Incorrect message displayed when editing memberships without sending emails

When editing a membership, even if the checkbox "Send Confirmation and Receipt?" is not checked, a message is displayed after Save is pressed which always includes the text "A confirmation and receipt has been sent to email@example.com." Note that the email is not sent in this case (as expected). The expectation is that this text is not displayed if an email is not sent. This was reproduced on d46.demo.civicrm.org.