Hi Johannes,
Johannes Schindelin <johannes.schindelin@xxxxxx> writes:
> The first step of an interactive rebase is to generate the so-called "todo
> script", to be stored in the state directory as "git-rebase-todo" and to
> be edited by the user.
>
> Originally, we adjusted the output of `git log <options>` using a simple
> sed script. Over the course of the years, the code became more
> complicated. We now use shell scripting to edit the output of `git log`
> conditionally, depending whether to keep "empty" commits (i.e. commits
> that do not change any files).
>
> On platforms where shell scripting is not native, this can be a serious
> drag. And it opens the door for incompatibilities between platforms when
> it comes to shell scripting or to Unix-y commands.
>
> Let's just re-implement the todo script generation in plain C, using the
> revision machinery directly.
>
> This is substantially faster, improving the speed relative to the
> shell script version of the interactive rebase from 2x to 3x on Windows.
>
> Note that the rearrange_squash() function in git-rebase--interactive
> relied on the fact that we set the "format" variable to the config setting
> rebase.instructionFormat. Relying on a side effect like this is no good,
> hence we explicitly perform that assignment (possibly again) in
> rearrange_squash().
>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@xxxxxx>
> ---
> builtin/rebase--helper.c | 8 +++++++-
> git-rebase--interactive.sh | 44 +++++++++++++++++++++--------------------
> sequencer.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++
> sequencer.h | 3 +++
> 4 files changed, 82 insertions(+), 22 deletions(-)
>
> diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c
> index ca1ebb2fa18..821058d452d 100644
> --- a/builtin/rebase--helper.c
> +++ b/builtin/rebase--helper.c
> @@ -11,15 +11,19 @@ static const char * const builtin_rebase_helper_usage[] = {
> int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
> {
> struct replay_opts opts = REPLAY_OPTS_INIT;
> + int keep_empty = 0;
> enum {
> - CONTINUE = 1, ABORT
> + CONTINUE = 1, ABORT, MAKE_SCRIPT
> } command = 0;
> struct option options[] = {
> OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
> + OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
> OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
> CONTINUE),
> OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
> ABORT),
> + OPT_CMDMODE(0, "make-script", &command,
> + N_("make rebase script"), MAKE_SCRIPT),
> OPT_END()
> };
>
> @@ -36,5 +40,7 @@ int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
> return !!sequencer_continue(&opts);
> if (command == ABORT && argc == 1)
> return !!sequencer_remove_state(&opts);
> + if (command == MAKE_SCRIPT && argc > 1)
> + return !!sequencer_make_script(keep_empty, stdout, argc, argv);
> usage_with_options(builtin_rebase_helper_usage, options);
> }
> diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
> index 2c9c0165b5a..609e150d38f 100644
> --- a/git-rebase--interactive.sh
> +++ b/git-rebase--interactive.sh
> @@ -785,6 +785,7 @@ collapse_todo_ids() {
> # each log message will be re-retrieved in order to normalize the
> # autosquash arrangement
> rearrange_squash () {
> + format=$(git config --get rebase.instructionFormat)
> # extract fixup!/squash! lines and resolve any referenced sha1's
> while read -r pick sha1 message
> do
> @@ -1210,26 +1211,27 @@ else
> revisions=$onto...$orig_head
> shortrevisions=$shorthead
> fi
> -format=$(git config --get rebase.instructionFormat)
> -# the 'rev-list .. | sed' requires %m to parse; the instruction requires %H to parse
> -git rev-list $merges_option --format="%m%H ${format:-%s}" \
> - --reverse --left-right --topo-order \
> - $revisions ${restrict_revision+^$restrict_revision} | \
> - sed -n "s/^>//p" |
> -while read -r sha1 rest
