On 01/03/18 20:14, Junio C Hamano wrote:
> Phillip Wood <phillip.w...@talktalk.net> writes:
>
>> From: Phillip Wood <phillip.w...@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.w...@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>>;
> }
>
Fair enough, I think I was suffering from brace fatigue when I wrote it,
if you can hold off merging this into next I'll re-roll with "if's"
instead of "and's".
>> + # 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.
>
