2 files changed, 54 insertions, 21 deletions

diff --git a/src/index.html b/src/index.html
index 2684c9f..096274d 100644
--- a/src/index.html
+++ b/src/index.html
@@ -280,7 +280,10 @@
                                         <a href="https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki#change" target="_blank">External / Internal</a>
                                     </label>
                                     <div class="col-sm-10">
-                                        <input id="change-bip44" type="text" class="change form-control" value="0">
+                                        <div class="input-group">
+                                          <input id="change-bip44" type="text" class="change form-control" value="0">
+                                          <a class="default-bip44-change-value btn btn-primary input-group-addon" role="button">Default</a>
+                                        </div>
                                     </div>
                                 </div>
                                 <div class="form-group">
diff --git a/src/js/index.js b/src/js/index.js
index 9ace962..23eaa47 100644
--- a/src/js/index.js
+++ b/src/js/index.js
@@ -15,6 +15,7 @@
     var showPrivKey = true;
     var showQr = false;
     var litecoinUseLtub = true;
+    var isDefaultBip44ChangeValue = true;
 
     var entropyChangeTimeoutEvent = null;
     var phraseChangeTimeoutEvent = null;
@@ -71,6 +72,7 @@
     DOM.bip44accountXprv = $("#bip44 .account-xprv");
     DOM.bip44accountXpub = $("#bip44 .account-xpub");
     DOM.bip44change = $("#bip44 .change");
+    DOM.defaultBip44ChangeValue = $("#bip44 .default-bip44-change-value");
     DOM.bip49unavailable = $("#bip49 .unavailable");
     DOM.bip49available = $("#bip49 .available");
     DOM.bip49path = $("#bip49-path");
@@ -136,7 +138,9 @@
         DOM.litecoinUseLtub.on("change", litecoinUseLtubChanged);
         DOM.bip32path.on("input", calcForDerivationPath);
         DOM.bip44account.on("input", calcForDerivationPath);
+        DOM.bip44change.on("input", modifiedDefaultBip44ChangeValue);
         DOM.bip44change.on("input", calcForDerivationPath);
+        DOM.defaultBip44ChangeValue.on("click", resetDefaultBip44ChangeValue);
         DOM.bip49account.on("input", calcForDerivationPath);
         DOM.bip49change.on("input", calcForDerivationPath);
         DOM.bip84account.on("input", calcForDerivationPath);
@@ -739,12 +743,14 @@
             var purpose = parseIntNoNaN(DOM.bip44purpose.val(), 44);
             var coin = parseIntNoNaN(DOM.bip44coin.val(), 0);
             var account = parseIntNoNaN(DOM.bip44account.val(), 0);
-            var change = parseIntNoNaN(DOM.bip44change.val(), 0);
-            var path = "m/";
-            path += purpose + "'/";
-            path += coin + "'/";
-            path += account + "'/";
-            path += change;
+            var change = parseIntNoNaN(DOM.bip44change.val(), "");
+            var path = "m";
+            path += "/" + purpose + "'";
+            path += "/" + coin + "'";
+            path += "/" + account + "'";
+            if (change !== "") {
+              path += "/" + change;
+            }
             DOM.bip44path.val(path);
             var derivationPath = DOM.bip44path.val();
             console.log("Using derivation path from BIP44 tab: " + derivationPath);
@@ -1034,20 +1040,7 @@
                     indexText = indexText + "'";
                 }
                 // Ethereum values are different
-                if ((networks[DOM.network.val()].name == "ETH - Ethereum")
-                    || (networks[DOM.network.val()].name == "ETC - Ethereum Classic")
-                    || (networks[DOM.network.val()].name == "EWT - EnergyWeb")
-                    || (networks[DOM.network.val()].name == "PIRL - Pirl")
-                    || (networks[DOM.network.val()].name == "MIX - MIX")
-                    || (networks[DOM.network.val()].name == "MUSIC - Musicoin")
-                    || (networks[DOM.network.val()].name == "POA - Poa")
-                    || (networks[DOM.network.val()].name == "EXP - Expanse")
-                    || (networks[DOM.network.val()].name == "CLO - Callisto")
-                    || (networks[DOM.network.val()].name == "DXN - DEXON")
-                    || (networks[DOM.network.val()].name == "ELLA - Ellaism")
-                    || (networks[DOM.network.val()].name == "ESN - Ethersocial Network")
-                    || (networks[DOM.network.val()].name == "VET - VeChain")
-                ) {
+                if (networkIsEthereum()) {
                     var privKeyBuffer = keyPair.d.toBuffer(32);
                     privkey = privKeyBuffer.toString('hex');
                     var addressBuffer = ethUtil.privateToAddress(privKeyBuffer);
@@ -1711,6 +1704,23 @@
         return DOM.bip32tab.hasClass("active");
     }
 
+    function networkIsEthereum() {
+        var name = networks[DOM.network.val()].name;
+        return (name == "ETH - Ethereum")
+                    || (name == "ETC - Ethereum Classic")
+                    || (name == "EWT - EnergyWeb")
+                    || (name == "PIRL - Pirl")
+                    || (name == "MIX - MIX")
+                    || (name == "MUSIC - Musicoin")
+                    || (name == "POA - Poa")
+                    || (name == "EXP - Expanse")
+                    || (name == "CLO - Callisto")
+                    || (name == "DXN - DEXON")
+                    || (name == "ELLA - Ellaism")
+                    || (name == "ESN - Ethersocial Network")
+                    || (name == "VET - VeChain")
+    }
+
     function networkHasSegwit() {
         var n = network;
         if ("baseNetwork" in network) {
@@ -1740,10 +1750,30 @@
         return DOM.bip141tab.hasClass("active");
     }
 
+    function setBip44ChangeValue() {
+        if (isDefaultBip44ChangeValue) {
+            if (networkIsEthereum()) {
+                DOM.bip44change.val("");
+            } else {
+                DOM.bip44change.val(0);
+            }
+        }
+    }
+
+    function modifiedDefaultBip44ChangeValue() {
+        isDefaultBip44ChangeValue = false;
+    }
+
+    function resetDefaultBip44ChangeValue() {
+        isDefaultBip44ChangeValue = true;
+        setBip44ChangeValue();
+    }
+
     function setHdCoin(coinValue) {
         DOM.bip44coin.val(coinValue);
         DOM.bip49coin.val(coinValue);
         DOM.bip84coin.val(coinValue);
+        setBip44ChangeValue();
     }
 
     function showSegwitAvailable() {