From 4fee7b41288df4be6f532181a0814e373260543b Mon Sep 17 00:00:00 2001
From: Fedor Indutny <fedor@indutny.com>
Date: Thu, 8 Jun 2017 16:49:17 -0400
Subject: [PATCH] lib: fix `resolve4` usage on node < v6.11.0

---
 .travis.yml       |  6 ++++++
 lib/redns.js      | 17 +++++++++++++++--
 package-lock.json |  5 +++++
 package.json      |  1 +
 4 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 .travis.yml

diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..135fa30
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,6 @@
+sudo: false
+language: node_js
+node_js:
+  - "4"
+  - "6"
+  - "latest"
diff --git a/lib/redns.js b/lib/redns.js
index f24b227..b33d5e5 100644
--- a/lib/redns.js
+++ b/lib/redns.js
@@ -4,6 +4,9 @@ const dns = require('dns');
 const async = require('async');
 const debug = require('debug')('redns');
 
+// See: https://github.com/nodejs/node/pull/9296
+const isLegacy = require('compare-versions')(process.version, 'v6.11.0') < 0;
+
 // For later monkey-patching in user code
 const dnsLookup = dns.lookup;
 
@@ -169,7 +172,7 @@ ReDNS.prototype._resolve = function _resolve(hostname, family, callback) {
       callback(new Error('DNS query timed out'));
     }, timeout);
 
-    resolver(hostname, options, (err, results) => {
+    const onResults = (err, results) => {
       // Timed out
       if (done)
         return;
@@ -183,9 +186,19 @@ ReDNS.prototype._resolve = function _resolve(hostname, family, callback) {
         if (typeof result === 'string')
           return { address: result, ttl: Infinity, family };
 
+        // Node.js before v6.11.0 has no way to get record's TTL
+        // fallback to `maxTTL` option
+        if (isLegacy)
+          return { address: result.address, ttl: Infinity, family };
+
         return { address: result.address, ttl: result.ttl, family };
       }));
-    });
+    };
+
+    if (isLegacy)
+      resolver(hostname, onResults);
+    else
+      resolver(hostname, options, onResults);
   }, callback);
 };
 
diff --git a/package-lock.json b/package-lock.json
index dfa3f23..1a6f783 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -168,6 +168,11 @@
       "integrity": "sha1-nJkJQXbhIkDLItbFFGCYQA/g99Q=",
       "dev": true
     },
+    "compare-versions": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/compare-versions/-/compare-versions-3.0.1.tgz",
+      "integrity": "sha1-5gkVt/spTim7tghpGIdivuuHFEM="
+    },
     "concat-map": {
       "version": "0.0.1",
       "resolved": "https://registry.npmjs.org/concat-map/-/concat-map-0.0.1.tgz",
diff --git a/package.json b/package.json
index 287a158..254be67 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
   },
   "dependencies": {
     "async": "^2.4.1",
+    "compare-versions": "^3.0.1",
     "debug": "^2.6.8"
   }
 }