From 183a5ec12e2eeb0efa72ad4ab17be9844666f9bb Mon Sep 17 00:00:00 2001
From: Shubham Sinha <shubham.sinha@walmartlabs.com>
Date: Wed, 2 Oct 2019 14:07:12 +0530
Subject: [PATCH 1/4] added checks for logger not being attached to the entry
 type

---
 entry.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/entry.go b/entry.go
index 63e25583c..bc29b6e19 100644
--- a/entry.go
+++ b/entry.go
@@ -3,6 +3,7 @@ package logrus
 import (
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"os"
 	"reflect"
@@ -30,6 +31,10 @@ const (
 	knownLogrusFrames  int = 4
 )
 
+var (
+	loggerNotAttached = errors.New("entry not attached to any logger")
+)
+
 func init() {
 	bufferPool = &sync.Pool{
 		New: func() interface{} {
@@ -88,6 +93,10 @@ func NewEntry(logger *Logger) *Entry {
 // Returns the string representation from the reader and ultimately the
 // formatter.
 func (entry *Entry) String() (string, error) {
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		return "", loggerNotAttached
+	}
 	serialized, err := entry.Logger.Formatter.Format(entry)
 	if err != nil {
 		return "", err
@@ -241,6 +250,11 @@ func (entry Entry) log(level Level, msg string) {
 }
 
 func (entry *Entry) fireHooks() {
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	entry.Logger.mu.Lock()
 	defer entry.Logger.mu.Unlock()
 	err := entry.Logger.Hooks.Fire(entry.Level, entry)
@@ -250,6 +264,11 @@ func (entry *Entry) fireHooks() {
 }
 
 func (entry *Entry) write() {
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	entry.Logger.mu.Lock()
 	defer entry.Logger.mu.Unlock()
 	serialized, err := entry.Logger.Formatter.Format(entry)
@@ -345,6 +364,11 @@ func (entry *Entry) Errorf(format string, args ...interface{}) {
 
 func (entry *Entry) Fatalf(format string, args ...interface{}) {
 	entry.Logf(FatalLevel, format, args...)
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	entry.Logger.Exit(1)
 }
 
@@ -355,6 +379,11 @@ func (entry *Entry) Panicf(format string, args ...interface{}) {
 // Entry Println family functions
 
 func (entry *Entry) Logln(level Level, args ...interface{}) {
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	if entry.Logger.IsLevelEnabled(level) {
 		entry.Log(level, entry.sprintlnn(args...))
 	}

From 2433a5a461c4e94b44338a0212f7e548950a3f4d Mon Sep 17 00:00:00 2001
From: Shubham Sinha <shubham.sinha@walmartlabs.com>
Date: Wed, 2 Oct 2019 15:20:52 +0530
Subject: [PATCH 2/4] added checks for logger not being attached to the entry
 type

---
 entry.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/entry.go b/entry.go
index bc29b6e19..4200031fb 100644
--- a/entry.go
+++ b/entry.go
@@ -283,6 +283,11 @@ func (entry *Entry) write() {
 }
 
 func (entry *Entry) Log(level Level, args ...interface{}) {
+	// add a check for logger being nil because entry is exposed
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	if entry.Logger.IsLevelEnabled(level) {
 		entry.log(level, fmt.Sprint(args...))
 	}

From 50f9d42676deace5be55a8fe026f3fca6f1a3a62 Mon Sep 17 00:00:00 2001
From: Shubham Sinha <shubham.sinha@walmartlabs.com>
Date: Wed, 9 Oct 2019 22:35:33 +0530
Subject: [PATCH 3/4] added test cases for entry logger not attached

---
 entry.go      |  5 -----
 entry_test.go | 18 +++++++++++++++++-
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/entry.go b/entry.go
index 4200031fb..6de30e475 100644
--- a/entry.go
+++ b/entry.go
@@ -264,11 +264,6 @@ func (entry *Entry) fireHooks() {
 }
 
 func (entry *Entry) write() {
-	// add a check for logger being nil because entry is exposed
-	if entry.Logger == nil {
-		fmt.Fprintf(os.Stderr, "Logger not attached\n")
-		return
-	}
 	entry.Logger.mu.Lock()
 	defer entry.Logger.mu.Unlock()
 	serialized, err := entry.Logger.Formatter.Format(entry)
diff --git a/entry_test.go b/entry_test.go
index f764085ef..b538ecca2 100644
--- a/entry_test.go
+++ b/entry_test.go
@@ -166,4 +166,20 @@ func TestEntryLogfLevel(t *testing.T) {
 
 	entry.Logf(WarnLevel, "%s", "warn")
 	assert.Contains(t, buffer.String(), "warn", )
-}
\ No newline at end of file
+}
+
+func TestEntryLoggerNotAttached(t *testing.T) {
+	assert := assert.New(t)
+
+	e := Entry{}
+
+	_, err := e.String()
+	assert.NotNil(err)
+
+	e.fireHooks()
+
+	e.Log(InfoLevel)
+	e.Logf(InfoLevel, "")
+	e.Fatalf("")
+	e.Logln(InfoLevel)
+}

From abc679f8456b1f33baaa89a9a3cf13ea44080798 Mon Sep 17 00:00:00 2001
From: Shubham Sinha <shubham.sinha@walmartlabs.com>
Date: Wed, 9 Oct 2019 22:40:27 +0530
Subject: [PATCH 4/4] added checks for logger not being attached to the entry
 type

---
 entry.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/entry.go b/entry.go
index 6de30e475..ab0800a64 100644
--- a/entry.go
+++ b/entry.go
@@ -329,6 +329,10 @@ func (entry *Entry) Panic(args ...interface{}) {
 // Entry Printf family functions
 
 func (entry *Entry) Logf(level Level, format string, args ...interface{}) {
+	if entry.Logger == nil {
+		fmt.Fprintf(os.Stderr, "Logger not attached\n")
+		return
+	}
 	if entry.Logger.IsLevelEnabled(level) {
 		entry.Log(level, fmt.Sprintf(format, args...))
 	}