junos config commit question

["Lyndon Nerenberg (VE7TFX/VE6BBM)" <lyndon () orthanc ca>]

On an EX4300 switch running JunOS 14.1 let's imagine I typed

        config
        delete interfaces

before coming to my senses.  How am I supposed to back out of that
mess?  For the life of me, after a week of reading the 3000 page
reference manual, and endless DuckDuckGoing, I cannot see a simple
way of just abandoning the commit.  I've got to be missing something
stunningly obvious here because it's unthinkable that this functionality
doesn't exist.  Help?!?

The only way out I can see is to drop into the shell, make an
uncompressed copy of juniper.conf.gz, then pop back into the config
editor and load that over top of the editor's config view.  Surely
there's a saner way of dealing with this.

--lyndon