[PATCH 0/5] bisect: Add support for a --no-checkout option.

For some bisection tasks, checking out the commit at each stage of the bisection process is unecessary or undesirable.

This series adds support for a --no-checkout[=<ref>] option to git-bisect.

If specified, this option causes git-bisect to update the specified reference at each stage of the bisection process instead of checking out the commit at that point. If <ref> is not specified, HEAD is assumed.

One application of this option is to find, within a partially damaged repository, the earliest commit such that the graph of commits, trees and blobs reachable from the parents of that commit is completely reachable. 

For example:

    git bisect start HEAD <known-good-commit> [ <damaged-or-missing-commit> ... ]
    git bisect run eval '
    	git rev-list --objects HEAD > /dev/null && 
	git rev-list --objects HEAD | git pack-objects --stdout >/dev/null || 
	false'

Assuming this git bisect run completes successfully, bisect/bad will refer to the first commit whose parents have completely reachable graphs.

This series is a reworking of an earlier series "bisect: allow git bisect to be used with repos containing damaged trees." that incorporates Junio's suggestion to add a --no-checkout option instead of an --ignore-checkout-failure option.

Jon Seymour (5):
  bisect: add tests to document expected behaviour in presence of
    broken trees.
  bisect: introduce support for --no-checkout=<ref> option.
  bisect: introduce --no-checkout[=<ref>] support into porcelain.
  bisect: add tests for the --no-checkout option.
  bisect: add documentation for --no-checkout[=<ref>] option.

 Documentation/git-bisect.txt |   26 ++++++++-
 bisect.c                     |   26 +++++++-
 bisect.h                     |    2 +-
 builtin/bisect--helper.c     |    7 ++-
 git-bisect.sh                |   45 ++++++++++++--
 t/t6030-bisect-porcelain.sh  |  132 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 223 insertions(+), 15 deletions(-)