Update from upstream

.build.yml

@@ -1,4 +1,4 @@
-image: alpine/edge
+image: alpine/latest
 packages:
   - go
 sources:
@@ -15,3 +15,6 @@ tasks:
   - coverage: |
       cd go-message
       go tool cover -html=coverage.txt -o ~/coverage.html
+  - gofmt: |
+      cd go-message
+      test -z $(gofmt -l .)

README.md

@@ -1,7 +1,6 @@
 # go-message
 
-[![godocs.io](https://godocs.io/github.com/emersion/go-message?status.svg)](https://godocs.io/github.com/emersion/go-message)
-[![builds.sr.ht status](https://builds.sr.ht/~emersion/go-message/commits.svg)](https://builds.sr.ht/~emersion/go-message/commits?)
+[![Go Reference](https://pkg.go.dev/badge/github.com/emersion/go-message.svg)](https://pkg.go.dev/github.com/emersion/go-message)
 
 A Go library for the Internet Message Format. It implements:
 

charset/charset.go

@@ -14,6 +14,7 @@ import (
 	"golang.org/x/text/encoding/charmap"
 	"golang.org/x/text/encoding/htmlindex"
 	"golang.org/x/text/encoding/ianaindex"
+	"golang.org/x/text/encoding/unicode"
 )
 
 // Quirks table for charsets not handled by ianaindex
@@ -24,6 +25,7 @@ import (
 // https://www.iana.org/assignments/character-sets/character-sets.xhtml
 var charsets = map[string]encoding.Encoding{
 	"ansi_x3.110-1983": charmap.ISO8859_1, // see RFC 1345 page 62, mostly superset of ISO 8859-1
+	"x-utf_8j":         unicode.UTF8,      // alias for UTF-8, see https://icu4c-demos.unicode.org/icu-bin/convexp?s=ALL
 }
 
 func init() {

encoding.go

@@ -1,14 +1,13 @@
 package message
 
 import (
+	"bytes"
 	"encoding/base64"
 	"errors"
 	"fmt"
 	"io"
 	"mime/quotedprintable"
 	"strings"
-
-	"github.com/emersion/go-textwrapper"
 )
 
 type UnknownEncodingError struct {
@@ -57,9 +56,9 @@ func encodingWriter(enc string, w io.Writer) (io.WriteCloser, error) {
 	case "quoted-printable":
 		wc = quotedprintable.NewWriter(w)
 	case "base64":
-		wc = base64.NewEncoder(base64.StdEncoding, textwrapper.NewRFC822(w))
+		wc = base64.NewEncoder(base64.StdEncoding, &lineWrapper{w: w, maxLineLen: 76})
 	case "7bit", "8bit":
-		wc = nopCloser{textwrapper.New(w, "\r\n", 1000)}
+		wc = nopCloser{&lineWrapper{w: w, maxLineLen: 998}}
 	case "binary", "":
 		wc = nopCloser{w}
 	default:
@@ -86,3 +85,71 @@ func (r *whitespaceReplacingReader) Read(p []byte) (int, error) {
 
 	return n, err
 }
+
+type lineWrapper struct {
+	w          io.Writer
+	maxLineLen int
+
+	curLineLen int
+	cr         bool
+}
+
+func (w *lineWrapper) Write(b []byte) (int, error) {
+	var written int
+	for len(b) > 0 {
+		var l []byte
+		l, b = cutLine(b, w.maxLineLen-w.curLineLen)
+
+		lf := bytes.HasSuffix(l, []byte("\n"))
+		l = bytes.TrimSuffix(l, []byte("\n"))
+
+		n, err := w.w.Write(l)
+		if err != nil {
+			return written, err
+		}
+		written += n
+
+		cr := bytes.HasSuffix(l, []byte("\r"))
+		if len(l) == 0 {
+			cr = w.cr
+		}
+
+		if !lf && len(b) == 0 {
+			w.curLineLen += len(l)
+			w.cr = cr
+			break
+		}
+		w.curLineLen = 0
+
+		ending := []byte("\r\n")
+		if cr {
+			ending = []byte("\n")
+		}
+		_, err = w.w.Write(ending)
+		if err != nil {
+			return written, err
+		}
+		// If the written `\n` was part of the input bytes slice, then account for it.
+		if lf {
+			written++
+		}
+		w.cr = false
+	}
+
+	return written, nil
+}
+
+func cutLine(b []byte, max int) ([]byte, []byte) {
+	for i := 0; i < len(b); i++ {
+		if b[i] == '\r' && i == max {
+			continue
+		}
+		if b[i] == '\n' {
+			return b[:i+1], b[i+1:]
+		}
+		if i >= max {
+			return b[:i], b[i:]
+		}
+	}
+	return b, nil
+}

