The patch does the following:

- Nix the unneccessary diagnostics line
- Quell -w warnings if the first ENV doesn't exist
- While zh_CN means euc-cn, zh_TW almost invariably mean big5, as euc-tw
  is too baroque and bloated for daily use (and for perl core inclusion).
- "Cannot figure out an encoding to use" when locale is 'C' is rendered
  non-fatal.
- Consequently, the ^OPEN bits is set only when needed.

p4raw-id: //depot/perl@15142

diff --git a/lib/open.pm b/lib/open.pm
index b535d88..e480c13 100644 (file)
--- a/lib/open.pm
+++ b/lib/open.pm
@@ -16,10 +16,10 @@ sub _get_locale_encoding {
            I18N::Langinfo->import(qw(langinfo CODESET));
            $locale_encoding = langinfo(CODESET());
        };
-       unless ($@) {
-           print "# locale_encoding = $locale_encoding\n";
-       }
        my $country_language;
+
+       no warnings 'uninitialized';
+
         if (not $locale_encoding && in_locale()) {
            if ($ENV{LC_ALL} =~ /^([^.]+)\.([^.]+)$/) {
                ($country_language, $locale_encoding) = ($1, $2);
@@ -45,8 +45,10 @@ sub _get_locale_encoding {
                $locale_encoding = 'euc-jp';
            } elsif ($country_language =~ /^ko_KR|korean?$/i) {
                $locale_encoding = 'euc-kr';
+           } elsif ($country_language =~ /^zh_CN|chin(?:a|ese)?$/i) {
+               $locale_encoding = 'euc-cn';
            } elsif ($country_language =~ /^zh_TW|taiwan(?:ese)?$/i) {
-               $locale_encoding = 'euc-tw';
+               $locale_encoding = 'big5';
            }
            croak "Locale encoding 'euc' too ambiguous"
                if $locale_encoding eq 'euc';
@@ -75,7 +77,7 @@ sub import {
                use Encode;
                _get_locale_encoding()
                    unless defined $locale_encoding;
-               croak "Cannot figure out an encoding to use"
+               (carp("Cannot figure out an encoding to use"), last)
                    unless defined $locale_encoding;
                if ($locale_encoding =~ /^utf-?8$/i) {
                    $layer = "utf8";
@@ -106,7 +108,7 @@ sub import {
            croak "Unknown discipline class '$type'";
        }
     }
-    ${^OPEN} = join("\0",$in,$out);
+    ${^OPEN} = join("\0",$in,$out) if $in or $out;
 }
 
 1;