Commands error when topic variable set to undef in compilation #2175
Description
- Mojolicious version: 9.30
- Perl version: 5.38
- Operating system: FreeBSD 14.0
Steps to reproduce the behavior
Loop at line 69 of Mojolicious::Commands encounters an undefined value if the topic variable $_ is set to undefined in the compilation phase of that command. Example (on a freshly generated app):
package MyApp::CLI::test;
use v5.38;
use parent 'Mojolicious::Command';
use constant description => 'blah blah';
sub run { ... }
$_ = undef;
Note: In the real project case I'm not setting that value explicitly, I'm using Beam::Wire at compilation phase which most likely does that one way or another because the observed behavior is the same.
Expected behavior
While polluting $_ is obviously erroneous, I believe Commands system should be resistant.
Actual behavior
I get these errors:
Use of uninitialized value $_ in substr at /root/perl5/perlbrew/perls/perl-5.38.0/lib/site_perl/5.38.0/Mojolicious/Commands.pm line 69.
substr outside of string at /root/perl5/perlbrew/perls/perl-5.38.0/lib/site_perl/5.38.0/Mojolicious/Commands.pm line 69.
Use of uninitialized value in hash element at /root/perl5/perlbrew/perls/perl-5.38.0/lib/site_perl/5.38.0/Mojolicious/Commands.pm line 69.
Can't call method "new" on an undefined value at /root/perl5/perlbrew/perls/perl-5.38.0/lib/site_perl/5.38.0/Mojolicious/Commands.pm line 69.
Rewriting the Mojolicious::Commands loop to this form fixes the issue for me:
for my $pkg (find_modules($ns), find_packages($ns)) {
next unless _command($pkg);
$all{substr $pkg, length "${ns}::"} //= $pkg->new->description
}