#!/usr/bin/perl
#
# Wrapper to call ispell on mail messages, ignoring quoted portions
# and signatures.
# By Brendan O'Dea <bod@debian.org>, public domain.
# Usage: set ispell = /usr/lib/mutt/mailspell
#

use IO::File;
use POSIX 'tmpnam';
use File::Copy 'move';

$0 =~ s#.*/##;

my $ISPELL = 'ispell';
my $DIFF   = 'diff';
my $ED     = 'ed';

# make sure that we don't inherit SIGCHLD
$SIG{CHLD} = 'DEFAULT';

# ignore -x ispell option
shift if $ARGV[0] eq '-x';
die "Usage: $0 [-x] FILE\n" unless @ARGV == 1;

my $msg = $ARGV[0];

# create temporary files
my (%orig, %ed);

END {
    unlink $ed{path}   if $ed{path};
    unlink $orig{path} if $orig{path};
}

foreach (\%orig, \%ed) {
    $_->{path} = tmpnam;
    $_->{fd} = IO::File->new($_->{path}, O_RDWR|O_CREAT|O_EXCL, 0600)
		or die "$0: can't create $_->{path} ($!)";
}

while (<>) {
    # stop at sigdashes
    last if /^-- \n/;

    # drop quoted text and attribution
    $orig{fd}->print($_) unless /^>/ or /^On \w{3}, \w{3} \d{2}, \d{4} at \d/;
}

$orig{fd}->close;

my $pid = fork;
die "$0: can't fork ($!)\n" unless defined $pid;
unless ($pid) {
    open STDOUT, '>&=' . $ed{fd}->fileno
		or die "$0: can't dup stdout to ed script ($!)\n";
    $ed{fd}->close;
    exec $DIFF, '-e', $orig{path}, $msg;
    die "$0: can't exec $DIFF ($!)\n";
}

die "$0: can't reap child ($!)\n" unless wait == $pid;
system $ISPELL, '-x', $orig{path}
    and die "$0: problem with $ISPELL ($?)\n";

$ed{fd}->seek(0, SEEK_END);
$ed{fd}->print("w\nq\n");
$ed{fd}->seek(0, SEEK_SET);

open STDIN, '<&=' . $ed{fd}->fileno
    or die "$0: can't dup stdin from ed script ($!)\n";

system $ED, '-s', $orig{path} and die "$0: problem with $ED ($?)\n";
move $orig{path}, $msg        or  die "$0: can't replace $msg ($!)\n";
delete $orig{path};

1;