From e7e56ada0732451c6f4482745103f1b85dbf0d2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ask=20Bj=C3=B8rn=20Hansen?= <ask@develooper.com>
Date: Fri, 10 May 2013 16:21:13 -0700
Subject: [PATCH 1/2] Don't try to close the client config file if opening
 fails

$ q
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x9c124]

goroutine 1 [running]:
os.(*File).Close(0x0, 0xf800000010, 0x0, 0xf840054e40)
/usr/local/go/src/pkg/os/file_unix.go:99 +0x1c
github.com/miekg/dns.ClientConfigFromFile(0x1c3294, 0x6374652f00000010, 0x0, 0xf840054e40, 0xf840054de0, ...)
/Users/ask/go/src/github.com/miekg/dns/clientconfig.go:30 +0xcc
main.main()
/Users/ask/go/src/github.com/miekg/dns/ex/q/q.go:50 +0x45b
---
 clientconfig.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clientconfig.go b/clientconfig.go
index f6284fed..ed77e4f0 100644
--- a/clientconfig.go
+++ b/clientconfig.go
@@ -25,10 +25,10 @@ type ClientConfig struct {
 // a *ClientConfig.
 func ClientConfigFromFile(conf string) (*ClientConfig, error) {
 	file, err := os.Open(conf)
-	defer file.Close()
 	if err != nil {
 		return nil, err
 	}
+	defer file.Close()
 	c := new(ClientConfig)
 	b := bufio.NewReader(file)
 	c.Servers = make([]string, 0)

From e4a33cd4945f1d675cb9ea8b80a284514788f3aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ask=20Bj=C3=B8rn=20Hansen?= <ask@develooper.com>
Date: Fri, 10 May 2013 22:51:23 -0700
Subject: [PATCH 2/2] Work without resolv.conf if the nameserver is specified
 with @...

---
 ex/q/q.go | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/ex/q/q.go b/ex/q/q.go
index fcc1cf80..ba12a5e7 100644
--- a/ex/q/q.go
+++ b/ex/q/q.go
@@ -47,8 +47,6 @@ func main() {
 		flag.PrintDefaults()
 	}
 
-	conf, _ := dns.ClientConfigFromFile("/etc/resolv.conf")
-	nameserver := "@" + conf.Servers[0]
 	qtype := uint16(0)
 	qclass := uint16(dns.ClassINET)
 	var qname []string
@@ -70,6 +68,8 @@ func main() {
 		}
 	}
 
+	var nameserver string
+
 Flags:
 	for i := 0; i < flag.NArg(); i++ {
 		// If it starts with @ it is a nameserver
@@ -109,6 +109,15 @@ Flags:
 		qtype = dns.TypeA
 	}
 
+	if len(nameserver) == 0 {
+		conf, err := dns.ClientConfigFromFile("/etc/resolv.conf")
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(2)
+		}
+		nameserver = "@" + conf.Servers[0]
+	}
+
 	nameserver = string([]byte(nameserver)[1:]) // chop off @
 	// if the nameserver is from /etc/resolv.conf the [ and ] are already
 	// added, thereby breaking net.ParseIP. Check for this and don't