encoding_test.go

@@ -71,3 +71,99 @@ func TestEncode(t *testing.T) {
 		}
 	}
 }
+
+var lineWrapperTests = []struct {
+	name    string
+	in, out string
+}{
+	{
+		name: "empty",
+		in:   "",
+		out:  "",
+	},
+	{
+		name: "oneLine",
+		in:   "ab",
+		out:  "ab",
+	},
+	{
+		name: "oneLineMax",
+		in:   "abc",
+		out:  "abc",
+	},
+	{
+		name: "twoLines",
+		in:   "abcde",
+		out:  "abc\r\nde",
+	},
+	{
+		name: "twoLinesMax",
+		in:   "abcdef",
+		out:  "abc\r\ndef",
+	},
+	{
+		name: "threeLines",
+		in:   "abcdefhi",
+		out:  "abc\r\ndef\r\nhi",
+	},
+	{
+		name: "wrappedMiss",
+		in:   "abcd\nef",
+		out:  "abc\r\nd\r\nef",
+	},
+	{
+		name: "wrappedLF",
+		in:   "abc\ndef\nhij",
+		out:  "abc\r\ndef\r\nhij",
+	},
+	{
+		name: "wrappedCRLF",
+		in:   "abc\r\ndef\r\nhij",
+		out:  "abc\r\ndef\r\nhij",
+	},
+	{
+		name: "trailingCRLF",
+		in:   "a\r\n",
+		out:  "a\r\n",
+	},
+	{
+		name: "cr",
+		in:   "\r\r\r\r\r",
+		out:  "\r\r\r\r\n\r",
+	},
+}
+
+func TestLineWrapper(t *testing.T) {
+	for _, tc := range lineWrapperTests {
+		t.Run(tc.name, func(t *testing.T) {
+			var sb strings.Builder
+			w := &lineWrapper{w: &sb, maxLineLen: 3}
+			if _, err := io.WriteString(w, tc.in); err != nil {
+				t.Fatalf("WriteString() = %v", err)
+			}
+			if s := sb.String(); s != tc.out {
+				t.Errorf("got %q, want %q", s, tc.out)
+			}
+		})
+
+		t.Run(tc.name+"/bytePerByte", func(t *testing.T) {
+			var sb strings.Builder
+			w := &lineWrapper{w: &sb, maxLineLen: 3}
+			if err := writeStringBytePerByte(w, tc.in); err != nil {
+				t.Fatalf("writeStringBytePerByte() = %v", err)
+			}
+			if s := sb.String(); s != tc.out {
+				t.Errorf("got %q, want %q", s, tc.out)
+			}
+		})
+	}
+}
+
+func writeStringBytePerByte(w io.Writer, s string) error {
+	for i := 0; i < len(s); i++ {
+		if _, err := w.Write([]byte{s[i]}); err != nil {
+			return err
+		}
+	}
+	return nil
+}

entity.go

@@ -12,6 +12,9 @@ import (
 
 // An Entity is either a whole message or a one of the parts in the body of a
 // multipart entity.
+//
+// An Entity can only be consumed once: after its body is read, it can't be
+// used anymore.
 type Entity struct {
 	Header Header    // The entity's header.
 	Body   io.Reader // The decoded entity's body.
@@ -187,9 +190,13 @@ func (e *Entity) WriteTo(w io.Writer) error {
 	if err != nil {
 		return err
 	}
-	defer ew.Close()
 
