[#155] Fix error handling

Signed-off-by: Denis Kirillov <denis@nspcc.ru>

api/errors.go

@@ -1633,7 +1633,7 @@ func GetAPIError(code ErrorCode) Error {
 // getErrorResponse gets in standard error and resource value and
 // provides a encodable populated response values.
 func getAPIErrorResponse(ctx context.Context, err error, resource, requestID, hostID string) ErrorResponse {
-	code := "BadRequest"
+	code := "InternalError"
 	desc := err.Error()
 
 	info := GetReqInfo(ctx)

api/handler/list.go

@@ -2,7 +2,6 @@ package handler
 
 import (
 	"encoding/xml"
-	"errors"
 	"net/http"
 	"strconv"
 	"time"
@@ -120,18 +119,7 @@ func (h *handler) listObjects(w http.ResponseWriter, r *http.Request) (*listObje
 			zap.String("request_id", rid),
 			zap.Error(err))
 
-		var s3Err api.Error
+		api.WriteErrorResponse(r.Context(), w, err, r.URL)
-		if ok := errors.As(err, &s3Err); ok {
-			api.WriteErrorResponse(r.Context(), w, s3Err, r.URL)
-			return nil, nil, err
-		}
-
-		api.WriteErrorResponse(r.Context(), w, api.Error{
-			Code:           api.GetAPIError(api.ErrBadRequest).Code,
-			Description:    err.Error(),
-			HTTPStatusCode: http.StatusBadRequest,
-		}, r.URL)
-
 		return nil, nil, err
 	}
 

api/response.go

@@ -119,7 +119,7 @@ var s3ErrorResponseMap = map[string]string{
 
 // WriteErrorResponse writes error headers.
 func WriteErrorResponse(ctx context.Context, w http.ResponseWriter, err error, reqURL *url.URL) {
-	code := http.StatusBadRequest
+	code := http.StatusInternalServerError
 
 	if e, ok := err.(Error); ok {
 		code = e.HTTPStatusCode