.\" svn-bisect.1
.\" Copyright 2009 by Peter Samuelson
.\" Permission is granted to everyone to use and distribute this work,
.\" without limitation, modified or unmodified, in any way, for any purpose.
.TH SVN-BISECT 1 "2009-10-22"
.\"
.SH NAME
svn\-bisect \- Bisect Subversion revisions to find a regression
.\"
.SH SYNOPSIS
.B svn\-bisect start
.RI [ good_rev " [" bad_rev ]]
.PP
.BR svn\-bisect " {" good | bad "} "
.RI [ rev ]
.PP
.B svn\-bisect run
.I command
.PP
.B svn\-bisect reset
.PP
.B svn\-bisect status
.\"
.SH DESCRIPTION
.B svn\-bisect
helps to automate finding a bug or behavior change in a
.B Subversion
working copy.  Given an initial \(lqgood\(rq revision, with the desired
or original behavior, and a newer \(lqbad\(rq revision, with the
undesired or modified behavior,
.B svn\-bisect
will do a binary search through the revision range to find which
revision caused the change.
.PP
.B svn\-bisect
must be initialized in a working copy, with
.BR "svn\-bisect start" .
It also needs to be given at least one
.IR good
revision (the baseline) and one
.I bad
revision (known modified behavior) revision.
.PP
Sub-commands:
.TP
.B start
Initializes or reinitializes
.BR svn\-bisect ;
optionally takes
.IR good " and " bad
revision parameters.
.TP
.BI good " rev"
.TP
.BI bad " rev"
Tells
.B svn\-bisect
that a revision is
.IR good " or " bad ,
defining or narrowing the search space.  If not specified,
.I revision
defaults to the current revision in the working copy.
.B svn\-bisect
will then update to a revision halfway between the new
.IR good " and " bad
boundaries.  If this update crosses a point where a branch was created,
it switches in or out of the branch.
.TP
.B reset
Resets the working copy to the revision and branch where
.B svn\-bisect start
was run.  In the simple case this is equivalent to
.BR "rm -r .svn-bisect; svn update" ,
but not if it has crossed branches, and not if you did not start at the
.B HEAD
revision.  In any case,
.B svn\-bisect
never keeps track of mixed-revision working copies, so do not use
.B svn\-bisect
in a working copy that will need to be restored to mixed revisions.
.TP
.B status
Prints a brief status message.
.TP
.BI run " command"
Runs the bisection in a loop.  You must have already defined initial
.IR good " and " bad
boundary conditions.  Each iteration through the loop runs
.I command
as a shell command (a single argument, quoted if necessary) on the
chosen revision, then marks the revision as
.IR good " or " bad ,
based on the exit status of
.IR command .
.\"
.SH EXAMPLES
Assume you are trying to find which revision between 1250 and 1400
caused the
.B make check
command to fail.
.PP
    svn\-bisect start 1250 1400
    svn\-bisect run \(aqmake check\(aq
    svn\-bisect reset
.\"
.SH ENVIRONMENT
.IP SVN
The Subversion command-line program to call (default
.BR svn ).
.SH FILES
.IP \.svn\-bisect
The directory containing state information, removed after a successful
bisection.
.\"
.SH "SEE ALSO"
.BR git\-bisect (1).
.\"
.SH AUTHOR
.\" <rmh@aybabtu.com>, <peter@p12n.org>
Written by Robert Millan and Peter Samuelson, for the Debian Project
(but may be used by others).