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From: Junio C Hamano <gitster@pobox.com>
To: Phillip Wood <phillip.wood@talktalk.net>
Cc: Git Mailing List <git@vger.kernel.org>,
	"Brian M. Carlson" <sandals@crustytoothpaste.net>,
	Eric Sunshine <sunshine@sunshineco.com>,
	Phillip Wood <phillip.wood@dunelm.org.uk>
Subject: Re: [PATCH v4 7/9] add -p: calculate offset delta for edited patches
Date: Thu, 01 Mar 2018 12:14:33 -0800
Message-ID: <xmqqwoyvft92.fsf@gitster-ct.c.googlers.com> (raw)
In-Reply-To: <20180301105103.24268-8-phillip.wood@talktalk.net>

Phillip Wood <phillip.wood@talktalk.net> writes:

> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>
> Recount the number of preimage and postimage lines in a hunk after it
> has been edited so any change in the number of insertions or deletions
> can be used to adjust the offsets of subsequent hunks. If an edited
> hunk is subsequently split then the offset correction will be lost. It
> would be possible to fix this if it is a problem, however the code
> here is still an improvement on the status quo for the common case
> where an edited hunk is applied without being split.
>
> This is also a necessary step to removing '--recount' and
> '--allow-overlap' from the invocation of 'git apply'. Before
> '--recount' can be removed the splitting and coalescing counting needs
> to be fixed to handle a missing newline at the end of a file. In order
> to remove '--allow-overlap' there needs to be i) some way of verifying
> the offset data in the edited hunk (probably by correlating the
> preimage (or postimage if the patch is going to be applied in reverse)
> lines of the edited and unedited versions to see if they are offset or
> if any leading/trailing context lines have been removed) and ii) a way of
> dealing with edited hunks that change context lines that are shared
> with neighbouring hunks.
>
> Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
> ---

Thanks for clear description of what is going on in the series.

> diff --git a/git-add--interactive.perl b/git-add--interactive.perl
> index 7a0a5896bb..0df0c2aa06 100755
> --- a/git-add--interactive.perl
> +++ b/git-add--interactive.perl
> @@ -938,13 +938,19 @@ sub coalesce_overlapping_hunks {
>  						parse_hunk_header($text->[0]);
>  		unless ($_->{USE}) {
>  			$ofs_delta += $o_cnt - $n_cnt;
> +			# If this hunk has been edited then subtract
> +			# the delta that is due to the edit.
> +			$_->{OFS_DELTA} and $ofs_delta -= $_->{OFS_DELTA};

The pattern

	<<conditional>> and <<statement with side effect>>;

is something you are newly introducing to this script.  I am not
sure if we want to see them.  I somehow find them harder to read
than the more straight-forward and naïve

	if (<<conditional>>) {
		<<statement with side effect>>;
	}


> +		# If this hunk was edited then adjust the offset delta
> +		# to reflect the edit.
> +		$_->{OFS_DELTA} and $ofs_delta += $_->{OFS_DELTA};

Likewise.

> +sub recount_edited_hunk {
> +	local $_;
> +	my ($oldtext, $newtext) = @_;
> +	my ($o_cnt, $n_cnt) = (0, 0);
> +	for (@{$newtext}[1..$#{$newtext}]) {
> +		my $mode = substr($_, 0, 1);
> +		if ($mode eq '-') {
> +			$o_cnt++;
> +		} elsif ($mode eq '+') {
> +			$n_cnt++;
> +		} elsif ($mode eq ' ') {
> +			$o_cnt++;
> +			$n_cnt++;
> +		}
> +	}
> +	my ($o_ofs, undef, $n_ofs, undef) =
> +					parse_hunk_header($newtext->[0]);
> +	$newtext->[0] = format_hunk_header($o_ofs, $o_cnt, $n_ofs, $n_cnt);
> +	my (undef, $orig_o_cnt, undef, $orig_n_cnt) =
> +					parse_hunk_header($oldtext->[0]);
> +	# Return the change in the number of lines inserted by this hunk
> +	return $orig_o_cnt - $orig_n_cnt - $o_cnt + $n_cnt;
> +}

OK.

