fixup! [webseed] Add a custom URL encoder for webseeds

client.go

@@ -1326,7 +1326,7 @@ func (t *Torrent) MergeSpec(spec *TorrentSpec) error {
 	defer cl.unlock()
 	t.initialPieceCheckDisabled = spec.DisableInitialPieceCheck
 	for _, url := range spec.Webseeds {
-		t.addWebSeed(url, spec.EncodeWebSeedUrl)
+		t.addWebSeed(url, spec.DefaultWebseedEscapePath)
 	}
 	for _, peerAddr := range spec.PeerAddrs {
 		t.addPeer(PeerInfo{

spec.go

@@ -6,6 +6,7 @@ import (
 	"github.com/anacrolix/torrent/metainfo"
 	pp "github.com/anacrolix/torrent/peer_protocol"
 	"github.com/anacrolix/torrent/storage"
+	"github.com/anacrolix/torrent/webseed"
 )
 
 // Specifies a new torrent for adding to a client, or additions to an existing Torrent. There are
@@ -39,7 +40,7 @@ type TorrentSpec struct {
 
 	// Custom encoder for webseed URLs
 	// Leave nil to use the default (url.QueryEscape)
-	EncodeWebSeedUrl func(string) string
+	DefaultWebseedEscapePath webseed.PathEscaper
 }
 
 func TorrentSpecFromMagnetUri(uri string) (spec *TorrentSpec, err error) {

torrent.go

@@ -2350,28 +2350,30 @@ func (t *Torrent) callbacks() *Callbacks {
 	return &t.cl.config.Callbacks
 }
 
-type AddWebSeedsOptions struct {
+type AddWebseedsOpt func() *AddWebseedOpts
+
+type AddWebseedOpts struct {
 	// Custom encoder for webseed URLs
 	// Leave nil to use the default (url.QueryEscape)
-	EncodeUrl func(string) string
+	PathEscaper webseed.PathEscaper
 }
 
 
 // Add web seeds to the torrent.
-// If AddWebSeedsOptions is not nil, only the first one is used.
+// If opt is not nil, only the first one is used.
-func (t *Torrent) AddWebSeeds(urls []string, opts ...AddWebSeedsOptions) {
+func (t *Torrent) AddWebSeeds(urls []string, opt ...AddWebseedsOpt) {
 	t.cl.lock()
 	defer t.cl.unlock()
 	for _, u := range urls {
-		if opts == nil {
+		if opt == nil {
 			t.addWebSeed(u, nil)
 		} else {
-			t.addWebSeed(u, opts[0].EncodeUrl)
+			t.addWebSeed(u, opt[0]().PathEscaper)
 		}
 	}
 }
 
-func (t *Torrent) addWebSeed(url string, encodeUrl func(string) string) {
+func (t *Torrent) addWebSeed(url string, pathEscaper webseed.PathEscaper) {
 	if t.cl.config.DisableWebseeds {
 		return
 	}
@@ -2408,7 +2410,7 @@ func (t *Torrent) addWebSeed(url string, encodeUrl func(string) string) {
 					r: r,
 				}
 			},
-			EncodeUrl: encodeUrl,
+			PathEscaper: pathEscaper,
 		},
 		activeRequests: make(map[Request]webseed.Request, maxRequests),
 		maxRequests:    maxRequests,

webseed/client.go

@@ -57,7 +57,7 @@ type Client struct {
 	// private in the future, if Client ever starts removing pieces.
 	Pieces              roaring.Bitmap
 	ResponseBodyWrapper ResponseBodyWrapper
-	EncodeUrl           func(string) string
+	PathEscaper         PathEscaper
 }
 
 type ResponseBodyWrapper func(io.Reader) io.Reader
@@ -82,9 +82,9 @@ func (ws *Client) NewRequest(r RequestSpec) Request {
 	ctx, cancel := context.WithCancel(context.Background())
 	var requestParts []requestPart
 	if !ws.fileIndex.Locate(r, func(i int, e segments.Extent) bool {
-		req, err := NewRequestWithCustomUrlEncoding(
+		req, err := NewRequestWithOpts(
 			ws.Url, i, ws.info, e.Start, e.Length,
-			ws.EncodeUrl,
+			ws.PathEscaper,
 		)
 		if err != nil {
 			panic(err)

webseed/request.go

@@ -10,58 +10,70 @@ import (
 	"github.com/anacrolix/torrent/metainfo"
 )
 
+type PathEscaper func(pathComps []string) string
+
 // Escapes path name components suitable for appending to a webseed URL. This works for converting
 // S3 object keys to URLs too.
+//
 // Contrary to the name, this actually does a QueryEscape, rather than a
 // PathEscape. This works better with most S3 providers. You can use
-// EscapePathWithCustomEncoding for a custom encoding.
+// EscapePathWithOpts for a custom encoding.
 func EscapePath(pathComps []string) string {
 	return escapePath(pathComps, nil)
 }
 
-func escapePath(pathComps []string, encodeUrl func(string) string) string {
+func EscapePathWithCustomEscaper(pathComps []string, pathEscaper PathEscaper) string {
-	if encodeUrl == nil {
+	return escapePath(pathComps, pathEscaper)
-		encodeUrl = url.QueryEscape
-	}
-	return path.Join(
-		func() (ret []string) {
-			for _, comp := range pathComps {
-				ret = append(ret, encodeUrl(comp))
-			}
-			return
-		}()...,
-	)
 }
 
