Wallet extensions: log errors when deserializing a non-mandatory extension and remove it from the wallet if deserialization throws.

core/src/main/java/org/bitcoinj/core/Wallet.java

@@ -18,6 +18,7 @@
 package org.bitcoinj.core;
 
 import com.google.common.annotations.*;
+import com.google.common.base.*;
 import com.google.common.base.Objects;
 import com.google.common.base.Objects.*;
 import com.google.common.collect.*;
@@ -4457,7 +4458,8 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
 
     /**
      * Deserialize the wallet extension with the supplied data and then install it, replacing any existing extension
-     * that may have existed with the same ID.
+     * that may have existed with the same ID. If an exception is thrown then the extension is removed from the wallet,
+     * if already present.
      */
     public void deserializeExtension(WalletExtension extension, byte[] data) throws Exception {
         lock.lock();
@@ -4465,6 +4467,10 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
             // This method exists partly to establish a lock ordering of wallet > extension.
             extension.deserializeWalletExtension(this, data);
             extensions.put(extension.getWalletExtensionID(), extension);
+        } catch (Throwable throwable) {
+            log.error("Error during extension deserialization", throwable);
+            extensions.remove(extension.getWalletExtensionID());
+            Throwables.propagate(throwable);
         } finally {
             lock.unlock();
         }

core/src/main/java/org/bitcoinj/store/WalletProtobufSerializer.java

@@ -519,10 +519,8 @@ public class WalletProtobufSerializer {
                     wallet.deserializeExtension(extension, extProto.getData().toByteArray());
                 } catch (Exception e) {
                     if (extProto.getMandatory() && requireMandatoryExtensions) {
-                        log.error("Error whilst reading extension {}, failing to read wallet", id, e);
+                        log.error("Error whilst reading mandatory extension {}, failing to read wallet", id);
                         throw new UnreadableWalletException("Could not parse mandatory extension in wallet: " + id);
-                    } else {
-                        log.error("Error whilst reading extension {}, ignoring", id, e);
                     }
                 }
             }

core/src/test/java/org/bitcoinj/store/WalletProtobufSerializerTest.java

@@ -332,7 +332,7 @@ public class WalletProtobufSerializerTest {
     }
 
     @Test
-    public void testExtensions() throws Exception {
+    public void extensions() throws Exception {
         myWallet.addExtension(new FooWalletExtension("com.whatever.required", true));
         Protos.Wallet proto = new WalletProtobufSerializer().walletToProto(myWallet);
         // Initial extension is mandatory: try to read it back into a wallet that doesn't know about it.
@@ -355,6 +355,35 @@ public class WalletProtobufSerializerTest {
         assertEquals(0, wallet5.getExtensions().size());
     }
 
+    @Test
+    public void extensionsWithError() throws Exception {
+        WalletExtension extension = new WalletExtension() {
+            @Override
+            public String getWalletExtensionID() {
+                return "test";
+            }
+
+            @Override
+            public boolean isWalletExtensionMandatory() {
+                return false;
+            }
+
+            @Override
+            public byte[] serializeWalletExtension() {
+                return new byte[0];
+            }
+
+            @Override
+            public void deserializeWalletExtension(Wallet containingWallet, byte[] data) throws Exception {
+                throw new NullPointerException();  // Something went wrong!
+            }
+        };
+        myWallet.addExtension(extension);
+        Protos.Wallet proto = new WalletProtobufSerializer().walletToProto(myWallet);
+        Wallet wallet = new WalletProtobufSerializer().readWallet(params, new WalletExtension[]{extension}, proto);
+        assertEquals(0, wallet.getExtensions().size());
+    }
+
     @Test(expected = UnreadableWalletException.FutureVersion.class)
     public void versions() throws Exception {
         Protos.Wallet.Builder proto = Protos.Wallet.newBuilder(new WalletProtobufSerializer().walletToProto(myWallet));