user: skip malformed lines

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

user/user.go

@@ -62,6 +62,7 @@ func parseLine(line []byte, v ...any) error {
 
 func parseParts(parts [][]byte, v ...any) error {
 	if len(parts) == 0 {
+		// TODO(thaJeztah); do we need an "ok" return so that we can skip these in loops?
 		return nil
 	}
 
@@ -151,7 +152,9 @@ func ParsePasswdFilter(r io.Reader, filter func(User) bool) ([]User, error) {
 		//  adm:x:3:4:adm:/var/adm:/bin/false
 		p := User{}
 		if err := parseLine(line, &p.Name, &p.Pass, &p.Uid, &p.Gid, &p.Gecos, &p.Home, &p.Shell); err != nil {
-			return nil, err
+			// Skip malformed lines, and don't consider them.
+			// return nil, fmt.Errorf("invalid line (%q): %w", string(line), err)
+			continue
 		}
 
 		if filter == nil || filter(p) {
@@ -212,7 +215,9 @@ func ParseGroupFilter(r io.Reader, filter func(Group) bool) ([]Group, error) {
 		//  adm:x:4:root,adm,daemon
 		p := Group{}
 		if err := parseLine(line, &p.Name, &p.Pass, &p.Gid, &p.List); err != nil {
-			return nil, err
+			// Skip malformed lines, and don't consider them.
+			// return nil, fmt.Errorf("invalid line (%q): %w", string(line), err)
+			continue
 		}
 
 		if filter == nil || filter(p) {
@@ -559,6 +564,8 @@ func ParseSubIDFilter(r io.Reader, filter func(SubID) bool) ([]SubID, error) {
 		// see: man 5 subuid
 		p := SubID{}
 		if err := parseLine(line, &p.Name, &p.SubID, &p.Count); err != nil {
+			// Skip malformed lines, and don't consider them.
+			// return nil, fmt.Errorf("invalid line (%q): %w", string(line), err)
 			return nil, err
 		}
 
@@ -609,7 +616,9 @@ func ParseIDMapFilter(r io.Reader, filter func(IDMap) bool) ([]IDMap, error) {
 		// see: man 7 user_namespaces
 		p := IDMap{}
 		if err := parseParts(bytes.Fields(line), &p.ID, &p.ParentID, &p.Count); err != nil {
-			return nil, err
+			// Skip malformed lines, and don't consider them.
+			// return nil, fmt.Errorf("invalid line (%q): %w", string(line), err)
+			continue
 		}
 
 		if filter == nil || filter(p) {