Change default tombstone blocks to 10.

API.md

@@ -1320,7 +1320,7 @@ curl -s localhost:9090/wallet \
 | :------------- | :----------------------- | :------------------------ |
 | `input_txo_ids` | Specific TXOs to use as inputs to this transaction   | TXO IDs (obtain from `get_all_txos_for_account`) |
 | `fee` | The fee amount to submit with this transaction | If not provided, uses `MINIMUM_FEE` = .01 MOB |
-| `tombstone_block` | The block after which this transaction expires | If not provided, uses `cur_height` + 100 |
+| `tombstone_block` | The block after which this transaction expires | If not provided, uses `cur_height` + 10 |
 | `max_spendable_value` | The maximum amount for an input TXO selected for this transaction |  |
 
 Note, as the tx_proposal json object is quite large, you may wish to write the result to a file for use in the submit_transaction call, such as:

full-service/src/json_rpc/e2e.rs

@@ -722,7 +722,7 @@ mod e2e {
 
         // Tombstone block = last ledger block at 11 + 2 new blocks + 100
         let prefix_tombstone = tx_prefix.get("tombstone_block").unwrap();
-        assert_eq!(prefix_tombstone, "113");
+        assert_eq!(prefix_tombstone, "23");
 
         // Get current balance
         assert_eq!(ledger_db.num_blocks().unwrap(), 14);

full-service/src/service/receipt.rs

@@ -469,7 +469,7 @@ mod tests {
         let txo_pubkey =
             mc_util_serial::decode(&txos[0].txo.public_key).expect("Could not decode pubkey");
         assert_eq!(receipt.public_key, txo_pubkey);
-        assert_eq!(receipt.tombstone_block, 112); // Ledger seeded up to block 11 at tx construction, then one appended + 100
+        assert_eq!(receipt.tombstone_block, 22); // Ledger seeded up to block 11 at tx construction, then one appended + 10
         let txo: TxOut = mc_util_serial::decode(&txos[0].txo.txo).expect("Could not decode txo");
         assert_eq!(receipt.amount, txo.amount);
         assert_eq!(receipt.confirmation, confirmations[0].confirmation);

full-service/src/service/transaction_builder.rs

@@ -30,7 +30,7 @@ use mc_mobilecoind::{
     UnspentTxOut,
 };
 use mc_transaction_core::{
-    constants::{MAX_TOMBSTONE_BLOCKS, MINIMUM_FEE, RING_SIZE},
+    constants::{MINIMUM_FEE, RING_SIZE},
     onetime_keys::recover_onetime_private_key,
     ring_signature::KeyImage,
     tx::{TxOut, TxOutMembershipProof},
@@ -42,6 +42,10 @@ use diesel::prelude::*;
 use rand::Rng;
 use std::{convert::TryFrom, iter::FromIterator, str::FromStr, sync::Arc};
 
+/// Default number of blocks in the future to set the transaction tombstone
+/// block.
+const DEFAULT_TOMBSTONE_BLOCKS: u64 = 10;
+
 /// A builder of transactions constructed from this wallet.
 pub struct WalletTransactionBuilder<FPR: FogPubkeyResolver + 'static> {
     /// Account ID (hex-encoded) from which to construct a transaction.
@@ -174,7 +178,7 @@ impl<FPR: FogPubkeyResolver + 'static> WalletTransactionBuilder<FPR> {
             tombstone
         } else {
             let last_block_index = self.ledger_db.num_blocks()? - 1;
-            last_block_index + MAX_TOMBSTONE_BLOCKS
+            last_block_index + DEFAULT_TOMBSTONE_BLOCKS
         };
         self.tombstone = tombstone_block;
         Ok(())
@@ -821,7 +825,7 @@ mod tests {
         // Not setting the tombstone results in tombstone = 0. This is an acceptable
         // value,
         let proposal = builder.build().unwrap();
-        assert_eq!(proposal.tx.prefix.tombstone_block, 112);
+        assert_eq!(proposal.tx.prefix.tombstone_block, 22);
 
         // Build a transaction and explicitly set tombstone
         let (recipient, mut builder) =