Update vendor/

vendor/github.com/emersion/go-message/multipart.go

@@ -0,0 +1,110 @@
+package message
+
+import (
+	"io"
+	"mime/multipart"
+)
+
+// MultipartReader is an iterator over parts in a MIME multipart body.
+type MultipartReader interface {
+	io.Closer
+
+	// NextPart returns the next part in the multipart or an error. When there are
+	// no more parts, the error io.EOF is returned.
+	//
+	// Entity.Body must be read completely before the next call to NextPart,
+	// otherwise it will be discarded.
+	NextPart() (*Entity, error)
+}
+
+type multipartReader struct {
+	r *multipart.Reader
+}
+
+// NextPart implements MultipartReader.
+func (r *multipartReader) NextPart() (*Entity, error) {
+	p, err := r.r.NextPart()
+	if err != nil {
+		return nil, err
+	}
+	return New(Header(p.Header), p)
+}
+
+// Close implements io.Closer.
+func (r *multipartReader) Close() error {
+	return nil
+}
+
+type multipartBody struct {
+	header Header
+	parts  []*Entity
+
+	r *io.PipeReader
+	w *Writer
+
+	i int
+}
+
+// Read implements io.Reader.
+func (m *multipartBody) Read(p []byte) (n int, err error) {
+	if m.r == nil {
+		r, w := io.Pipe()
+		m.r = r
+		m.w = newWriter(w, m.header)
+
+		// Prevent calls to NextPart to succeed
+		m.i = len(m.parts)
+
+		go func() {
+			if err := m.writeBodyTo(m.w); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			if err := m.w.Close(); err != nil {
+				w.CloseWithError(err)
+				return
+			}
+
+			w.Close()
+		}()
+	}
+
+	return m.r.Read(p)
+}
+
+// Close implements io.Closer.
+func (m *multipartBody) Close() error {
+	if m.r != nil {
+		m.r.Close()
+	}
+	return nil
+}
+
+// NextPart implements MultipartReader.
+func (m *multipartBody) NextPart() (*Entity, error) {
+	if m.i >= len(m.parts) {
+		return nil, io.EOF
+	}
+
+	part := m.parts[m.i]
+	m.i++
+	return part, nil
+}
+
+func (m *multipartBody) writeBodyTo(w *Writer) error {
+	for _, p := range m.parts {
+		pw, err := w.CreatePart(p.Header)
+		if err != nil {
+			return err
+		}
+
+		if err := p.writeBodyTo(pw); err != nil {
+			return err
+		}
+		if err := pw.Close(); err != nil {
+			return err
+		}
+	}
+	return nil
+}