> @@ -1114,25 +1144,32 @@ sub prompt_yesno {
>  }
>  
>  sub edit_hunk_loop {
> -	my ($head, $hunk, $ix) = @_;
> -	my $text = $hunk->[$ix]->{TEXT};
> +	my ($head, $hunks, $ix) = @_;
> +	my $hunk = $hunks->[$ix];
> +	my $text = $hunk->{TEXT};
> ...
> +		$newhunk->{OFS_DELTA} = recount_edited_hunk($text, $newtext);
> +		# If this hunk has already been edited then add the
> +		# offset delta of the previous edit to get the real
> +		# delta from the original unedited hunk.
> +		$hunk->{OFS_DELTA} and
> +				$newhunk->{OFS_DELTA} += $hunk->{OFS_DELTA};

Ahh, good point.


  reply index

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-13 10:44 [PATCH 0/4] Correct offsets of hunks when one is skipped Phillip Wood
2018-02-13 10:44 ` [PATCH 1/4] add -i: add function to format hunk header Phillip Wood
2018-02-13 10:44 ` [PATCH 2/4] t3701: add failing test for pathological context lines Phillip Wood
2018-02-13 20:35   ` Junio C Hamano
2018-02-13 10:44 ` [PATCH 3/4] add -p: Adjust offsets of subsequent hunks when one is skipped Phillip Wood
2018-02-13 10:44 ` [PATCH 4/4] add -p: calculate offset delta for edited patches Phillip Wood
2018-02-13 23:56 ` [PATCH 0/4] Correct offsets of hunks when one is skipped brian m. carlson
2018-02-19 13:01   ` Phillip Wood
2018-02-19 11:29 ` [PATCH v2 0/9] " Phillip Wood
2018-02-19 11:29   ` [PATCH v2 1/9] add -i: add function to format hunk header Phillip Wood
2018-02-20 18:21     ` Junio C Hamano
2018-02-19 11:29   ` [PATCH v2 2/9] t3701: indent here documents Phillip Wood
2018-02-19 18:36     ` Eric Sunshine
2018-02-19 11:29   ` [PATCH v2 3/9] t3701: use test_write_lines and write_script Phillip Wood
2018-02-19 18:47     ` Eric Sunshine
2018-02-20 17:19       ` Junio C Hamano
2018-02-21 11:26         ` Phillip Wood
2018-02-19 11:29   ` [PATCH v2 4/9] t3701: don't hard code sha1 hash values Phillip Wood
2018-02-19 18:52     ` Eric Sunshine
2018-02-20 17:39     ` Junio C Hamano
2018-02-21 11:42       ` Phillip Wood
2018-02-21 16:58         ` Junio C Hamano
2018-02-19 11:29   ` [PATCH v2 5/9] t3701: add failing test for pathological context lines Phillip Wood
2018-02-21 11:28     ` Phillip Wood
2018-02-19 11:29   ` [PATCH v2 6/9] add -p: Adjust offsets of subsequent hunks when one is skipped Phillip Wood
2018-02-19 11:29   ` [PATCH v2 7/9] add -p: calculate offset delta for edited patches Phillip Wood
2018-02-19 11:29   ` [PATCH v2 8/9] add -p: fix counting when splitting and coalescing Phillip Wood
2018-02-19 11:29   ` [PATCH v2 9/9] add -p: don't rely on apply's '--recount' option Phillip Wood
2018-02-20 18:50     ` Junio C Hamano
2018-02-27 11:03 ` [PATCH v3 0/9] Correct offsets of hunks when one is skipped Phillip Wood
2018-02-27 11:03   ` [PATCH v3 1/9] add -i: add function to format hunk header Phillip Wood
2018-02-27 11:03   ` [PATCH v3 2/9] t3701: indent here documents Phillip Wood
2018-02-27 22:35     ` Junio C Hamano
2018-02-28 11:00       ` Phillip Wood
2018-02-28 15:37         ` Junio C Hamano
2018-03-01 10:57           ` Phillip Wood
2018-03-01 15:58             ` Junio C Hamano
2018-02-27 11:03   ` [PATCH v3 3/9] t3701: use test_write_lines and write_script Phillip Wood
