Avoid creating GV with NULL name when vivifying nameless scalars.

[p5sagit/p5-mst-13.2.git] / lib / vars.pm

diff --git a/lib/vars.pm b/lib/vars.pm
index 5256d11..ca2a08d 100644 (file)
--- a/lib/vars.pm
+++ b/lib/vars.pm
@@ -13,11 +13,20 @@ sub import {
     my $callpack = caller;
     my ($pack, @imports, $sym, $ch) = @_;
     foreach $sym (@imports) {
-       if ($sym =~ /::/) {
-           require Carp;
-           Carp::croak("Can't declare another package's variables");
-       }
         ($ch, $sym) = unpack('a1a*', $sym);
+       if ($sym =~ tr/A-Za-z_0-9//c) {
+           # time for a more-detailed check-up
+           if ($sym =~ /::/) {
+               require Carp;
+               Carp::croak("Can't declare another package's variables");
+           } elsif ($sym =~ /^\w+[[{].*[]}]$/) {
+               require Carp;
+               Carp::croak("Can't declare individual elements of hash or array");
+           } elsif ($^W and length($sym) == 1 and $sym !~ tr/a-zA-Z//) {
+               require Carp;
+               Carp::carp("No need to declare built-in vars");
+           }
+       }
         *{"${callpack}::$sym"} =
           (  $ch eq "\$" ? \$   {"${callpack}::$sym"}
            : $ch eq "\@" ? \@   {"${callpack}::$sym"}
@@ -26,7 +35,7 @@ sub import {
            : $ch eq "\&" ? \&   {"${callpack}::$sym"}
            : do {
                require Carp;
-               Carp::croak("'$ch$sym' is not a valid variable name\n");
+               Carp::croak("'$ch$sym' is not a valid variable name");
             });
     }
 };