Enhancement/Fixes for the Overview function

README.md

@@ -3,6 +3,13 @@ nntp.go
 
 An NNTP (news) Client package for go (golang). Forked from [nntp-go](http://code.google.com/p/nntp-go/) to bring it up to date.
 
+Updates
+-------
+- added IHAVE command
+- use XOVER if OVER is unrecognized
+- set overview.Bytes to 0 if bytes value is empty
+- set overview.Lines to 0 if lines value is empty
+
 Example
 -------
 

go.mod

@@ -0,0 +1,3 @@
+module github.com/Tensai75/nntp
+
+go 1.16

nntp.go

@@ -12,7 +12,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net"
 	"net/http"
 	"sort"
@@ -117,7 +116,7 @@ func (r *bodyReader) Read(p []byte) (n int, err error) {
 }
 
 func (r *bodyReader) discard() error {
-	_, err := ioutil.ReadAll(r)
+	_, err := io.ReadAll(r)
 	return err
 }
 
@@ -207,8 +206,8 @@ func newConn(c net.Conn) (res *Conn, err error) {
 // make the connection.
 //
 // Example:
-//   conn, err := nntp.Dial("tcp", "my.news:nntp")
 //
+//	conn, err := nntp.Dial("tcp", "my.news:nntp")
 func Dial(network, addr string) (*Conn, error) {
 	c, err := net.Dial(network, addr)
 	if err != nil {
@@ -370,8 +369,17 @@ type MessageOverview struct {
 // Overview returns overviews of all messages in the current group with message number between
 // begin and end, inclusive.
 func (c *Conn) Overview(begin, end int) ([]MessageOverview, error) {
-	if _, _, err := c.cmd(224, "OVER %d-%d", begin, end); err != nil {
-		return nil, err
+	if code, _, err := c.cmd(224, "OVER %d-%d", begin, end); err != nil {
+		// if error is "500 Unknown Command" (correct response according to RFC 3977), or
+		// if error is "400 Unrecognized command" or (wrong response sent by newshositng, eweka, tweaknews and maybe others...)
+		// try the XOVER command
+		if code == 500 || code == 400 {
+			if _, _, err := c.cmd(224, "XOVER %d-%d", begin, end); err != nil {
+				return nil, err
+			}
+		} else {
+			return nil, err
+		}
 	}
 
 	lines, err := c.readStrings()
@@ -381,36 +389,71 @@ func (c *Conn) Overview(begin, end int) ([]MessageOverview, error) {
 
 	result := make([]MessageOverview, 0, len(lines))
 	for _, line := range lines {
-		overview := MessageOverview{}
-		ss := strings.SplitN(strings.TrimSpace(line), "\t", 9)
-		if len(ss) < 8 {
-			return nil, ProtocolError("short header listing line: " + line + strconv.Itoa(len(ss)))
-		}
-		overview.MessageNumber, err = strconv.Atoi(ss[0])
-		if err != nil {
-			return nil, ProtocolError("bad message number '" + ss[0] + "' in line: " + line)
-		}
-		overview.Subject = ss[1]
-		overview.From = ss[2]
-		overview.Date, err = parseDate(ss[3])
+		overview, err := ParseOverviewLine(line)
 		if err != nil {
-			// Inability to parse date is not fatal: the field in the message may be broken or missing.
-			overview.Date = time.Time{}
+			return nil, err
 		}
-		overview.MessageId = ss[4]
-		overview.References = strings.Split(ss[5], " ") // Message-Id's contain no spaces, so this is safe.
+		result = append(result, overview)
+	}
+	return result, nil
+}
+
+func ParseOverviewLine(line string) (MessageOverview, error) {
+	err := error(nil)
+	overview := MessageOverview{}
+	ss := strings.SplitN(strings.TrimSpace(line), "\t", 9)
+	if len(ss) < 8 {
+		return MessageOverview{}, ProtocolError("short header listing line: " + line + strconv.Itoa(len(ss)))
+	}
+	overview.MessageNumber, err = strconv.Atoi(ss[0])
+	if err != nil {
+		return MessageOverview{}, ProtocolError("bad message number '" + ss[0] + "' in line: " + line)
+	}
+	overview.Subject = ss[1]
+	overview.From = ss[2]
+	overview.Date, err = parseDate(ss[3])
+	if err != nil {
+		// Inability to parse date is not fatal: the field in the message may be broken or missing.
+		overview.Date = time.Time{}
+	}
+	overview.MessageId = ss[4]
+	overview.References = strings.Split(ss[5], " ") // Message-Id's contain no spaces, so this is safe.
+	if ss[6] == "" {
+		overview.Bytes = 0
+	} else {
 		overview.Bytes, err = strconv.Atoi(ss[6])
 		if err != nil {
-			return nil, ProtocolError("bad byte count '" + ss[6] + "'in line:" + line)
+			return MessageOverview{}, ProtocolError("bad byte count '" + ss[6] + "'in line:" + line)
 		}
+	}
+	if ss[7] == "" {
+		overview.Lines = 0
+	} else {
 		overview.Lines, err = strconv.Atoi(ss[7])
 		if err != nil {
-			return nil, ProtocolError("bad line count '" + ss[7] + "'in line:" + line)
+			return MessageOverview{}, ProtocolError("bad line count '" + ss[7] + "'in line:" + line)
 		}
-		overview.Extra = append([]string{}, ss[8:]...)
-		result = append(result, overview)
 	}
-	return result, nil
+	overview.Extra = append([]string{}, ss[8:]...)
+	return overview, nil
+}
+
+// Overview returns a reader for overviews of all messages in the current group with message number between
+// begin and end, inclusive.
+func (c *Conn) OverviewReader(begin, end int) (*bufio.Reader, error) {
+	if code, _, err := c.cmd(224, "OVER %d-%d", begin, end); err != nil {
+		// if error is "500 Unknown Command" (correct response according to RFC 3977), or
+		// if error is "400 Unrecognized command" or (wrong response sent by newshositng, eweka, tweaknews and maybe others...)
+		// try the XOVER command
+		if code == 500 || code == 400 {
+			if _, _, err := c.cmd(224, "XOVER %d-%d", begin, end); err != nil {
+				return nil, err
+			}
+		} else {
+			return nil, err
+		}
+	}
+	return c.r, nil
 }
 