2018-02-27 11:03   ` [PATCH v3 4/9] t3701: don't hard code sha1 hash values Phillip Wood
2018-02-27 22:42     ` Junio C Hamano
2018-02-28 11:03       ` Phillip Wood
2018-02-28 11:10         ` Phillip Wood
2018-02-27 11:04   ` [PATCH v3 5/9] t3701: add failing test for pathological context lines Phillip Wood
2018-02-27 11:04   ` [PATCH v3 6/9] add -p: Adjust offsets of subsequent hunks when one is skipped Phillip Wood
2018-02-27 11:04   ` [PATCH v3 7/9] add -p: calculate offset delta for edited patches Phillip Wood
2018-02-27 11:04   ` [PATCH v3 8/9] add -p: fix counting when splitting and coalescing Phillip Wood
2018-02-27 11:04   ` [PATCH v3 9/9] add -p: don't rely on apply's '--recount' option Phillip Wood
2018-03-01 10:50 ` [PATCH v4 0/9] Correct offsets of hunks when one is skipped Phillip Wood
2018-03-01 10:50   ` [PATCH v4 1/9] add -i: add function to format hunk header Phillip Wood
2018-03-01 10:50   ` [PATCH v4 2/9] t3701: indent here documents Phillip Wood
2018-03-01 10:50   ` [PATCH v4 3/9] t3701: use test_write_lines and write_script Phillip Wood
2018-03-01 10:50   ` [PATCH v4 4/9] t3701: don't hard code sha1 hash values Phillip Wood
2018-03-02 15:55     ` SZEDER Gábor
2018-03-02 16:09       ` Junio C Hamano
2018-03-05 10:59         ` Phillip Wood
2018-03-05 12:32           ` SZEDER Gábor
2018-03-01 10:50   ` [PATCH v4 5/9] t3701: add failing test for pathological context lines Phillip Wood
2018-03-01 10:51   ` [PATCH v4 6/9] add -p: adjust offsets of subsequent hunks when one is skipped Phillip Wood
2018-03-01 10:51   ` [PATCH v4 7/9] add -p: calculate offset delta for edited patches Phillip Wood
2018-03-01 20:14     ` Junio C Hamano [this message]
2018-03-02 10:36       ` Phillip Wood
2018-03-01 10:51   ` [PATCH v4 8/9] add -p: fix counting when splitting and coalescing Phillip Wood
2018-03-01 20:29     ` Junio C Hamano
2018-03-02 10:48       ` Phillip Wood
2018-03-01 10:51   ` [PATCH v4 9/9] add -p: don't rely on apply's '--recount' option Phillip Wood
2018-03-01 20:30     ` Junio C Hamano
2018-03-02 10:49       ` Phillip Wood
2018-03-05 10:56 ` [PATCH v5 0/9] Correct offsets of hunks when one is skipped Phillip Wood
2018-03-05 10:56   ` [PATCH v5 1/9] add -i: add function to format hunk header Phillip Wood
2018-03-05 10:56   ` [PATCH v5 2/9] t3701: indent here documents Phillip Wood
2018-03-05 10:56   ` [PATCH v5 3/9] t3701: use test_write_lines and write_script Phillip Wood
2018-03-05 10:56   ` [PATCH v5 4/9] t3701: don't hard code sha1 hash values Phillip Wood
2018-03-05 10:56   ` [PATCH v5 5/9] t3701: add failing test for pathological context lines Phillip Wood
2018-03-05 10:56   ` [PATCH v5 6/9] add -p: adjust offsets of subsequent hunks when one is skipped Phillip Wood
2018-03-05 10:56   ` [PATCH v5 7/9] add -p: calculate offset delta for edited patches Phillip Wood
2018-03-05 10:56   ` [PATCH v5 8/9] add -p: fix counting when splitting and coalescing Phillip Wood
2018-03-05 10:56   ` [PATCH v5 9/9] add -p: don't rely on apply's '--recount' option Phillip Wood
2018-03-05 18:50   ` [PATCH v5 0/9] Correct offsets of hunks when one is skipped Junio C Hamano
2018-03-06 10:25     ` Phillip Wood

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