> -do
> -
> - if test -z "$keep_empty" && is_empty_commit $sha1 && ! is_merge_commit $sha1
> - then
> - comment_out="$comment_char "
> - else
> - comment_out=
> - fi
> +if test t != "$preserve_merges"
> +then
> + git rebase--helper --make-script ${keep_empty:+--keep-empty} \
> + $revisions ${restrict_revision+^$restrict_revision} >"$todo"
> +else
> + format=$(git config --get rebase.instructionFormat)
> + # the 'rev-list .. | sed' requires %m to parse; the instruction requires %H to parse
> + git rev-list $merges_option --format="%m%H ${format:-%s}" \
> + --reverse --left-right --topo-order \
> + $revisions ${restrict_revision+^$restrict_revision} | \
> + sed -n "s/^>//p" |
> + while read -r sha1 rest
> + do
> +
> + if test -z "$keep_empty" && is_empty_commit $sha1 && ! is_merge_commit $sha1
> + then
> + comment_out="$comment_char "
> + else
> + comment_out=
> + fi
>
> - if test t != "$preserve_merges"
> - then
> - printf '%s\n' "${comment_out}pick $sha1 $rest" >>"$todo"
> - else
> if test -z "$rebase_root"
> then
> preserve=t
> @@ -1248,8 +1250,8 @@ do
> touch "$rewritten"/$sha1
> printf '%s\n' "${comment_out}pick $sha1 $rest" >>"$todo"
> fi
> - fi
> -done
> + done
> +fi
>
> # Watch for commits that been dropped by --cherry-pick
> if test t = "$preserve_merges"
> diff --git a/sequencer.c b/sequencer.c
> index 130cc868e51..88819a1a2a9 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -2388,3 +2388,52 @@ void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag)
>
> strbuf_release(&sob);
> }
> +
> +int sequencer_make_script(int keep_empty, FILE *out,
> + int argc, const char **argv)
> +{
> + char *format = NULL;
> + struct pretty_print_context pp = {0};
> + struct strbuf buf = STRBUF_INIT;
> + struct rev_info revs;
> + struct commit *commit;
> +
> + init_revisions(&revs, NULL);
> + revs.verbose_header = 1;
> + revs.max_parents = 1;
> + revs.cherry_pick = 1;
> + revs.limited = 1;
> + revs.reverse = 1;
> + revs.right_only = 1;
> + revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
> + revs.topo_order = 1;
> +
> + revs.pretty_given = 1;
> + git_config_get_string("rebase.instructionFormat", &format);
> + if (!format || !*format) {
> + free(format);
> + format = xstrdup("%s");
> + }
> + get_commit_format(format, &revs);
> + free(format);
> + pp.fmt = revs.commit_format;
> + pp.output_encoding = get_log_output_encoding();
> +
> + if (setup_revisions(argc, argv, &revs, NULL) > 1)
> + return error(_("make_script: unhandled options"));
> +
> + if (prepare_revision_walk(&revs) < 0)
> + return error(_("make_script: error preparing revisions"));
> +
> + while ((commit = get_revision(&revs))) {
> + strbuf_reset(&buf);
> + if (!keep_empty && is_original_commit_empty(commit))
> + strbuf_addf(&buf, "%c ", comment_line_char);
I've never had to use empty commits before, but while testing this, I
noticed that `git rebase -i --keep-empty` behaves differently if using
the --root option instead of a branch or something like 'HEAD~10'.
I also tested this on v2.13.0 and the behavior is the same.
> + strbuf_addf(&buf, "pick %s ", oid_to_hex(&commit->object.oid));
> + pretty_print_commit(&pp, commit, &buf);
> + strbuf_addch(&buf, '\n');
> + fputs(buf.buf, out);
> + }
> + strbuf_release(&buf);
> + return 0;
> +}
> diff --git a/sequencer.h b/sequencer.h
> index f885b68395f..83f2943b7a9 100644
> --- a/sequencer.h
> +++ b/sequencer.h
> @@ -45,6 +45,9 @@ int sequencer_continue(struct replay_opts *opts);
> int sequencer_rollback(struct replay_opts *opts);
> int sequencer_remove_state(struct replay_opts *opts);
>
> +int sequencer_make_script(int keep_empty, FILE *out,
> + int argc, const char **argv);
> +
> extern const char sign_off_header[];
>
> void append_signoff(struct strbuf *msgbuf, int ignore_footer, unsigned flag);
> --
> 2.12.2.windows.2.800.gede8f145e06
Liam