add s3api error for copy in file, not directory

weed/s3api/s3api_object_handlers.go

@@ -436,10 +436,14 @@ func setEtag(w http.ResponseWriter, etag string) {
 }
 
 func filerErrorToS3Error(errString string) s3err.ErrorCode {
-	if strings.HasPrefix(errString, "existing ") && strings.HasSuffix(errString, "is a directory") {
+	switch {
+	case strings.HasPrefix(errString, "existing ") && strings.HasSuffix(errString, "is a directory"):
 		return s3err.ErrExistingObjectIsDirectory
+	case strings.HasSuffix(errString, "is a file"):
+		return s3err.ErrExistingObjectIsFile
+	default:
+		return s3err.ErrInternalError
 	}
-	return s3err.ErrInternalError
 }
 
 func (s3a *S3ApiServer) maybeAddFilerJwtAuthorization(r *http.Request, isWrite bool) {

weed/s3api/s3err/s3api_errors.go

@@ -101,6 +101,7 @@ const (
 	ErrPreconditionFailed
 
 	ErrExistingObjectIsDirectory
+	ErrExistingObjectIsFile
 )
 
 // error code to APIError structure, these fields carry respective
@@ -383,6 +384,11 @@ var errorCodeResponse = map[ErrorCode]APIError{
 		Description:    "Existing Object is a directory.",
 		HTTPStatusCode: http.StatusConflict,
 	},
+	ErrExistingObjectIsFile: {
+		Code:           "ExistingObjectIsFile",
+		Description:    "Existing Object is a file.",
+		HTTPStatusCode: http.StatusConflict,
+	},
 }
 
 // GetAPIError provides API Error for input API error code.