Create root directory before saving avatar (#4515)

Fix avatar creation when no thumbnails have been created before. The
avatar is persisted in the same directory than thumbnails for Afero VFS,
and this directory needs to be created.

Author: nono

model/vfs/vfsafero/avatar.go

@@ -35,6 +35,9 @@ func (u *avatarUpload) Close() error {
 }
 
 func (a *avatarFS) CreateAvatar(contentType string) (io.WriteCloser, error) {
+	if err := a.fs.MkdirAll("/", 0755); err != nil {
+		return nil, err
+	}
 	f, err := afero.TempFile(a.fs, "/", AvatarFilename)
 	if err != nil {
 		return nil, err

web/settings/settings_test.go

@@ -1082,6 +1082,21 @@ func TestSettings(t *testing.T) {
 			Expect().Status(302).
 			Header("location").IsEqual(testInstance.DefaultRedirection().String())
 	})
+
+	t.Run("PutAvatar", func(t *testing.T) {
+		e := testutils.CreateTestClient(t, ts.URL)
+		sessCookie := session.CookieName(testInstance)
+
+		// Create a sample avatar image
+		avatarContent := "fake image content"
+
+		e.PUT("/settings/avatar").
+			WithCookie(sessCookie, "connected").
+			WithHeader("Authorization", "Bearer "+token).
+			WithHeader("Content-Type", "image/png").
+			WithBytes([]byte(avatarContent)).
+			Expect().Status(204)
+	})
 }
 
 func TestRegisterPassphraseForFlagshipApp(t *testing.T) {