Re: [TopGit TOY PATCH] tg-graft: forge tip--base--<deps...> history for a subcommand

> Adds a command 'tg graft <command>' that evaluates <command> with a
> special GIT_GRAFT_FILE: the parent of each patch head is its patch
> base, and the parents of the patch base are the dependencies of the
> patch.
>
> Try, for example, 'tg graft "gitk --all"'.
>
> Signed-off-by: Thomas Rast <trast@student.ethz.ch>
> ---
>
> Mainly sending this so someone can turn it into a useful feature, and
> maybe build a few subcommands on top of it (that might call gitk or
> 'git log --graph', for example).
>
> The one big issue with the resulting history is that the commit
> messages at the tip aren't very interesting and may even be completely
> irrelevant (for a base merge).  I don't see a good solution for that.
>
>  Makefile    |    2 +-
>  tg-graft.sh |   47 +++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 48 insertions(+), 1 deletions(-)
>  create mode 100755 tg-graft.sh
>
> diff --git a/Makefile b/Makefile
> index 6eade1e..57745c0 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -6,7 +6,7 @@ sharedir = $(PREFIX)/share/topgit
>  hooksdir = $(cmddir)/hooks
>
>
> -commands_in = tg-create.sh tg-delete.sh tg-export.sh tg-info.sh tg-patch.sh tg-summary.sh tg-update.sh
> +commands_in = tg-create.sh tg-delete.sh tg-export.sh tg-info.sh tg-patch.sh tg-summary.sh tg-update.sh tg-graft.sh

>  hooks_in = hooks/pre-commit.sh
>
>  commands_out = $(patsubst %.sh,%,$(commands_in))
> diff --git a/tg-graft.sh b/tg-graft.sh
> new file mode 100755
> index 0000000..b6d0458
> --- /dev/null
> +++ b/tg-graft.sh
> @@ -0,0 +1,47 @@
> +#!/bin/sh
> +# TopGit - A different patch queue manager
> +# (c) Petr Baudis <pasky@suse.cz>  2008
> +# GPLv2
> +
> +if [ -z "$1" -o -n "$2" ]; then
> +       echo "Usage: tg graft <command>" >&2
> +       exit 1
> +fi
> +
> +mkdir -p "$git_dir"/info