Warning for some usages of Math.rand [rt.cpan.org #70957]

[atoomic]

Migrated from rt.cpan.org#70957 (status was 'open')

Requestors:

• SREZIC@cpan.org

Attachments:

• tt2-math-rand.diff

From srezic@cpan.org on 2011-09-14 07:39:07:
The perl core functions rand and srand may be called without arguments. When using the same functions without arguments in the TT2 plugin Math, a warning may appear:

$ perl -l -w -MTemplate -e '$t=Template->new;$t->process(\"[% USE Math; Math.rand %]",{})or die $t->error'
Use of uninitialized value $_[0] in rand at /usr/lib/perl5/Template/Plugin/Math.pm line 55.
0.509199773267941

Probably the plugin methods rand() and srand() should check if there's
anything in @_ and call the core function differently.

Regards,
Slaven

From srezic@cpan.org on 2011-09-14 07:42:20:

Attached a patch to fix the problem, together with a new test script
(the test case did not fit in the existing t/math.t).

Regards,
Slaven

[toddr]

diff --git c/MANIFEST w/MANIFEST
index ea00da1..1d2177b 100644
--- c/MANIFEST
+++ w/MANIFEST
@@ -126,6 +126,7 @@ t/lib/Template/Plugin/Simple.pm
 t/list.t
 t/macro.t
 t/math.t
+t/math2.t
 t/object.t
 t/output.t
 t/parser.t
diff --git c/lib/Template/Plugin/Math.pm w/lib/Template/Plugin/Math.pm
index ff40004..5482e91 100644
--- c/lib/Template/Plugin/Math.pm
+++ w/lib/Template/Plugin/Math.pm
@@ -52,10 +52,10 @@ sub hex   { shift; CORE::hex($_[0]);          }
 sub int   { shift; CORE::int($_[0]);          }
 sub log   { shift; CORE::log($_[0]);          }
 sub oct   { shift; CORE::oct($_[0]);          }
-sub rand  { shift; CORE::rand($_[0]);         }
+sub rand  { shift; @_ ? CORE::rand($_[0]) : CORE::rand(); }
 sub sin   { shift; CORE::sin($_[0]);          }
 sub sqrt  { shift; CORE::sqrt($_[0]);         }
-sub srand { shift; CORE::srand($_[0]);        }
+sub srand { shift; @_ ? CORE::srand($_[0]) : CORE::srand(); }
 
 # Use the Math::TrulyRandom module
 # XXX This is *sloooooooowwwwwwww*
diff --git c/t/math2.t w/t/math2.t
new file mode 100644
index 0000000..9d7bfa4
--- /dev/null
+++ w/t/math2.t
@@ -0,0 +1,19 @@
+use strict;
+use Test::More;
+use Template;
+
+plan tests => 1;
+
+my @warnings;
+local $SIG{__WARN__} = sub { push @warnings, @_ };
+my $t = Template->new;
+my $out;
+$t->process(\<<EOF, {}, \$out) or die $t->error;
+[% USE Math -%]
+rand  with arg:    [% Math.rand(1000000) %]
+rand  without arg: [% Math.rand %]
+srand with arg:    [% Math.srand(1000000) %]
+srand without arg: [% Math.srand %]
+EOF
+#diag $out;
+is_deeply \@warnings, [], 'No warnings when calling rand/srand without arg';