fix callback called twice for client/request

This fixes the errback being called twice when both a client and
request error occur on the same command call.

Changelog.md

@@ -1,5 +1,9 @@
 # node-bitcoin changelog
 
+## v1.2.2 (2012/04/26)
+Fix callback being called twice when a client and request error
+occur on the same command call.
+
 ## v1.2.1 (2012/04/26)
 * Add missing `getBlock` command
 

lib/jsonrpc.js

@@ -15,6 +15,7 @@ var Client = function(port, host, user, password) {
 
   this.call = function(method, params, callback, errback, path) {
     var client = http.createClient(port, host);
+    var clientRequestErrorCalled = false;
 
     // First we encode the request into JSON
     var requestJSON = JSON.stringify({
@@ -40,14 +41,15 @@ var Client = function(port, host, user, password) {
 
     var request = client.request('POST', path || '/', headers);
     request.write(requestJSON);
-
-    client.on('error', function(e){
-      errback(e);
-    });
-
-    request.on('error', function(e){
-      errback(e);
-    });
+    
+    function clientRequestErrorHandler(e) {
+      if (!clientRequestErrorCalled) {
+        clientRequestErrorCalled = true;
+        errback(e);
+      }
+    }
+    client.on('error', clientRequestErrorHandler);
+    request.on('error', clientRequestErrorHandler);
 
     request.on('response', function(response) {
       // We need to buffer the response chunks in a nonblocking way.

test/api.js

@@ -174,5 +174,21 @@ vows.describe('api').addBatch({
       },
     },
   },
+  'creating a client on a non-listening port': {
+    topic: function() {
+      return new bitcoin.Client(config.host, 9897, 'baduser', 'badpwd');
+    },
+    'will return client object': function(client) {
+      assert.equal(typeof client, 'object');
+    },
+    'but when calling a command': {
+      topic: function(client) {
+        client.listSinceBlock(this.callback);
+      },
+      'should not call callback more than once': function(err, result) {
+        assert.instanceOf(err, Error);
+      }
+    }
+  }
   
 }).export(module);