From c1bed5fe94db9abeb3dd7418fb7e2feb4d088f97 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Wed, 3 Apr 2019 17:07:15 -0700
Subject: [PATCH 1/2] dns: refactor internal/dns/promises.js

Use `isIP()` instead of `isIPv4()` since it does the additional
functionality that we were adding after our calls to `isIP()`.

This not-so-incidentally also increases code coverage from tests. At
least one of the replaced ternaries was difficult to cover reliably
because operating system/configuration variances were too unpredictable.
---
 lib/internal/dns/promises.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/internal/dns/promises.js b/lib/internal/dns/promises.js
index 25696bf2228b64..c64adb65e541ce 100644
--- a/lib/internal/dns/promises.js
+++ b/lib/internal/dns/promises.js
@@ -7,7 +7,7 @@ const {
 } = require('internal/dns/utils');
 const { codes, dnsException } = require('internal/errors');
 const { toASCII } = require('internal/idna');
-const { isIP, isIPv4, isLegalPort } = require('internal/net');
+const { isIP, isLegalPort } = require('internal/net');
 const {
   getaddrinfo,
   getnameinfo,
@@ -31,7 +31,7 @@ function onlookup(err, addresses) {
     return;
   }
 
-  const family = this.family ? this.family : isIPv4(addresses[0]) ? 4 : 6;
+  const family = this.family ? this.family : isIP(addresses[0]);
   this.resolve({ address: addresses[0], family });
 }
 
@@ -48,7 +48,7 @@ function onlookupall(err, addresses) {
 
     addresses[i] = {
       address,
-      family: family ? family : isIPv4(addresses[i]) ? 4 : 6
+      family: family ? family : isIP(addresses[i])
     };
   }
 

From d3c742101608e726699e5392966e54a4783e5767 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Tue, 16 Apr 2019 11:07:17 -0700
Subject: [PATCH 2/2] dns: do not indicate invalid IPs are IPv6

In lib/dns.js, use `isIP()` instead of `isIPv4()` for determining the
`family` property in `lookup()`. If an invalid IP address is returned,
the `family` currently provided is `6`. With this change, it will be
`0`. Update documentation to reflect this.
---
 doc/api/dns.md | 4 +++-
 lib/dns.js     | 6 +++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/doc/api/dns.md b/doc/api/dns.md
index 1dc4f50ef668d2..8e4dd9bc81e8c8 100644
--- a/doc/api/dns.md
+++ b/doc/api/dns.md
@@ -154,7 +154,9 @@ changes:
 * `callback` {Function}
   - `err` {Error}
   - `address` {string} A string representation of an IPv4 or IPv6 address.
-  - `family` {integer} `4` or `6`, denoting the family of `address`.
+  - `family` {integer} `4` or `6`, denoting the family of `address`, or `0` if
+    the address is not an IPv4 or IPv6 address. `0` is a likely indicator of a
+    bug in the name resolution service used by the operating system.
 
 Resolves a hostname (e.g. `'nodejs.org'`) into the first found A (IPv4) or
 AAAA (IPv6) record. All `option` properties are optional. If `options` is an
diff --git a/lib/dns.js b/lib/dns.js
index 3d057d6b50081d..fba27ea77e2c37 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -23,7 +23,7 @@
 
 const cares = internalBinding('cares_wrap');
 const { toASCII } = require('internal/idna');
-const { isIP, isIPv4, isLegalPort } = require('internal/net');
+const { isIP, isLegalPort } = require('internal/net');
 const { customPromisifyArgs } = require('internal/util');
 const errors = require('internal/errors');
 const {
@@ -60,7 +60,7 @@ function onlookup(err, addresses) {
   if (this.family) {
     this.callback(null, addresses[0], this.family);
   } else {
-    this.callback(null, addresses[0], isIPv4(addresses[0]) ? 4 : 6);
+    this.callback(null, addresses[0], isIP(addresses[0]));
   }
 }
 
@@ -75,7 +75,7 @@ function onlookupall(err, addresses) {
     const addr = addresses[i];
     addresses[i] = {
       address: addr,
-      family: family || (isIPv4(addr) ? 4 : 6)
+      family: family || isIP(addr)
     };
   }