From 5f84d309721a40e0572a773af47c3f7aee6ccaf2 Mon Sep 17 00:00:00 2001
From: Christian Schwarz <me@cschwarz.com>
Date: Sat, 20 May 2017 19:39:32 +0200
Subject: [PATCH] util/ReadWriteCloserLogger: handle unset readlog | writelog

---
 util/io.go | 42 ++++++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 10 deletions(-)

diff --git a/util/io.go b/util/io.go
index 5010115..68ae286 100644
--- a/util/io.go
+++ b/util/io.go
@@ -16,32 +16,54 @@ func NewReadWriteCloserLogger(rwc io.ReadWriteCloser, readlog, writelog string)
 		RWC: rwc,
 	}
 	flags := os.O_CREATE | os.O_WRONLY
-	if l.ReadFile, err = os.OpenFile(readlog, flags, 0600); err != nil {
-		return
+	if readlog != "" {
+		if l.ReadFile, err = os.OpenFile(readlog, flags, 0600); err != nil {
+			return
+		}
 	}
-	if l.WriteFile, err = os.OpenFile(writelog, flags, 0600); err != nil {
-		return
+	if writelog != "" {
+		if l.WriteFile, err = os.OpenFile(writelog, flags, 0600); err != nil {
+			return
+		}
 	}
 	return
 }
 
 func (c *ReadWriteCloserLogger) Read(buf []byte) (n int, err error) {
 	n, err = c.RWC.Read(buf)
-	if _, writeErr := c.ReadFile.Write(buf[0:n]); writeErr != nil {
-		panic(writeErr)
+	if c.WriteFile != nil {
+		if _, writeErr := c.ReadFile.Write(buf[0:n]); writeErr != nil {
+			panic(writeErr)
+		}
 	}
 	return
 }
 
 func (c *ReadWriteCloserLogger) Write(buf []byte) (n int, err error) {
 	n, err = c.RWC.Write(buf)
-	if _, writeErr := c.WriteFile.Write(buf[0:n]); writeErr != nil {
-		panic(writeErr)
+	if c.ReadFile != nil {
+		if _, writeErr := c.WriteFile.Write(buf[0:n]); writeErr != nil {
+			panic(writeErr)
+		}
 	}
 	return
 }
-func (c *ReadWriteCloserLogger) Close() error {
-	return c.RWC.Close()
+func (c *ReadWriteCloserLogger) Close() (err error) {
+	err = c.RWC.Close()
+	if err != nil {
+		return
+	}
+	if c.ReadFile != nil {
+		if err := c.ReadFile.Close(); err != nil {
+			panic(err)
+		}
+	}
+	if c.WriteFile != nil {
+		if err := c.WriteFile.Close(); err != nil {
+			panic(err)
+		}
+	}
+	return
 }
 
 type ChainedReader struct {