From f470157c8d8304d3d730104f1b4a72e40d45baba Mon Sep 17 00:00:00 2001
From: Ascari <ascari.gtz@gmail.com>
Date: Mon, 24 Jun 2019 11:51:04 -0500
Subject: [PATCH] Bugfix

When using the **conditionalHandler** plugin, if a single version route has a `contentType`, but the other routes do not, it will crash as it tries to call `.join` on a undefined `contentType` field.

See for yourself:

``` bug.js
const restify = require('restify');

const server = restify.createServer();

server.get('/', restify.plugins.conditionalHandler([
  {
    contentType: ['application/json'],
    version: '1.5.0',
    handler: (req, res, next) => {
      res.json({
        version: 0
      })
    }
  },
  {
    // contentType is missing here
    version: '1.1.0',
    handler: (req, res, next) => {
      res.json({
        version: 1
      })
    }
  }
]));
```
---
 lib/plugins/conditionalHandler.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/plugins/conditionalHandler.js b/lib/plugins/conditionalHandler.js
index 7ddf55c1b..f2108c442 100644
--- a/lib/plugins/conditionalHandler.js
+++ b/lib/plugins/conditionalHandler.js
@@ -126,7 +126,7 @@ function conditionalHandler(candidates) {
             reqCandidates = candidates.filter(function filter(candidate) {
                 var neg = new Negotiator({
                     headers: {
-                        accept: candidate.contentType.join(', ')
+                        accept: (candidate.contentType) ? candidate.contentType.join(', ') : ''
                     }
                 });
                 var tmp = neg.preferredMediaType(contentTypes);