Re: [RFC/PATCH 2/4] Restructuring git-merge.sh

[Junio C Hamano <gitster@pobox.com>]

"Sverre Hvammen Johansen" <hvammen@gmail.com> writes:

> for preparation of new feature:

Full sentence, please?

>
>    Head reduction before selecting merge strategy
>
> Signed-off-by: Sverre Hvammen Johansen <hvammen@gmail.com>
> ---
>  git-merge.sh |  166 ++++++++++++++++++++++++++++++----------------------------
>  1 files changed, 85 insertions(+), 81 deletions(-)
>
> diff --git a/git-merge.sh b/git-merge.sh
> index 17f40f2..2acd2cc 100755
> --- a/git-merge.sh
> +++ b/git-merge.sh
> @@ -207,6 +207,29 @@ parse_config () {
>         args_left=$#
>  }
>
> +# Find real parents
> +# Set the following variables as followd:
> +#   real_parents: The parents specified on the command line
> +#   common:       All common ancestors or not_queried
> +#   ff_head:      Fast forward of head

"Fast forward of head"?  Puzzled, and sorry I cannot offer a better
rewrite for this one as I do not quite get what you are trying to say
here.

> +find_real_parents () {
> +       real_parents=$(git rev-parse "$@")
> +       real_parents=${real_parents#$LF}

What is this "#$LF" for?  rev-parse begins its output with an empty line
and you want to strip it?

> +       if test $# = 1
> +       then
> +               common=$(git merge-base --all $head "$@")
> +               if test "$common" = $head
> +               then
> +                       ff_head=$1
> +               else
> +                       ff_head=$head
> +               fi

So for a single-remote merge, merge-base is run and common is set.

> @@ -339,87 +364,66 @@ do
> +if true
> +then

This caught my attention before looking at 3/4 ;-).

> -       # An octopus.  If we can reach all the remote we are up to date.
> -       up_to_date=t
> -       for remote
> -       do
> -               common_one=$(git merge-base --all $head $remote)
> -               if test "$common_one" != "$remote"
>                 then
> -                       up_to_date=f
> -                       break
>                 fi
> -       done
> -       if test "$up_to_date" = t
> -       then
> -               finish_up_to_date "Already up-to-date. Yeeah!"
>                 exit 0
>         fi

This optimization seems to have been lost, even though it was supposed to
be just code restructuring.

> +fi
> +
> +case "$real_parents" in
> +?*"$LF"?*)
> +       # We have more than one parent
> +       common=$(git show-branch --merge-base $head $real_parents)
>         ;;
> +*)
> +       # We have exactly one parent
> +       test "$common" != not_queried || common=$(git merge-base --all
> $head $real_parents)

How can "not_queried" be possible here?