Re: [PATCH 2/2] rebase -r: fix the total number shown in the progress

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
> 
> For regular, non-`--rebase-merges` runs, there is very little work to do
> for the parser when determining the total number of commands in a rebase
> script: it is simply the number of lines after stripping the commented
> lines and then trimming the trailing empty line, if any.
> 
> The `--rebase-merges` mode complicates things by introducing empty lines
> and comments in the middle of the script. These should _not_ be counted
> as commands, and indeed, when an interactive rebase is interrupted and
> subsequently resumed, the total number of commands can magically shrink,
> sometimes dramatically.
> 
> The reason for this strange behavior is that empty lines _are_ counted
> in `edit_todo_list()` (but not the comments, as they are stripped via
> `strbuf_stripspace(..., 1)`, which is a bug.
> 
> Let's fix this so that the correct total number is shown from the
> get-go, by carefully adjusting it according to what's in the rebase
> script. Extra care needs to be taken in case the user edits the script:
> the number of commands might be different after the user edited than
> beforehand.
> 
> Note: Even though commented lines are skipped in `edit_todo_list()`, we
> still need to handle `TODO_COMMENT` items by decrementing the
> already-incremented `total_nr` again: empty lines are also marked as
> `TODO_COMMENT`.
> 
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>   sequencer.c              | 12 ++++++++----
>   t/t3430-rebase-merges.sh |  7 +++++++
>   2 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/sequencer.c b/sequencer.c
> index f5d89abdc5e..46dd07df0f2 100644
> --- a/sequencer.c
> +++ b/sequencer.c
> @@ -2609,7 +2609,7 @@ int todo_list_parse_insn_buffer(struct repository *r, char *buf,
>   	char *p = buf, *next_p;
>   	int i, res = 0, fixup_okay = file_exists(rebase_path_done());
>   
> -	todo_list->current = todo_list->nr = 0;
> +	todo_list->current = todo_list->nr = todo_list->total_nr = 0;
>   
>   	for (i = 1; *p; i++, p = next_p) {
>   		char *eol = strchrnul(p, '\n');
> @@ -2628,7 +2628,8 @@ int todo_list_parse_insn_buffer(struct repository *r, char *buf,
>   			item->arg_offset = p - buf;
>   			item->arg_len = (int)(eol - p);
>   			item->commit = NULL;
> -		}
> +		} else if (item->command == TODO_COMMENT)
> +			todo_list->total_nr--;

>   
>   		if (fixup_okay)
>   			; /* do nothing */
> @@ -6039,7 +6040,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
>   	struct todo_list new_todo = TODO_LIST_INIT;
>   	struct strbuf *buf = &todo_list->buf, buf2 = STRBUF_INIT;
>   	struct object_id oid = onto->object.oid;
> -	int res;
> +	int new_total_nr, res;
>   
>   	find_unique_abbrev_r(shortonto, &oid, DEFAULT_ABBREV);
>   
> @@ -6066,6 +6067,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
>   		return error(_("nothing to do"));
>   	}
>   
> +	new_total_nr = todo_list->total_nr - count_commands(todo_list);
>   	res = edit_todo_list(r, todo_list, &new_todo, shortrevisions,
>   			     shortonto, flags);
>   	if (res == -1)
> @@ -6088,11 +6090,13 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
>   		return -1;
>   	}
>   
> +	new_total_nr += count_commands(&new_todo);
> +	new_todo.total_nr = new_total_nr;
> +
>   	/* Expand the commit IDs */
>   	todo_list_to_strbuf(r, &new_todo, &buf2, -1, 0);
>   	strbuf_swap(&new_todo.buf, &buf2);
>   	strbuf_release(&buf2);
> -	new_todo.total_nr -= new_todo.nr;

>   	if (todo_list_parse_insn_buffer(r, new_todo.buf.buf, &new_todo) < 0)
>   		BUG("invalid todo list after expanding IDs:\n%s",
>   		    new_todo.buf.buf);
> diff --git a/t/t3430-rebase-merges.sh b/t/t3430-rebase-merges.sh
> index f351701fec2..8da99a075dc 100755
> --- a/t/t3430-rebase-merges.sh
> +++ b/t/t3430-rebase-merges.sh
> @@ -517,4 +517,11 @@ test_expect_success '--rebase-merges with message matched with onto label' '
>   	EOF
>   '
>   
> +test_expect_success 'progress shows the correct total' '
> +	git checkout -b progress H &&
> +	git rebase --rebase-merges --force-rebase --verbose A 2> err &&
> +	grep "^Rebasing.*14.$" err >progress &&
> +	test_line_count = 14 progress
> +'
> +
>   test_done