Teach "git add -i" to colorize whitespace errors

Rather than replicating the colorization logic of "git diff-files" we
rely on "git diff-files" itself. This guarantees consistent colorization
in and outside "git add -i".

Seeing as speed is not a concern here (the bottleneck is how fast the
user can read, not how fast "git diff-files" runs) we do this by
actually running it twice, once without color and once with.

In this way as the whitespace colorization provided by "git diff-files"
evolves (per-path attributes, new classes of whitespace error), "git
add -i" will automatically benefit from it and stay in synch.

Also, by working with two sets of diff output (an uncolorized one for
internal processing and a colorized one for display only) we minimize
the risk of regressions because the changes required to implement this
are minimally invasive.

Signed-off-by: Wincent Colaiuta <win@wincent.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 1019a72d6c5840a3a30a8435ac7e425080c0f594..0cdd80073bcbe0d9ffea30de85f9dda57f552e7f 100755 (executable)
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -525,40 +525,21 @@ sub add_untracked_cmd {
 sub parse_diff {
        my ($path) = @_;
        my @diff = run_cmd_pipe(qw(git diff-files -p --), $path);
-       my (@hunk) = { TEXT => [] };
-
-       for (@diff) {
-               if (/^@@ /) {
-                       push @hunk, { TEXT => [] };
-               }
-               push @{$hunk[-1]{TEXT}}, $_;
+       my @colored = ();
+       if ($diff_use_color) {
+               @colored = run_cmd_pipe(qw(git diff-files -p --color --), $path);
        }
-       return @hunk;
-}
-
-sub colored_diff_hunk {
-       my ($text) = @_;
-       # return the text, so that it can be passed to print()
-       my @ret;
-       for (@$text) {
-               if (!$diff_use_color) {
-                       push @ret, $_;
-                       next;
-               }
+       my (@hunk) = { TEXT => [], DISPLAY => [] };
 
-               if (/^\+/) {
-                       push @ret, colored($new_color, $_);
-               } elsif (/^\-/) {
-                       push @ret, colored($old_color, $_);
-               } elsif (/^\@/) {
-                       push @ret, colored($fraginfo_color, $_);
-               } elsif (/^ /) {
-                       push @ret, colored($normal_color, $_);
-               } else {
-                       push @ret, colored($metainfo_color, $_);
+       for (my $i = 0; $i < @diff; $i++) {
+               if ($diff[$i] =~ /^@@ /) {
+                       push @hunk, { TEXT => [], DISPLAY => [] };
                }
+               push @{$hunk[-1]{TEXT}}, $diff[$i];
+               push @{$hunk[-1]{DISPLAY}},
+                       ($diff_use_color ? $colored[$i] : $diff[$i]);
        }
-       return @ret;
+       return @hunk;
 }
 
 sub hunk_splittable {
@@ -578,9 +559,11 @@ sub parse_hunk_header {
 }
 
 sub split_hunk {
-       my ($text) = @_;
+       my ($text, $display) = @_;
        my @split = ();
-
+       if (!defined $display) {
+               $display = $text;
+       }
        # If there are context lines in the middle of a hunk,
        # it can be split, but we would need to take care of
        # overlaps later.
@@ -594,16 +577,19 @@ sub split_hunk {
                my $i = $hunk_start - 1;
                my $this = +{
                        TEXT => [],
+                       DISPLAY => [],
                        OLD => $o_ofs,
                        NEW => $n_ofs,
                        OCNT => 0,
                        NCNT => 0,
                        ADDDEL => 0,
                        POSTCTX => 0,
+                       USE => undef,
                };
 
                while (++$i < @$text) {
                        my $line = $text->[$i];
+                       my $display = $display->[$i];
                        if ($line =~ /^ /) {
                                if ($this->{ADDDEL} &&
                                    !defined $next_hunk_start) {
@@ -615,6 +601,7 @@ sub split_hunk {
                                        $next_hunk_start = $i;
                                }
                                push @{$this->{TEXT}}, $line;
+                               push @{$this->{DISPLAY}}, $display;
                                $this->{OCNT}++;
                                $this->{NCNT}++;
                                if (defined $next_hunk_start) {
@@ -637,6 +624,7 @@ sub split_hunk {
                                redo OUTER;
                        }
                        push @{$this->{TEXT}}, $line;
+                       push @{$this->{DISPLAY}}, $display;
                        $this->{ADDDEL}++;
                        if ($line =~ /^-/) {
                                $this->{OCNT}++;
@@ -661,9 +649,14 @@ sub split_hunk {
                            " +$n_ofs" .
                            (($n_cnt != 1) ? ",$n_cnt" : '') .
                            " @@\n");
+               my $display_head = $head;
                unshift @{$hunk->{TEXT}}, $head;
+               if ($diff_use_color) {
+                       $display_head = colored($fraginfo_color, $head);
+               }
+               unshift @{$hunk->{DISPLAY}}, $display_head;
        }
-       return map { $_->{TEXT} } @split;
+       return @split;
 }
 
 sub find_last_o_ctx {
@@ -794,7 +787,9 @@ sub patch_update_file {
        my ($ix, $num);
        my $path = shift;
        my ($head, @hunk) = parse_diff($path);
-       print colored_diff_hunk($head->{TEXT});
+       for (@{$head->{DISPLAY}}) {
+               print;
+       }
        $num = scalar @hunk;
        $ix = 0;
 
@@ -836,7 +831,9 @@ sub patch_update_file {
                if (hunk_splittable($hunk[$ix]{TEXT})) {
                        $other .= '/s';
                }
-               print colored_diff_hunk($hunk[$ix]{TEXT});
+               for (@{$hunk[$ix]{DISPLAY}}) {
+                       print;
+               }
                print colored $prompt_color, "Stage this hunk [y/n/a/d$other/?]? ";
                my $line = <STDIN>;
                if ($line) {
@@ -889,14 +886,12 @@ sub patch_update_file {
                                next;
                        }
                        elsif ($other =~ /s/ && $line =~ /^s/) {
-                               my @split = split_hunk($hunk[$ix]{TEXT});
+                               my @split = split_hunk($hunk[$ix]{TEXT}, $hunk[$ix]{DISPLAY});
                                if (1 < @split) {
                                        print colored $header_color, "Split into ",
                                        scalar(@split), " hunks.\n";
                                }
-                               splice(@hunk, $ix, 1,
-                                      map { +{ TEXT => $_, USE => undef } }
-                                      @split);
+                               splice (@hunk, $ix, 1, @split);
                                $num = scalar @hunk;
                                next;
                        }