From 087556715f372d60947ceea230cdf7cd1af91313 Mon Sep 17 00:00:00 2001
From: Abin Simon <mail@meain.io>
Date: Tue, 12 Mar 2024 12:05:24 +0530
Subject: [PATCH] Add support for HeaderEncodingNone

---
 email.go       |  9 +++++----
 header.go      | 31 ++++++-------------------------
 header_test.go |  4 ++--
 3 files changed, 13 insertions(+), 31 deletions(-)

diff --git a/email.go b/email.go
index 9af82f4..0a109ce 100644
--- a/email.go
+++ b/email.go
@@ -115,7 +115,7 @@ type headerEncoding int
 
 const (
 	// HeaderEncodingNone turns off encoding on the message headers
-	HeaderEncodingNone encoding = iota
+	HeaderEncodingNone headerEncoding = iota
 
 	// TODO: Add Base64 encoding
 	// HeaderEncodingBase64 sets the message header encoding to base64
@@ -222,9 +222,10 @@ func (dsn DSN) String() string {
 // NewMSG creates a new email. It uses UTF-8 by default. All charsets: http://webcheatsheet.com/HTML/character_sets_list.php
 func NewMSG() *Email {
 	email := &Email{
-		headers:  make(textproto.MIMEHeader),
-		Charset:  "UTF-8",
-		Encoding: EncodingQuotedPrintable,
+		headers:        make(textproto.MIMEHeader),
+		Charset:        "UTF-8",
+		Encoding:       EncodingQuotedPrintable,
+		HeaderEncoding: HeaderEncodingQ,
 	}
 
 	email.AddHeader("MIME-Version", "1.0")
diff --git a/header.go b/header.go
index 59acda6..923be5b 100644
--- a/header.go
+++ b/header.go
@@ -27,8 +27,9 @@ func newEncoder(w io.Writer, c string, encoding headerEncoding, u int) *encoder
 	return &encoder{bufio.NewWriter(w), strings.ToUpper(c), encoding, u}
 }
 
-// encode encodes p using the "Q" encoding and writes it to the underlying
-// io.Writer. It limits line length to 75 characters.
+// encode encodes p using the encoding scheme specified in e
+// If all chars are printable ascii chars, no encoding is performed.
+// Limits line length to 75 characters and folds lines as necessary.
 func (e *encoder) encode(p []byte) (n int, err error) {
 	var output bytes.Buffer
 	allPrintable := true
@@ -49,7 +50,7 @@ func (e *encoder) encode(p []byte) (n int, err error) {
 	}
 
 	// all characters are printable. just do line folding
-	if allPrintable {
+	if allPrintable || e.encoding == HeaderEncodingNone {
 		text := string(p)
 		words := strings.Split(text, " ")
 
@@ -58,10 +59,6 @@ func (e *encoder) encode(p []byte) (n int, err error) {
 
 		// split the line where necessary
 		for _, word := range words {
-			/*fmt.Println("Current Line:",lineBuffer)
-			fmt.Println("Here: Max:", maxLineLength ,"Buffer Length:", len(lineBuffer), "Used Chars:", e.usedChars, "Length Encoded Char:",len(word))
-			fmt.Println("----------")*/
-
 			newWord := ""
 			if !firstWord {
 				newWord += " "
@@ -69,7 +66,7 @@ func (e *encoder) encode(p []byte) (n int, err error) {
 			newWord += word
 
 			// check line length
-			if (e.usedChars+len(lineBuffer)+len(newWord) /*+len(" ")+len(word)*/) > maxLineLength && (lineBuffer != "" || e.usedChars != 0) {
+			if (e.usedChars+len(lineBuffer)+len(newWord)) > maxLineLength && (lineBuffer != "" || e.usedChars != 0) {
 				output.WriteString(lineBuffer + "\r\n")
 
 				// first word on newline needs a space in front
@@ -79,29 +76,17 @@ func (e *encoder) encode(p []byte) (n int, err error) {
 					lineBuffer = " "
 				}
 
-				//firstLine = false
-				//firstWord = true
 				// reset since not on the first line anymore
 				e.usedChars = 0
 			}
 
-			/*if !firstWord {
-				lineBuffer += " "
-			}*/
-
 			lineBuffer += newWord /*word*/
-
 			firstWord = false
-
-			// reset since not on the first line anymore
-			/*if !firstLine {
-				e.usedChars = 0
-			}*/
 		}
 
 		output.WriteString(lineBuffer)
-
 	} else {
+		// else block can only be HeaderEncodingQ as of now
 		firstLine := true
 
 		// A single encoded word can not be longer than 75 characters
@@ -118,10 +103,6 @@ func (e *encoder) encode(p []byte) (n int, err error) {
 			// encode the character
 			encodedChar, runeLength := encode(p, i)
 
-			/*fmt.Println("Current Line:",lineBuffer)
-			fmt.Println("Here: Max:", maxLineLength ,"Buffer Length:", len(lineBuffer), "Used Chars:", e.usedChars, "Length Encoded Char:",len(encodedChar))
-			fmt.Println("----------")*/
-
 			// Check line length
 			if len(lineBuffer)+e.usedChars+len(encodedChar) > (maxLineLength - len(wordEnd)) {
 				output.WriteString(lineBuffer + wordEnd + "\r\n")
diff --git a/header_test.go b/header_test.go
index 1806c2f..a2c2c78 100644
--- a/header_test.go
+++ b/header_test.go
@@ -13,11 +13,11 @@ func TestWriter(t *testing.T) {
 
 func testWriter(t *testing.T, binary bool) {
 	utf8 := "utf-8"
-	qp := EncodingQuotedPrintable
+	qp := HeaderEncodingQ
 
 	tests := []struct {
 		charset   string
-		encoding  encoding
+		encoding  headerEncoding
 		usedChars int
 		in, want  string
 	}{