webdav: add support for parsing more time formats

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/webdavd/file.go

@@ -443,7 +443,7 @@ func (f *webDavFile) Patch(patches []webdav.Proppatch) ([]webdav.Propstat, error
 		for _, p := range patch.Props {
 			if status == http.StatusForbidden && !hasError {
 				if !patch.Remove && util.Contains(lastModifiedProps, p.XMLName.Local) {
-					parsed, err := http.ParseTime(string(p.InnerXML))
+					parsed, err := parseTime(string(p.InnerXML))
 					if err != nil {
 						f.Connection.Log(logger.LevelWarn, "unsupported last modification time: %q, err: %v",
 							string(p.InnerXML), err)

internal/webdavd/internal_test.go

@@ -1611,6 +1611,15 @@ func TestMisc(t *testing.T) {
 	certMgr = oldCertMgr
 }
 
+func TestParseTime(t *testing.T) {
+	res, err := parseTime("Sat, 4 Feb 2023 17:00:50 GMT")
+	require.NoError(t, err)
+	require.Equal(t, int64(1675530050), res.Unix())
+	res, err = parseTime("Wed, 04 Nov 2020 13:25:51 GMT")
+	require.NoError(t, err)
+	require.Equal(t, int64(1604496351), res.Unix())
+}
+
 func TestConfigsFromProvider(t *testing.T) {
 	configDir := "."
 	err := dataprovider.UpdateConfigs(nil, "", "", "")

internal/webdavd/webdavd.go

@@ -18,8 +18,10 @@ package webdavd
 import (
 	"fmt"
 	"net"
+	"net/http"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/go-chi/chi/v5/middleware"
 
@@ -43,6 +45,12 @@ const (
 var (
 	certMgr       *common.CertManager
 	serviceStatus ServiceStatus
+	timeFormats   = []string{
+		http.TimeFormat,
+		"Mon, _2 Jan 2006 15:04:05 GMT",
+		time.RFC850,
+		time.ANSIC,
+	}
 )
 
 // ServiceStatus defines the service status
@@ -352,3 +360,13 @@ func getConfigPath(name, configDir string) string {
 	}
 	return name
 }
+
+func parseTime(text string) (t time.Time, err error) {
+	for _, layout := range timeFormats {
+		t, err = time.Parse(layout, text)
+		if err == nil {
+			return
+		}
+	}
+	return
+}