s3: add --s3-use-multipart-etag provider quirk #5993

Before this change the new multipart upload ETag checking code was
failing in the integration tests with Alibaba OSS.

Apparently Alibaba calculate the ETag in a different way to AWS.

This introduces a new provider quirk with a flag to disable the
checking of the ETag for multipart uploads.

Mulpart Etag checking has been enabled for all providers that we can
test for and work, and left disabled for the others.

backend/s3/s3.go

@@ -1548,6 +1548,14 @@ See: https://github.com/rclone/rclone/issues/4673, https://github.com/rclone/rcl
 This is usually set to a CloudFront CDN URL as AWS S3 offers
 cheaper egress for data downloaded through the CloudFront network.`,
 			Advanced: true,
+		}, {
+			Name: "use_multipart_etag",
+			Help: `Whether to use ETag in multipart uploads for verification
+
+This should be true, false or left unset to use the default for the provider.
+`,
+			Default:  fs.Tristate{},
+			Advanced: true,
 		},
 		}})
 }
@@ -1612,6 +1620,7 @@ type Options struct {
 	MemoryPoolUseMmap     bool                 `config:"memory_pool_use_mmap"`
 	DisableHTTP2          bool                 `config:"disable_http2"`
 	DownloadURL           string               `config:"download_url"`
+	UseMultipartEtag      fs.Tristate          `config:"use_multipart_etag"`
 }
 
 // Fs represents a remote s3 server
@@ -1915,12 +1924,13 @@ func setQuirks(opt *Options) {
 		listObjectsV2     = true
 		virtualHostStyle  = true
 		urlEncodeListings = true
+		useMultipartEtag  = true
 	)
 	switch opt.Provider {
 	case "AWS":
 		// No quirks
 	case "Alibaba":
-		// No quirks
+		useMultipartEtag = false // Alibaba seems to calculate multipart Etags differently from AWS
 	case "Ceph":
 		listObjectsV2 = false
 		virtualHostStyle = false
@@ -1933,13 +1943,16 @@ func setQuirks(opt *Options) {
 		listObjectsV2 = false // untested
 		virtualHostStyle = false
 		urlEncodeListings = false
+		useMultipartEtag = false // untested
 	case "Minio":
 		virtualHostStyle = false
 	case "Netease":
 		listObjectsV2 = false // untested
 		urlEncodeListings = false
+		useMultipartEtag = false // untested
 	case "RackCorp":
 		// No quirks
+		useMultipartEtag = false // untested
 	case "Scaleway":
 		// Scaleway can only have 1000 parts in an upload
 		if opt.MaxUploadParts > 1000 {
@@ -1950,6 +1963,7 @@ func setQuirks(opt *Options) {
 		listObjectsV2 = false // untested
 		virtualHostStyle = false
 		urlEncodeListings = false
+		useMultipartEtag = false // untested
 	case "StackPath":
 		listObjectsV2 = false // untested
 		virtualHostStyle = false
@@ -1960,18 +1974,21 @@ func setQuirks(opt *Options) {
 			opt.ChunkSize = 64 * fs.Mebi
 		}
 	case "TencentCOS":
-		listObjectsV2 = false // untested
+		listObjectsV2 = false    // untested
+		useMultipartEtag = false // untested
 	case "Wasabi":
 		// No quirks
 	case "Other":
 		listObjectsV2 = false
 		virtualHostStyle = false
 		urlEncodeListings = false
+		useMultipartEtag = false
 	default:
 		fs.Logf("s3", "s3 provider %q not known - please set correctly", opt.Provider)
 		listObjectsV2 = false
 		virtualHostStyle = false
 		urlEncodeListings = false
+		useMultipartEtag = false
 	}
 
 	// Path Style vs Virtual Host style
@@ -1993,6 +2010,12 @@ func setQuirks(opt *Options) {
 			opt.ListVersion = 1
 		}
 	}
+
+	// Set the correct use multipart Etag for error checking if not manually set
+	if !opt.UseMultipartEtag.Valid {
+		opt.UseMultipartEtag.Valid = true
+		opt.UseMultipartEtag.Value = useMultipartEtag
+	}
 }
 
 // setRoot changes the root of the Fs
@@ -3864,7 +3887,7 @@ func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, op
 		return err
 	}
 	o.setMetaData(head.ETag, head.ContentLength, head.LastModified, head.Metadata, head.ContentType, head.StorageClass)
-	if !o.fs.etagIsNotMD5 && wantETag != "" && head.ETag != nil && *head.ETag != "" {
+	if o.fs.opt.UseMultipartEtag.Value && !o.fs.etagIsNotMD5 && wantETag != "" && head.ETag != nil && *head.ETag != "" {
 		gotETag := strings.Trim(strings.ToLower(*head.ETag), `"`)
 		if wantETag != gotETag {
 			return fmt.Errorf("multipart upload corrupted: Etag differ: expecting %s but got %s", wantETag, gotETag)