From 9fe483ca767b64de3e9b9e2c78b7bfaf420861c2 Mon Sep 17 00:00:00 2001
From: mako-taco <jake.y.scott@gmail.com>
Date: Sun, 22 Dec 2013 12:26:21 -0500
Subject: [PATCH 1/4] handle manually written responses

---
 lib/application.js  |  2 ++
 test/application.js | 55 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/lib/application.js b/lib/application.js
index be1a6b2..babf4c6 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -184,6 +184,8 @@ function *respond(next){
   yield next;
 
   var res = this.res;
+  if (res.headersSent || !res.socket.writable) return;
+
   var body = this.body;
   var head = 'HEAD' == this.method;
   var noContent = ~[204, 205, 304].indexOf(this.status);
diff --git a/test/application.js b/test/application.js
index 29c433b..073e484 100644
--- a/test/application.js
+++ b/test/application.js
@@ -134,6 +134,61 @@ describe('app.respond', function(){
     })
   })
 
+  describe('when res has already been written to', function(){
+
+    it('should not cause an app error', function(done){
+      var app = koa();
+
+      app.use(function *(next){
+        var res = this.res;
+        res.setHeader("Content-Type", "text/html")
+        res.status = 200;
+        res.write('Hello');
+        setTimeout(function () {
+          res.end("Goodbye")
+        }, 0);
+      });
+
+      var errorCaught = false;
+
+      app.on('error', function (err) {
+        errorCaught = err;
+      });
+
+      var server = app.listen();
+
+      request(server)
+      .get('/')
+      .expect(200)
+      .end(function(err, res){
+        if (err) return done(err);
+        if (errorCaught) return done(errorCaught);
+        done();
+      });
+    })
+
+    it('should send the right body', function(done){
+      var app = koa();
+
+      app.use(function *(next){
+        var res = this.res;
+        res.setHeader("Content-Type", "text/html")
+        res.status = 200;
+        res.write('Hello');
+        setTimeout(function () {
+          res.end("Goodbye")
+        }, 0);
+      });
+
+      var server = app.listen();
+
+      request(server)
+      .get('/')
+      .expect(200)
+      .expect('HelloGoodbye', done);
+    })
+  })
+
   describe('when .body is missing', function(){
     describe('with status=400', function(){
       it('should respond with the associated status message', function(done){

From 0d9336622c6e9d01abec01bc4a17ab9736d46252 Mon Sep 17 00:00:00 2001
From: Jonathan Ong <jonathanrichardong@gmail.com>
Date: Sun, 22 Dec 2013 14:48:28 -0800
Subject: [PATCH 2/4] use yield *next internally

---
 lib/application.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/application.js b/lib/application.js
index babf4c6..89e575c 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -181,7 +181,7 @@ function *respond(next){
   this.status = 200;
   if (this.app.poweredBy) this.set('X-Powered-By', 'koa');
 
-  yield next;
+  yield *next;
 
   var res = this.res;
   if (res.headersSent || !res.socket.writable) return;

From b56531f75d558c3670ed6881031eca31f99acb41 Mon Sep 17 00:00:00 2001
From: Jonathan Ong <jonathanrichardong@gmail.com>
Date: Sun, 22 Dec 2013 15:13:01 -0800
Subject: [PATCH 3/4] bump koa compose to 2.1.0

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 24aaba7..c87ca5e 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,7 @@
     "mime": "~1.2.11",
     "fresh": "~0.2.0",
     "negotiator": "~0.3.0",
-    "koa-compose": "~2.0.1",
+    "koa-compose": "~2.1.0",
     "cookies": "~0.3.7",
     "keygrip": "~1.0.0"
   },

From b047805f9e93103733d1b88726339cf98e40c71c Mon Sep 17 00:00:00 2001
From: yosssi <yoshida.keiji.84@gmail.com>
Date: Tue, 24 Dec 2013 21:13:42 +0900
Subject: [PATCH 4/4] Fixed the link url to the list of middlewares on
 docs/api/index.md.

---
 docs/api/index.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/api/index.md b/docs/api/index.md
index a0e787b..fa77426 100644
--- a/docs/api/index.md
+++ b/docs/api/index.md
@@ -126,7 +126,7 @@ http.createServer(app.callback()).listen(3001);
 
 ## app.use(function)
 
-  Add the given middleware function to this application. See [Middleware](#middleware) for
+  Add the given middleware function to this application. See [Middleware](https://github.com/koajs/koa/wiki#middleware) for
   more information.
 
 ## app.keys=