-func trailingPath(infoName string, fileComps []string, encodeUrl func(string) string) string {
+func escapePath(pathComps []string, pathEscaper PathEscaper) string {
-	return escapePath(append([]string{infoName}, fileComps...), encodeUrl)
+	if pathEscaper != nil {
+		return pathEscaper(pathComps)
+	}
+
+	var ret []string
+	for _, comp := range pathComps {
+		ret = append(ret, url.QueryEscape(comp))
+	}
+	return path.Join(ret...)
+}
+
+func trailingPath(
+	infoName string,
+	fileComps []string,
+	pathEscaper PathEscaper,
+) string {
+	return escapePath(append([]string{infoName}, fileComps...), pathEscaper)
 }
 
 // Creates a request per BEP 19.
-func NewRequest(url_ string, fileIndex int, info *metainfo.Info, offset, length int64) (*http.Request, error) {
+func NewRequest(
+	url_ string,
+	fileIndex int, info *metainfo.Info,
+	offset, length int64) (*http.Request, error) {
 	return newRequest(url_, fileIndex, info, offset, length, nil)
 }
 
-func NewRequestWithCustomUrlEncoding(
+func NewRequestWithOpts(
 	url_ string, fileIndex int,
 	info *metainfo.Info,
 	offset, length int64,
-	encodeUrl func(string) string,
+	pathEscaper PathEscaper,
 ) (*http.Request, error) {
-	return newRequest(url_, fileIndex, info, offset, length, encodeUrl)
+	return newRequest(url_, fileIndex, info, offset, length, pathEscaper)
 }
 
 func newRequest(
 	url_ string, fileIndex int,
 	info *metainfo.Info,
 	offset, length int64,
-	encodeUrl func(string) string,
+	pathEscaper PathEscaper,
 ) (*http.Request, error) {
 	fileInfo := info.UpvertedFiles()[fileIndex]
 	if strings.HasSuffix(url_, "/") {
 		// BEP specifies that we append the file path. We need to escape each component of the path
 		// for things like spaces and '#'.
-		url_ += trailingPath(info.Name, fileInfo.Path, encodeUrl)
+		url_ += escapePath(append([]string{info.Name}, fileInfo.Path...), pathEscaper)
 	}
 	req, err := http.NewRequest(http.MethodGet, url_, nil)
 	if err != nil {

webseed/request_test.go

@@ -2,28 +2,71 @@ package webseed
 
 import (
 	"net/url"
+	"path"
 	"testing"
 
 	qt "github.com/frankban/quicktest"
 )
 
-func TestTrailingPath(t *testing.T) {
+func TestEscapePath(t *testing.T) {
 	c := qt.New(t)
-	test := func(parts []string, result string) {
+	test := func(
-		unescaped, err := url.QueryUnescape(trailingPath(parts[0], parts[1:], url.QueryEscape))
+		parts []string, result string,
+		escaper PathEscaper,
+		unescaper func(string) (string, error),
+	) {
+		unescaped, err := unescaper(escapePath(parts, escaper))
 		if !c.Check(err, qt.IsNil) {
 			return
 		}
 		c.Check(unescaped, qt.Equals, result)
 	}
-	test([]string{"a_b-c", "d + e.f"}, "a_b-c/d + e.f")
+
-	test([]string{"a_1-b_c2", "d 3. (e, f).g"},
+	// Test with nil escapers (always uses url.QueryEscape)
+	// ------
+	test(
+		[]string{"a_b-c", "d + e.f"},
+		"a_b-c/d + e.f",
+		nil,
+		url.QueryUnescape,
+	)
+	test(
+		[]string{"a_1-b_c2", "d 3. (e, f).g"},
 		"a_1-b_c2/d 3. (e, f).g",
+		nil,
+		url.QueryUnescape,
+	)
+
+	// Test with custom escapers
+	// ------
+	test(
+		[]string{"a_b-c", "d + e.f"},
+		"a_b-c/d + e.f",
+		func(s []string) string {
+			var ret []string
+			for _, comp := range s {
+				ret = append(ret, url.PathEscape(comp))
+			}
+			return path.Join(ret...)
+		},
+		url.PathUnescape,
+	)
+	test(
+		[]string{"a_1-b_c2", "d 3. (e, f).g"},
+		"a_1-b_c2/d 3. (e, f).g",
+		func(s []string) string {
+			var ret []string
+			for _, comp := range s {
+				ret = append(ret, url.PathEscape(comp))
+			}
+			return path.Join(ret...)
+		},
+		url.PathUnescape,
 	)
 }
 
-func TestTrailingPathForEmptyInfoName(t *testing.T) {
+func TestEscapePathForEmptyInfoName(t *testing.T) {
-	qt.Check(t, trailingPath("", []string{`ノ┬─┬ノ ︵ ( \o°o)\`}, url.QueryEscape), qt.Equals, "%E3%83%8E%E2%94%AC%E2%94%80%E2%94%AC%E3%83%8E+%EF%B8%B5+%28+%5Co%C2%B0o%29%5C")
+	qt.Check(t, escapePath([]string{`ノ┬─┬ノ ︵ ( \o°o)\`}, nil), qt.Equals, "%E3%83%8E%E2%94%AC%E2%94%80%E2%94%AC%E3%83%8E+%EF%B8%B5+%28+%5Co%C2%B0o%29%5C")
-	qt.Check(t, trailingPath("", []string{"hello", "world"}, url.QueryEscape), qt.Equals, "hello/world")
+	qt.Check(t, escapePath([]string{"hello", "world"}, nil), qt.Equals, "hello/world")
-	qt.Check(t, trailingPath("war", []string{"and", "peace"}, url.QueryEscape), qt.Equals, "war/and/peace")
+	qt.Check(t, escapePath([]string{"war", "and", "peace"}, nil), qt.Equals, "war/and/peace")
 }