From 03738183c74d0be43846f96562cb89dce929a953 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 19 Sep 2013 06:38:37 +0200
Subject: [PATCH] dns: fix c-ares error reporting regression

The test case from the previous commit exposed a regression in the way
that c-ares errors are reported to JS land.  Said regression was
introduced in commit 756b622 ("src: add multi-context support").

Fixes the following test failure:

    $ out/Release/node test/simple/test-dns-regress-6244
    util.js:675
      var errname = uv.errname(err);
                       ^
    Error: err >= 0
        at Object.exports._errnoException (util.js:675:20)
        at errnoException (dns.js:43:15)
        at Object.onresolve [as oncomplete] (dns.js:145:19)

lib/dns.js erroneously assumed that the error code was a libuv error
code when it's really a c-ares status code.  Libuv handles getaddrinfo()
style lookups (which is by far the most common type of lookup), that's
why this bug wasn't discovered earlier.
---
 lib/dns.js        |  9 ++++++---
 src/cares_wrap.cc | 44 ++++++++++++++++++++++++++++++++++++--------
 2 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/lib/dns.js b/lib/dns.js
index dd274825b2a..3e4b90f6e3f 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -34,9 +34,12 @@ function errnoException(err, syscall) {
   if (err === uv.UV_EAI_MEMORY ||
       err === uv.UV_EAI_NODATA ||
       err === uv.UV_EAI_NONAME) {
-    var ex = new Error(syscall + ' ENOTFOUND');
-    ex.code = 'ENOTFOUND';
-    ex.errno = 'ENOTFOUND';
+    err = 'ENOTFOUND';
+  }
+  if (typeof err === 'string') {  // c-ares error code.
+    var ex = new Error(syscall + ' ' + err);
+    ex.code = err;
+    ex.errno = err;
     ex.syscall = syscall;
     return ex;
   }
diff --git a/src/cares_wrap.cc b/src/cares_wrap.cc
index 00238788ade..fd25a29e99b 100644
--- a/src/cares_wrap.cc
+++ b/src/cares_wrap.cc
@@ -313,14 +313,42 @@ class QueryWrap {
     assert(status != ARES_SUCCESS);
     Context::Scope context_scope(env()->context());
     HandleScope handle_scope(env()->isolate());
-    Local<Value> argv[] = {
-      Integer::New(status, env()->isolate())
-    };
-    MakeCallback(env(),
-                 object(),
-                 env()->oncomplete_string(),
-                 ARRAY_SIZE(argv),
-                 argv);
+    Local<Value> arg;
+    switch (status) {
+#define V(code)                                                               \
+      case ARES_ ## code:                                                     \
+        arg = FIXED_ONE_BYTE_STRING(env()->isolate(), #code);                 \
+        break;
+      V(ENODATA)
+      V(EFORMERR)
+      V(ESERVFAIL)
+      V(ENOTFOUND)
+      V(ENOTIMP)
+      V(EREFUSED)
+      V(EBADQUERY)
+      V(EBADNAME)
+      V(EBADFAMILY)
+      V(EBADRESP)
+      V(ECONNREFUSED)
+      V(ETIMEOUT)
+      V(EOF)
+      V(EFILE)
+      V(ENOMEM)
+      V(EDESTRUCTION)
+      V(EBADSTR)
+      V(EBADFLAGS)
+      V(ENONAME)
+      V(EBADHINTS)
+      V(ENOTINITIALIZED)
+      V(ELOADIPHLPAPI)
+      V(EADDRGETNETWORKPARAMS)
+      V(ECANCELLED)
+#undef V
+      default:
+        arg = FIXED_ONE_BYTE_STRING(env()->isolate(), "UNKNOWN_ARES_ERROR");
+        break;
+    }
+    MakeCallback(env(), object(), env()->oncomplete_string(), 1, &arg);
   }
 
   // Subclasses should implement the appropriate Parse method.