@matheusbsbs / matheus-bagliano / commits / 2b8ea7f3c7

add -p: calculate offset delta for edited patches

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> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Phillip Wood committed Mar 5, 2018 at 10:56 UTC 2b8ea7f3c7d8dfd4f1eddaef6688b51f8106767e
2 files changed +51 -10
git-add--interactive.perl
+50 -9
@@ -938,6 +938,11 @@ sub coalesce_overlapping_hunks {
938 parse_hunk_header($text->[0]);
939 unless ($_->{USE}) {
940 $ofs_delta += $o_cnt - $n_cnt;
941 + # If this hunk has been edited then subtract
942 + # the delta that is due to the edit.
943 + if ($_->{OFS_DELTA}) {
944 + $ofs_delta -= $_->{OFS_DELTA};
945 + }
946 next;
947 }
948 if ($ofs_delta) {
@@ -945,6 +950,11 @@ sub coalesce_overlapping_hunks {
950 $_->{TEXT}->[0] = format_hunk_header($o_ofs, $o_cnt,
951 $n_ofs, $n_cnt);
952 }
953 + # If this hunk was edited then adjust the offset delta
954 + # to reflect the edit.
955 + if ($_->{OFS_DELTA}) {
956 + $ofs_delta += $_->{OFS_DELTA};
957 + }
958 if (defined $last_o_ctx &&
959 $o_ofs <= $last_o_ctx &&
960 !$_->{DIRTY} &&
@@ -1016,6 +1026,30 @@ marked for discarding."),
1026 marked for applying."),
1027 );
1028
1029 +sub recount_edited_hunk {
1030 + local $_;
1031 + my ($oldtext, $newtext) = @_;
1032 + my ($o_cnt, $n_cnt) = (0, 0);
1033 + for (@{$newtext}[1..$#{$newtext}]) {
1034 + my $mode = substr($_, 0, 1);
1035 + if ($mode eq '-') {
1036 + $o_cnt++;
1037 + } elsif ($mode eq '+') {
1038 + $n_cnt++;
1039 + } elsif ($mode eq ' ') {
1040 + $o_cnt++;
1041 + $n_cnt++;
1042 + }
1043 + }
1044 + my ($o_ofs, undef, $n_ofs, undef) =
1045 + parse_hunk_header($newtext->[0]);
1046 + $newtext->[0] = format_hunk_header($o_ofs, $o_cnt, $n_ofs, $n_cnt);
1047 + my (undef, $orig_o_cnt, undef, $orig_n_cnt) =
1048 + parse_hunk_header($oldtext->[0]);
1049 + # Return the change in the number of lines inserted by this hunk
1050 + return $orig_o_cnt - $orig_n_cnt - $o_cnt + $n_cnt;
1051 +}
1052 +
1053 sub edit_hunk_manually {
1054 my ($oldtext) = @_;
1055
@@ -1114,25 +1148,32 @@ sub prompt_yesno {
1148 }
1149
1150 sub edit_hunk_loop {
1117 - my ($head, $hunk, $ix) = @_;
1118 - my $text = $hunk->[$ix]->{TEXT};
1151 + my ($head, $hunks, $ix) = @_;
1152 + my $hunk = $hunks->[$ix];
1153 + my $text = $hunk->{TEXT};
1154
1155 while (1) {
1121 - $text = edit_hunk_manually($text);
1122 - if (!defined $text) {
1156 + my $newtext = edit_hunk_manually($text);
1157 + if (!defined $newtext) {
1158 return undef;
1159 }
1160 my $newhunk = {
1126 - TEXT => $text,
1127 - TYPE => $hunk->[$ix]->{TYPE},
1161 + TEXT => $newtext,
1162 + TYPE => $hunk->{TYPE},
1163 USE => 1,
1164 DIRTY => 1,
1165 };
1166 + $newhunk->{OFS_DELTA} = recount_edited_hunk($text, $newtext);
1167 + # If this hunk has already been edited then add the
1168 + # offset delta of the previous edit to get the real
1169 + # delta from the original unedited hunk.
1170 + $hunk->{OFS_DELTA} and
1171 + $newhunk->{OFS_DELTA} += $hunk->{OFS_DELTA};
1172 if (diff_applies($head,
1132 - @{$hunk}[0..$ix-1],
1173 + @{$hunks}[0..$ix-1],
1174 $newhunk,
1134 - @{$hunk}[$ix+1..$#{$hunk}])) {
1135 - $newhunk->{DISPLAY} = [color_diff(@{$text})];
1175 + @{$hunks}[$ix+1..$#{$hunks}])) {
1176 + $newhunk->{DISPLAY} = [color_diff(@{$newtext})];
1177 return $newhunk;
1178 }
1179 else {
t/t3701-add-interactive.sh
+1 -1
@@ -504,7 +504,7 @@ test_expect_success 'add -p works with pathological context lines' '
504 test_cmp expected-1 actual
505 '
506
507 -test_expect_failure 'add -p patch editing works with pathological context lines' '
507 +test_expect_success 'add -p patch editing works with pathological context lines' '
508 git reset &&
509 # n q q below is in case edit fails
510 printf "%s\n" e y n q q |