Unable to upload empty files to seaweed via. multipart when length is unknown (#6729)

weed/s3api/filer_multipart.go

@@ -84,11 +84,15 @@ func (s3a *S3ApiServer) completeMultipartUpload(input *s3.CompleteMultipartUploa
 	}
 	completedPartNumbers := []int{}
 	completedPartMap := make(map[int][]string)
+
+	maxPartNo := 1
+
 	for _, part := range parts.Parts {
 		if _, ok := completedPartMap[part.PartNumber]; !ok {
 			completedPartNumbers = append(completedPartNumbers, part.PartNumber)
 		}
 		completedPartMap[part.PartNumber] = append(completedPartMap[part.PartNumber], part.ETag)
+		maxPartNo = max(maxPartNo, part.PartNumber)
 	}
 	sort.Ints(completedPartNumbers)
 
@@ -156,7 +160,7 @@ func (s3a *S3ApiServer) completeMultipartUpload(input *s3.CompleteMultipartUploa
 				glog.Warningf("invalid complete etag %s, partEtag %s", partETag, entryETag)
 				stats.S3HandlerCounter.WithLabelValues(stats.ErrorCompletedEtagInvalid).Inc()
 			}
-			if len(entry.Chunks) == 0 {
+			if len(entry.Chunks) == 0 && partNumber != maxPartNo {
 				glog.Warningf("completeMultipartUpload %s empty chunks", entry.Name)
 				stats.S3HandlerCounter.WithLabelValues(stats.ErrorCompletedPartEmpty).Inc()
 				continue