From d5f47f37d3532e0787b13e72ab24cc0aab77c83a Mon Sep 17 00:00:00 2001
From: Oscar Guindzberg <oscar.guindzberg@gmail.com>
Date: Tue, 20 Jan 2015 12:37:58 -0300
Subject: [PATCH] Allow building a MarriedKeyChain with a watchingKey

---
 .../org/bitcoinj/wallet/DeterministicKeyChain.java   | 12 ++++++++++--
 .../java/org/bitcoinj/wallet/MarriedKeyChain.java    | 10 ++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/org/bitcoinj/wallet/DeterministicKeyChain.java b/core/src/main/java/org/bitcoinj/wallet/DeterministicKeyChain.java
index 2ebf6dd4..dc04931f 100644
--- a/core/src/main/java/org/bitcoinj/wallet/DeterministicKeyChain.java
+++ b/core/src/main/java/org/bitcoinj/wallet/DeterministicKeyChain.java
@@ -162,6 +162,7 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
         protected long seedCreationTimeSecs;
         protected byte[] entropy;
         protected DeterministicSeed seed;
+        protected DeterministicKey watchingKey;
 
         protected Builder() {
         }
@@ -214,6 +215,11 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
             return self();
         }
 
+        public T watchingKey(DeterministicKey watchingKey) {
+            this.watchingKey = watchingKey;
+            return self();
+        }
+
         /** The passphrase to use with the generated mnemonic, or null if you would like to use the default empty string. Currently must be the empty string. */
         public T passphrase(String passphrase) {
             // FIXME support non-empty passphrase
@@ -223,7 +229,7 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
 
 
         public DeterministicKeyChain build() {
-            checkState(random != null || entropy != null || seed != null, "Must provide either entropy or random");
+            checkState(random != null || entropy != null || seed != null || watchingKey!= null, "Must provide either entropy or random or seed or watchingKey");
             checkState(passphrase == null || seed == null, "Passphrase must not be specified with seed");
             DeterministicKeyChain chain;
 
@@ -232,8 +238,10 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
                 chain = new DeterministicKeyChain(random, bits, getPassphrase(), seedCreationTimeSecs);
             } else if (entropy != null) {
                 chain = new DeterministicKeyChain(entropy, getPassphrase(), seedCreationTimeSecs);
-            } else {
+            } else if (seed != null) {
                 chain = new DeterministicKeyChain(seed);
+            } else {
+                chain = new DeterministicKeyChain(watchingKey, seedCreationTimeSecs);
             }
 
             return chain;
diff --git a/core/src/main/java/org/bitcoinj/wallet/MarriedKeyChain.java b/core/src/main/java/org/bitcoinj/wallet/MarriedKeyChain.java
index 3450f909..f2ec0e88 100644
--- a/core/src/main/java/org/bitcoinj/wallet/MarriedKeyChain.java
+++ b/core/src/main/java/org/bitcoinj/wallet/MarriedKeyChain.java
@@ -91,7 +91,7 @@ public class MarriedKeyChain extends DeterministicKeyChain {
         }
 
         public MarriedKeyChain build() {
-            checkState(random != null || entropy != null || seed != null, "Must provide either entropy or random");
+            checkState(random != null || entropy != null || seed != null || watchingKey!= null, "Must provide either entropy or random or seed or watchingKey");
             checkNotNull(followingKeys, "followingKeys must be provided");
             MarriedKeyChain chain;
             if (threshold == 0)
@@ -100,8 +100,10 @@ public class MarriedKeyChain extends DeterministicKeyChain {
                 chain = new MarriedKeyChain(random, bits, getPassphrase(), seedCreationTimeSecs);
             } else if (entropy != null) {
                 chain = new MarriedKeyChain(entropy, getPassphrase(), seedCreationTimeSecs);
-            } else {
+            } else if (seed != null) {
                 chain = new MarriedKeyChain(seed);
+            } else {
+                chain = new MarriedKeyChain(watchingKey, seedCreationTimeSecs);
             }
             chain.addFollowingAccountKeys(followingKeys, threshold);
             return chain;
@@ -117,6 +119,10 @@ public class MarriedKeyChain extends DeterministicKeyChain {
         super(accountKey, false);
     }
 
+    MarriedKeyChain(DeterministicKey accountKey, long seedCreationTimeSecs) {
+        super(accountKey, seedCreationTimeSecs);
+    }
+
     MarriedKeyChain(DeterministicSeed seed, KeyCrypter crypter) {
         super(seed, crypter);
     }