Package: libgraph-perl
Version: 1:0.9716-1
Severity: grave
The attached script, which tests the transitive closure function,
prints this output on testing:
input: A-NOTA,B-A,B-NOTA
Use of uninitialized value $_ in exists at /usr/share/perl5/Graph.pm line 362.
Use of uninitialized value $_ in exists at /usr/share/perl5/Graph.pm line 362.
output: A-A,A-B,B-B,NOTA-NOTA
output: A-B,NOTA-NOTA
The correct output, as seen on buster:
input: A-NOTA,B-A,B-NOTA
output: A-A,A-NOTA,B-A,B-B,B-NOTA,NOTA-NOTA
output: A-NOTA,B-A,B-NOTA,NOTA-NOTA
Empirically, the delete_vertex call is necessary for the repro.
I think this is certainly release critical. I chose "grave" rather
than "serious" since this can produce corrupted output in data
processing situations, where the corrupted output might not be
detected.
In my Debian tally sheet processing program
https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=appendix-a6.git
(`compute`, there), this can produce totally wrong answers for the
winner of votes.
Ian.
#!/usr/bin/perl -w
use strict;
use Graph::Directed;
my $input = Graph::Directed->new;
foreach my $e (qw(
A-C
A-NOTA
B-A
B-C
B-NOTA
)) {
my ($x,$y) = split /-/, $e;
$input->add_edge($x,$y);
}
$input->delete_vertex('C');
print "input: $input\n";
my $output = $input->transitive_closure();
print "output: $output\n";
foreach my $x (qw(A B C N)) {
$output->delete_edge($x,$x);
}
print "output: $output\n";
--
Ian Jackson <[email protected]> These opinions are my own.
Pronouns: they/he. If I emailed you from @fyvzl.net or @evade.org.uk,
that is a private address which bypasses my fierce spamfilter.
