Mike Edgar <adgar@google.com> [Wed, 06 Aug 2014 16:51:41 -0400] rev 22152
histedit: add "roll" command to fold commit data and drop message (issue4256)
This new histedit command (short for "rollup") is a variant of "fold" akin to
"hg amend" for working copy: it accumulates changes without interrupting
the user and asking for an updated commit message.