Reproduced issue 743 in test case

This contract hex does include the value `f4`, but it was compiled from a contract with no instance of `.delegatecall`. I believe `f4` in this case is part of some other value or contract address, and `ethBinToOps` has some error in how it skips pushed data.

@kumavis

app/scripts/lib/idStore.js

@@ -249,15 +249,9 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
     if (txParams.to) {
       query.getCode(txParams.to, function (err, result) {
         if (err) return cb(err)
-        var code = ethUtil.toBuffer(result)
+        var containsDelegateCall = this.checkForDelegateCall(result)
-        if (code !== '0x') {
+        txData.containsDelegateCall = containsDelegateCall
-          var ops = ethBinToOps(code)
+        cb()
-          var containsDelegateCall = ops.some((op) => op.name === 'DELEGATECALL')
-          txData.containsDelegateCall = containsDelegateCall
-          cb()
-        } else {
-          cb()
-        }
       })
     } else {
       cb()
@@ -282,6 +276,17 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
   }
 }
 
+IdentityStore.prototype.checkForDelegateCall = function (codeHex) {
+  const code = ethUtil.toBuffer(codeHex)
+  if (code !== '0x') {
+    const ops = ethBinToOps(code)
+    const containsDelegateCall = ops.some((op) => op.name === 'DELEGATECALL')
+    return containsDelegateCall
+  } else {
+    return false
+  }
+}
+
 IdentityStore.prototype.addGasBuffer = function (gasHex) {
   var gas = new BN(gasHex, 16)
   var buffer = new BN('100000', 10)

test/lib/non-delegate-code.txt

@@ -0,0 +1 @@
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

test/unit/idStore-test.js

@@ -1,10 +1,15 @@
-var assert = require('assert')
+const assert = require('assert')
-var IdentityStore = require('../../app/scripts/lib/idStore')
+const IdentityStore = require('../../app/scripts/lib/idStore')
-var configManagerGen = require('../lib/mock-config-manager')
+const configManagerGen = require('../lib/mock-config-manager')
+const fs = require('fs')
+const path = require('path')
 const ethUtil = require('ethereumjs-util')
 const BN = ethUtil.BN
 const async = require('async')
 
+const nonDelegatePath = path.join(__dirname, '..', 'lib', 'non-delegate-code.txt')
+const nonDelegateCode = fs.readFileSync(nonDelegatePath).toString()
+
 describe('IdentityStore', function() {
 
   describe('#createNewVault', function () {
@@ -156,4 +161,16 @@ describe('IdentityStore', function() {
     assert.ok(bnResult.gt(gas), 'added more gas as buffer.')
     assert.equal(result.indexOf('0x'), 0, 'include hex prefix')
   })
+
+  describe('#checkForDelegateCall', function() {
+    const idStore = new IdentityStore({
+      configManager: configManagerGen(),
+      ethStore: {
+        addAccount(acct) { accounts.push(ethUtil.addHexPrefix(acct)) },
+      },
+    })
+
+    var result = idStore.checkForDelegateCall(nonDelegateCode)
+    assert.equal(result, false, 'no delegate call in provided code')
+  })
 })