_t change_amount;
       std::string change_address;
       uint64_t fee;
+      uint64_t weight;
       uint32_t dummy_outputs;
       std::string extra;
 
@@ -750,6 +751,7 @@ namespace wallet_rpc
         KV_SERIALIZE(change_amount)
         KV_SERIALIZE(change_address)
         KV_SERIALIZE(fee)
+        KV_SERIALIZE_OPT(weight, (uint64_t)0)
         KV_SERIALIZE(dummy_outputs)
         KV_SERIALIZE(extra)
       END_KV_SERIALIZE_MAP()
diff --git a/tests/functional_tests/cold_signing.py b/tests/functional_tests/cold_signing.py
index 7220a91..542cb96 100755
--- a/tests/functional_tests/cold_signing.py
+++ b/tests/functional_tests/cold_signing.py
@@ -190,6 +190,7 @@ class ColdSigningTest():
         assert desc.change_amount == desc.amount_in - 1000000000000 - fee
         assert desc.change_address == STANDARD_ADDRESS
         assert desc.fee == fee
+        assert 'weight' not in desc
         assert len(desc.recipients) == 1
         rec = desc.recipients[0]
         assert rec.address == destination_addr
diff --git a/tests/functional_tests/multisig.py b/tests/functional_tests/multisig.py
index a2dbfda..17c94c8 100755
--- a/tests/functional_tests/multisig.py
+++ b/tests/functional_tests/multisig.py
@@ -374,6 +374,7 @@ class MultisigTest():
         amount = res.amount
         assert res.fee > 0
         fee = res.fee
+        weight = res.weight
         assert len(res.tx_blob) == 0
         assert len(res.tx_metadata) == 0
         assert len(res.multisig_txset) > 0
@@ -397,6 +398,7 @@ class MultisigTest():
           assert desc.change_amount == desc.amount_in - 1000000000000 - fee
           assert desc.change_address == self.wallet_address
           assert desc.fee == fee
+          assert desc.weight == weight
           assert len(desc.recipients) == 1
           rec = desc.recipients[0]
           assert rec.address == '42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm'
@@ -413,6 +415,10 @@ class MultisigTest():
             except: ok = True
             assert ok
 
+        res = self.wallet[signers[-1]].describe_transfer(multisig_txset = multisig_txset)
+        assert len(res.desc) == 1
+        assert res.desc[0].weight == weight
+
         print('Submitting multisig transaction with wallet ' + str(signers[-1]))
         res = self.wallet[signers[-1]].submit_multisig(multisig_txset)
         assert len(res.tx_hash_list) == 1
@@ -470,6 +476,7 @@ class MultisigTest():
         amount = res.amount
         assert res.fee > 0
         fee = res.fee
+        weight = res.weight
         assert len(res.tx_blob) == 0
         assert len(res.tx_metadata) == 0
         assert len(res.multisig_txset) > 0
@@ -522,6 +529,7 @@ class MultisigTest():
           assert desc.change_amount == desc.amount_in - 1000000000000 - fee
           assert desc.change_address == self.wallet_address
           assert desc.fee == fee
+          assert desc.weight == weight
           assert len(desc.recipients) == 1
           rec = desc.recipients[0]
           assert rec.address == '42ey1afDFnn4886T7196doS9GPMzexD9gXpsZJDwVjeRVdFCSoHnv7KPbBeGpzJBzHRCAs9UxqeoyFQMYbqSWYTfJJQAWDm'