refactor run callback

add Server.error
fix bug in run callback (accepts not defined)
fix bug in stream.body event (part is undefined)

lib/express/core.js

@@ -211,17 +211,11 @@ Server = Class({
         request.setBodyEncoding('binary')
         var pendingFiles = 0
         function callback(e, result) {
-          if (!e)
-            if (!pendingFiles) return self.route(request, response)
+          if (!e) {
+            if (!pendingFiles) self.route(request, response)
+          }
           else
-            // TODO: refactore -- same code used in #route(); make util
-            if (request.accepts('html') && set('show exceptions'))
-              request.halt(500, require('express/pages/show-exceptions').render(request, e))
-            else
-              request.halt(500)
-            if (set('throw exceptions'))
-              throw error
-            else self.route(request, response)  
+            self.error(e, request, response)
         }
         if (request.headers['content-type'] &&
             request.headers['content-type'].indexOf('multipart/form-data') !== -1) {
@@ -245,9 +239,9 @@ Server = Class({
             .addListener('partEnd', function(part) {
               if (!part.name) return
               if (part.fileStream)
-                part.fileStream.close(function(){ 
+                part.fileStream.close(function(){
                   --pendingFiles
-                  callback(null)
+                  callback()
                 }),
                 utils.mergeParam(part.name, { filename: part.filename, tempfile: part.tempfile }, request.params.post)                    
               else
@@ -282,15 +276,29 @@ Server = Class({
         request.halt(200, body)
     }
     catch (e) {
-      if (e instanceof ExpressError)
-        throw e
-      if (request.accepts('html') && set('show exceptions'))
-        request.halt(500, require('express/pages/show-exceptions').render(request, e))
-      else
-        request.halt(500)
-      if (set('throw exceptions'))
-        throw e
+      this.error(e, request)
     }
+  },
+
+  /**
+   * Handle errors
+   * @param {object} e
+   * @param  {object} request
+   * @param  {object} response
+   * @api private
+   */
+  error: function (e, request, response) {
+    if (e instanceof ExpressError)
+      throw e
+    if (!(request instanceof Request))
+      request = new Request(request, response),
+      request.trigger('request')
+    if (request.accepts('html') && set('show exceptions'))
+      request.halt(500, require('express/pages/show-exceptions').render(request, e))
+    else
+      request.halt(500)
+    if (set('throw exceptions'))
+      throw e
   }
 })