"site error" when operating at manage_catalogIndexes with no index selected

[jugmac00]

• fresh zope installation
• create catalog
• create index
• hit "Remove index", "Reindex" or "Clear index" without selecting any index

=> site error

traceback

2019-11-07 19:22:42 ERROR [Zope.SiteErrorLog:251][waitress] 1573150962.83299850.1552368168387197 http://localhost:8080/some_catalog/manage_delIndex
Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 151, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 333, in publish_module
  Module ZPublisher.WSGIPublisher, line 251, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 57, in call_object
  Module Products.ZCatalog.ZCatalog, line 380, in manage_delIndex
zExceptions.BadRequest: No items specified
2019-11-07 19:22:46 ERROR [Zope.SiteErrorLog:251][waitress] 1573150966.34321830.784474428972252 http://localhost:8080/some_catalog/manage_reindexIndex
Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 151, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 333, in publish_module
  Module ZPublisher.WSGIPublisher, line 251, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 57, in call_object
  Module Products.ZCatalog.ZCatalog, line 447, in manage_reindexIndex
zExceptions.BadRequest: No items specified
2019-11-07 19:22:49 ERROR [Zope.SiteErrorLog:251][waitress] 1573150969.04492260.37519484376976475 http://localhost:8080/some_catalog/manage_clearIndex
Traceback (innermost last):
  Module ZPublisher.WSGIPublisher, line 151, in transaction_pubevents
  Module ZPublisher.WSGIPublisher, line 333, in publish_module
  Module ZPublisher.WSGIPublisher, line 251, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZPublisher.WSGIPublisher, line 57, in call_object
  Module Products.ZCatalog.ZCatalog, line 398, in manage_clearIndex
zExceptions.BadRequest: No items specified

A friendly error message would be nice.