 // parseGroups is used to parse a list of group states.
@@ -460,10 +503,9 @@ func (c *Conn) Date() (time.Time, error) {
 // List returns a list of groups present on the server.
 // Valid forms are:
 //
-//   List() - return active groups
-//   List(keyword) - return different kinds of information about groups
-//   List(keyword, pattern) - filter groups against a glob-like pattern called a wildmat
-//
+//	List() - return active groups
+//	List(keyword) - return different kinds of information about groups
+//	List(keyword, pattern) - filter groups against a glob-like pattern called a wildmat
 func (c *Conn) List(a ...string) ([]string, error) {
 	if len(a) > 2 {
 		return nil, ProtocolError("List only takes up to 2 arguments")
@@ -495,7 +537,7 @@ func (c *Conn) Group(group string) (number, low, high int, err error) {
 	}
 
 	var n [3]int
-	for i, _ := range n {
+	for i := range n {
 		c, e := strconv.Atoi(ss[i])
 		if e != nil {
 			err = ProtocolError("bad group response: " + line)
@@ -595,11 +637,8 @@ func (c *Conn) Body(id string) (io.Reader, error) {
 	return c.body(), nil
 }
 
-// RawPost reads a text-formatted article from r and posts it to the server.
-func (c *Conn) RawPost(r io.Reader) error {
-	if _, _, err := c.cmd(3, "POST"); err != nil {
-		return err
-	}
+// sendLines sends the lines of a text-formatted article from r to the server.
+func (c *Conn) sendLines(r io.Reader) error {
 	br := bufio.NewReader(r)
 	eof := false
 	for {
@@ -612,9 +651,7 @@ func (c *Conn) RawPost(r io.Reader) error {
 		if eof && len(line) == 0 {
 			break
 		}
-		if strings.HasSuffix(line, "\n") {
-			line = line[0 : len(line)-1]
-		}
+		line = strings.TrimSuffix(line, "\n")
 		var prefix string
 		if strings.HasPrefix(line, ".") {
 			prefix = "."
@@ -627,7 +664,17 @@ func (c *Conn) RawPost(r io.Reader) error {
 			break
 		}
 	}
+	return nil
+}
 
+// RawPost reads a text-formatted article from r and posts it to the server.
+func (c *Conn) RawPost(r io.Reader) error {
+	if _, _, err := c.cmd(3, "POST"); err != nil {
+		return err
+	}
+	if err := c.sendLines(r); err != nil {
+		return err
+	}
 	if _, _, err := c.cmd(240, "."); err != nil {
 		return err
 	}
@@ -639,8 +686,28 @@ func (c *Conn) Post(a *Article) error {
 	return c.RawPost(&articleReader{a: a})
 }
 
+// RawIHave reads a text-formatted article from r and presents it to the server with the IHAVE command.
+func (c *Conn) RawIHave(r io.Reader) error {
+	if _, _, err := c.cmd(3, "IHAVE"); err != nil {
+		return err
+	}
+	if err := c.sendLines(r); err != nil {
+		return err
+	}
+	if _, _, err := c.cmd(235, "."); err != nil {
+		return err
+	}
+	return nil
+}
+
+// IHave presents an article to the server with the IHAVE command.
+func (c *Conn) IHave(a *Article) error {
+	return c.RawIHave(&articleReader{a: a})
+}
+
 // Quit sends the QUIT command and closes the connection to the server.
 func (c *Conn) Quit() error {
+	c.r.Discard(c.r.Buffered())
 	_, _, err := c.cmd(0, "QUIT")
 	c.conn.Close()
 	c.close = true
@@ -699,7 +766,7 @@ func readKeyValue(b *bufio.Reader) (key, value string, err error) {
 	}
 
 	key = string(line[0:i])
-	if strings.Index(key, " ") >= 0 {
+	if strings.Contains(key, " ") {
 		// Key field has space - no good.
 		goto Malformed
 	}

nntp_test.go

@@ -9,7 +9,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"strings"
 	"testing"
 	"time"
@@ -86,7 +85,7 @@ func TestBasics(t *testing.T) {
 	if err != nil {
 		t.Fatal("should be able to fetch the low article: " + err.Error())
 	}
-	body, err := ioutil.ReadAll(a.Body)
+	body, err := io.ReadAll(a.Body)
 	if err != nil {
 		t.Fatal("error reading reader: " + err.Error())
 	}
@@ -142,7 +141,7 @@ Body.
 	if err != nil {
 		t.Fatal("should be able to fetch the low article body" + err.Error())
 	}
-	if _, err = ioutil.ReadAll(r); err != nil {
+	if _, err = io.ReadAll(r); err != nil {
 		t.Fatal("error reading reader: " + err.Error())
 	}