From 261fa3620fcaf0072e88b775f97b3fa9a980f201 Mon Sep 17 00:00:00 2001
From: Evan Lucas <evanlucas@me.com>
Date: Fri, 27 Feb 2015 16:47:29 -0600
Subject: [PATCH] src: fix intermittent SIGSEGV in resolveTxt

Fixes a SIGSEGV by making sure `txt_chunk` is not empty before setting
it on `txt_records`

Fixes: https://github.com/joyent/node/issues/9285
PR-URL: https://github.com/joyent/node/pull/9300
Reviewed-By: cjihrig - Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: jasnell - James M Snell <jasnell@gmail.com>
---
 src/cares_wrap.cc                     | 5 +++--
 test/internet/test-dns-txt-sigsegv.js | 8 ++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)
 create mode 100644 test/internet/test-dns-txt-sigsegv.js

diff --git a/src/cares_wrap.cc b/src/cares_wrap.cc
index 1764374c12..a6d0dcd8a9 100644
--- a/src/cares_wrap.cc
+++ b/src/cares_wrap.cc
@@ -633,8 +633,9 @@ class QueryTxtWrap: public QueryWrap {
       }
       txt_chunk->Set(j++, txt);
     }
-    // Push last chunk
-    txt_records->Set(i, txt_chunk);
+    // Push last chunk if it isn't empty
+    if (!txt_chunk.IsEmpty())
+      txt_records->Set(i, txt_chunk);
 
     ares_free_data(txt_out);
 
diff --git a/test/internet/test-dns-txt-sigsegv.js b/test/internet/test-dns-txt-sigsegv.js
new file mode 100644
index 0000000000..75d34c21c0
--- /dev/null
+++ b/test/internet/test-dns-txt-sigsegv.js
@@ -0,0 +1,8 @@
+var common = require('../common');
+var assert = require('assert');
+var dns = require('dns');
+
+dns.resolveTxt('www.microsoft.com', function(err, records) {
+  assert.equal(err, null);
+  assert.equal(records.length, 0);
+});