Merge branch 'al/bisect-first-parent'

"git bisect" learns the "--first-parent" option to find the first
breakage along the first-parent chain.

* al/bisect-first-parent:
  bisect: combine args passed to find_bisection()
  bisect: introduce first-parent flag
  cmd_bisect__helper: defer parsing no-checkout flag
  rev-list: allow bisect and first-parent flags
  t6030: modernize "git bisect run" tests

diff --cc bisect.c
index a088a0f82eec47247fc1eb938afcb6636d071ff2,1585fcc6ad068b948836003afb60c5009b500f25..d42a3a3767d60bd36af1d57aabd8adc1be5fd378
--- 1/bisect.c
--- 2/bisect.c
+++ b/bisect.c
@@@ -454,9 -461,10 +461,10 @@@ static GIT_PATH_FUNC(git_path_bisect_ru
  static GIT_PATH_FUNC(git_path_bisect_start, "BISECT_START")
  static GIT_PATH_FUNC(git_path_bisect_log, "BISECT_LOG")
  static GIT_PATH_FUNC(git_path_bisect_terms, "BISECT_TERMS")
+ static GIT_PATH_FUNC(git_path_bisect_first_parent, "BISECT_FIRST_PARENT")
  static GIT_PATH_FUNC(git_path_head_name, "head-name")
  
 -static void read_bisect_paths(struct argv_array *array)
 +static void read_bisect_paths(struct strvec *array)
  {
        struct strbuf str = STRBUF_INIT;
        const char *filename = git_path_bisect_names();

diff --cc builtin/bisect--helper.c
Simple merge

diff --cc git-bisect.sh
Simple merge

diff --cc revision.c
Simple merge

diff --cc t/t6000-rev-list-misc.sh
Simple merge