b2: fix decoding of 404 errors producing "Couldn't decode error response: EOF"

See: https://forum.rclone.org/t/move-to-b2-creates-empty-file-versions/23420/

backend/b2/b2.go

@@ -9,6 +9,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha1"
+	"encoding/json"
 	"fmt"
 	gohash "hash"
 	"io"
@@ -344,11 +345,17 @@ func (f *Fs) shouldRetry(ctx context.Context, resp *http.Response, err error) (b
 
 // errorHandler parses a non 2xx error response into an error
 func errorHandler(resp *http.Response) error {
+	body, err := rest.ReadBody(resp)
+	if err != nil {
+		return errors.Wrap(err, "error reading error out of body")
+	}
 	// Decode error response
 	errResponse := new(api.Error)
-	err := rest.DecodeJSON(resp, &errResponse)
-	if err != nil {
-		fs.Debugf(nil, "Couldn't decode error response: %v", err)
+	if len(body) > 0 {
+		err := json.Unmarshal(body, &errResponse)
+		if err != nil {
+			fs.Debugf(nil, "Couldn't decode error response: %v", err)
+		}
 	}
 	if errResponse.Code == "" {
 		errResponse.Code = "unknown"
@@ -357,7 +364,7 @@ func errorHandler(resp *http.Response) error {
 		errResponse.Status = resp.StatusCode
 	}
 	if errResponse.Message == "" {
-		errResponse.Message = "Unknown " + resp.Status
+		errResponse.Message = fmt.Sprintf("Unknown: %s: %s", resp.Status, body)
 	}
 	return errResponse
 }

backend/ftp/ftp.go

@@ -241,23 +241,6 @@ func (dl *debugLog) Write(p []byte) (n int, err error) {
 	return len(p), nil
 }
 
-type dialCtx struct {
-	f   *Fs
-	ctx context.Context
-}
-
-// dial a new connection with fshttp dialer
-func (d *dialCtx) dial(network, address string) (net.Conn, error) {
-	conn, err := fshttp.NewDialer(d.ctx).Dial(network, address)
-	if err != nil {
-		return nil, err
-	}
-	if d.f.tlsConf != nil {
-		conn = tls.Client(conn, d.f.tlsConf)
-	}
-	return conn, err
-}
-
 // shouldRetry returns a boolean as to whether this err deserve to be
 // retried.  It returns the err as a convenience
 func shouldRetry(ctx context.Context, err error) (bool, error) {
@@ -277,9 +260,22 @@ func shouldRetry(ctx context.Context, err error) (bool, error) {
 // Open a new connection to the FTP server.
 func (f *Fs) ftpConnection(ctx context.Context) (c *ftp.ServerConn, err error) {
 	fs.Debugf(f, "Connecting to FTP server")
-	dCtx := dialCtx{f, ctx}
-	ftpConfig := []ftp.DialOption{ftp.DialWithDialFunc(dCtx.dial)}
-	if f.opt.ExplicitTLS {
+
+	// Make ftp library dial with fshttp dialer optionally using TLS
+	dial := func(network, address string) (conn net.Conn, err error) {
+		conn, err = fshttp.NewDialer(ctx).Dial(network, address)
+		if f.tlsConf != nil && err == nil {
+			conn = tls.Client(conn, f.tlsConf)
+		}
+		return
+	}
+	ftpConfig := []ftp.DialOption{ftp.DialWithDialFunc(dial)}
+
+	if f.opt.TLS {
+		// Our dialer takes care of TLS but ftp library also needs tlsConf
+		// as a trigger for sending PSBZ and PROT options to server.
+		ftpConfig = append(ftpConfig, ftp.DialWithTLS(f.tlsConf))
+	} else if f.opt.ExplicitTLS {
 		ftpConfig = append(ftpConfig, ftp.DialWithExplicitTLS(f.tlsConf))
 		// Initial connection needs to be cleartext for explicit TLS
 		conn, err := fshttp.NewDialer(ctx).Dial("tcp", f.dialAddr)

backend/webdav/odrvcookie/fetch.go

@@ -125,7 +125,7 @@ func (ca *CookieAuth) getSPCookie(conf *SharepointSuccessResponse) (*CookieRespo
 		return nil, errors.Wrap(err, "Error while constructing endpoint URL")
 	}
 
-	u, err := url.Parse("https://" + spRoot.Host + "/_forms/default.aspx?wa=wsignin1.0")
+	u, err := url.Parse(spRoot.Scheme + "://" + spRoot.Host + "/_forms/default.aspx?wa=wsignin1.0")
 	if err != nil {
 		return nil, errors.Wrap(err, "Error while constructing login URL")
 	}