Increase gas estimate by 100000 wei

To prevent minor gas estimation errors, probably usually related to operating on dynamic state.

Fixes #738.

3 files changed, 28 insertions, 1 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6d88cf70d..4f6e82e94 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Current Master
 
+- Increase default max gas to `100000` over the RPC's `estimateGas` response.
+
 ## 2.13.4 2016-10-17
 
 - Add custom transaction fee field to send form.
diff --git a/app/scripts/lib/idStore.js b/app/scripts/lib/idStore.js
index aa77c3360..9846c84f0 100644
--- a/app/scripts/lib/idStore.js
+++ b/app/scripts/lib/idStore.js
@@ -2,6 +2,7 @@ const EventEmitter = require('events').EventEmitter
 const inherits = require('util').inherits
 const async = require('async')
 const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
 const EthQuery = require('eth-query')
 const KeyStore = require('eth-lightwallet').keystore
 const clone = require('clone')
@@ -266,7 +267,7 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
   function estimateGas(cb){
     query.estimateGas(txParams, function(err, result){
       if (err) return cb(err)
-      txData.estimatedGas = result
+      txData.estimatedGas = self.addGasBuffer(result)
       cb()
     })
   }
@@ -281,6 +282,13 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
   }
 }
 
+IdentityStore.prototype.addGasBuffer = function (gasHex) {
+  var gas = new BN(gasHex, 16)
+  var buffer = new BN('100000', 10)
+  var result = gas.add(buffer)
+  return result.toString(16)
+}
+
 // comes from metamask ui
 IdentityStore.prototype.approveTransaction = function (txId, cb) {
   const configManager = this.configManager
diff --git a/test/unit/idStore-test.js b/test/unit/idStore-test.js
index 31da2cd3d..7f6324645 100644
--- a/test/unit/idStore-test.js
+++ b/test/unit/idStore-test.js
@@ -2,6 +2,7 @@ var assert = require('assert')
 var IdentityStore = require('../../app/scripts/lib/idStore')
 var configManagerGen = require('../lib/mock-config-manager')
 const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
 const async = require('async')
 
 describe('IdentityStore', function() {
@@ -138,4 +139,20 @@ describe('IdentityStore', function() {
       })
     })
   })
+
+  describe('#addGasBuffer', function() {
+    const idStore = new IdentityStore({
+      configManager: configManagerGen(),
+      ethStore: {
+        addAccount(acct) { accounts.push(ethUtil.addHexPrefix(acct)) },
+      },
+    })
+
+    const gas = '0x01'
+    const bnGas = new BN(gas, 16)
+    const result = idStore.addGasBuffer(gas)
+    const bnResult = new BN(result, 16)
+
+    assert.ok(bnResult.gt(gas), 'added more gas as buffer.')
+  })
 })