-	return e.writeBodyTo(ew)
+	if err := e.writeBodyTo(ew); err != nil {
+		ew.Close()
+		return err
+	}
+
+	return ew.Close()
 }
 
 // WalkFunc is the type of the function called for each part visited by Walk.

go.mod

@@ -2,7 +2,4 @@ module github.com/mirrorweb/go-message
 
 go 1.14
 
-require (
-	github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594
-	golang.org/x/text v0.3.7
-)
+require golang.org/x/text v0.14.0

go.sum

@@ -1,5 +1,32 @@
-github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594 h1:IbFBtwoTQyw0fIM5xv1HF+Y+3ZijDR839WMulgxCcUY=
-github.com/emersion/go-textwrapper v0.0.0-20200911093747-65d896831594/go.mod h1:aqO8z8wPrjkscevZJFVE1wXJrLpC5LtJG7fqLOsPb2U=
-golang.org/x/text v0.3.7 h1:olpwvP2KacW1ZWvsR7uQhoyTYvKAupfQrRGBFM352Gk=
+github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
+golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug+ECip1KBveYUHfp+8e9klMJ9c=
+golang.org/x/net v0.6.0/go.mod h1:2Tu9+aMcznHK/AK1HMvgo6xiTLG5rD5rZLDS+rp2Bjs=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
+golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
+golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
+golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

header.go

@@ -33,12 +33,16 @@ type HeaderFields interface {
 	// charset is decoded to UTF-8. If the header field's charset is unknown,
 	// the raw field value is returned and the error verifies IsUnknownCharset.
 	Text() (string, error)
+
+	headerFields()
 }
 
 type headerFields struct {
 	textproto.HeaderFields
 }
 
+func (*headerFields) headerFields() {}
+
 func (hf *headerFields) Text() (string, error) {
 	return decodeHeader(hf.Value())
 }

mail/attachment.go

@@ -9,6 +9,10 @@ type AttachmentHeader struct {
 	message.Header
 }
 
+var _ PartHeader = (*AttachmentHeader)(nil)
+
+func (*AttachmentHeader) partHeader() {}
+
 // Filename parses the attachment's filename.
 func (h *AttachmentHeader) Filename() (string, error) {
 	_, params, err := h.ContentDisposition()

mail/header.go

@@ -198,9 +198,9 @@ func (p *headerParser) parseMsgID() (string, error) {
 		right, err = p.parseNoFoldLiteral()
 	} else {
 		right, err = p.parseAtomText(true)
-		if err != nil {
-			return "", err
-		}
+	}
+	if err != nil {
+		return "", err
 	}
 
 	if !p.consume('>') {
@@ -253,14 +253,23 @@ func (h *Header) SetAddressList(key string, addrs []*Address) {
 	}
 }
 
-// Date parses the Date header field.
+// Date parses the Date header field. If the header field is missing, it
+// returns the zero time.
 func (h *Header) Date() (time.Time, error) {
-	return mail.ParseDate(h.Get("Date"))
+	v := h.Get("Date")
+	if v == "" {
+		return time.Time{}, nil
+	}
+	return mail.ParseDate(v)
 }
 
 // SetDate formats the Date header field.
 func (h *Header) SetDate(t time.Time) {
-	h.Set("Date", t.Format(dateLayout))
+	if !t.IsZero() {
+		h.Set("Date", t.Format(dateLayout))
+	} else {
+		h.Del("Date")
+	}
 }
 
 // Subject parses the Subject header field. If there is an error, the raw field
@@ -350,7 +359,11 @@ func base36(input uint64) string {
 // SetMessageID sets the Message-ID field. id is the message identifier,
 // without the angle brackets.
 func (h *Header) SetMessageID(id string) {
-	h.Set("Message-Id", "<"+id+">")
+	if id != "" {
+		h.Set("Message-Id", "<"+id+">")
+	} else {
+		h.Del("Message-Id")
+	}
 }
 
 // SetMsgIDList formats a list of message identifiers. Message identifiers