From c6b898ea9ab372c58c59658c2acf17ea831d71db Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Tue, 11 Jun 2019 10:53:43 +0200
Subject: [PATCH] nsscash: support longer lines in passwd/group files

bufio.Scanner has an internal limit on the maximum token (= line)
length. We want to support larger lines in the future.
---
 group.go  | 19 ++++++++++++-------
 passwd.go | 20 +++++++++++---------
 2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/group.go b/group.go
index 0ad8671..214f914 100644
--- a/group.go
+++ b/group.go
@@ -62,9 +62,15 @@ func toKey(g Group) GroupKey {
 func ParseGroups(r io.Reader) ([]Group, error) {
 	var res []Group
 
-	s := bufio.NewScanner(r)
-	for s.Scan() {
-		t := s.Text()
+	s := bufio.NewReader(r)
+	for {
+		t, err := s.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
 
 		x := strings.Split(t, ":")
 		if len(x) != 4 {
@@ -76,6 +82,9 @@ func ParseGroups(r io.Reader) ([]Group, error) {
 			return nil, errors.Wrapf(err, "invalid gid in line %q", t)
 		}
 
+		// ReadString() contains the delimiter
+		x[3] = strings.TrimSuffix(x[3], "\n")
+
 		var members []string
 		// No members must result in empty slice, not slice with the
 		// empty string
@@ -89,10 +98,6 @@ func ParseGroups(r io.Reader) ([]Group, error) {
 			Members: members,
 		})
 	}
-	err := s.Err()
-	if err != nil {
-		return nil, err
-	}
 
 	return res, nil
 }
diff --git a/passwd.go b/passwd.go
index 07a62d8..2698765 100644
--- a/passwd.go
+++ b/passwd.go
@@ -48,9 +48,15 @@ type Passwd struct {
 func ParsePasswds(r io.Reader) ([]Passwd, error) {
 	var res []Passwd
 
-	s := bufio.NewScanner(r)
-	for s.Scan() {
-		t := s.Text()
+	s := bufio.NewReader(r)
+	for {
+		t, err := s.ReadString('\n')
+		if err != nil {
+			if err == io.EOF {
+				break
+			}
+			return nil, err
+		}
 
 		x := strings.Split(t, ":")
 		if len(x) != 7 {
@@ -73,14 +79,10 @@ func ParsePasswds(r io.Reader) ([]Passwd, error) {
 			Gid:    gid,
 			Gecos:  x[4],
 			Dir:    x[5],
-			Shell:  x[6],
+			// ReadString() contains the delimiter
+			Shell: strings.TrimSuffix(x[6], "\n"),
 		})
 	}
-	err := s.Err()
-	if err != nil {
-		return nil, err
-	}
-
 	return res, nil
 }
 
-- 
2.43.2