Make encoding::warnings a no-op in 5.26

with a single warning at import time.

5 files changed, 56 insertions, 3 deletions

diff --git a/dist/encoding-warnings/lib/encoding/warnings.pm b/dist/encoding-warnings/lib/encoding/warnings.pm
index d5c4184130..3e76b0bc83 100644
--- a/dist/encoding-warnings/lib/encoding/warnings.pm
+++ b/dist/encoding-warnings/lib/encoding/warnings.pm
@@ -13,6 +13,20 @@ encoding::warnings - Warn on implicit encoding conversions
 This document describes version 0.11 of encoding::warnings, released
 June 5, 2007.
 
+=head1 NOTICE
+
+As of Perl 5.26.0, this module has no effect.  The internal Perl feature
+that was used to implement this module has been removed.  In recent years,
+much work has been done on the Perl core to eliminate discrepancies in the
+treatment of upgraded versus downgraded strings.  In addition, the
+L<encoding> pragma, which caused many of the problems, is no longer
+supported.  Thus, the warnings this module produced are no longer
+necessary.
+
+Hence, if you load this module on Perl 5.26.0, you will get one warning
+that the module is no longer supported; and the module will do nothing
+thereafter.
+
 =head1 SYNOPSIS
 
     use encoding::warnings; # or 'FATAL' to raise fatal exceptions
@@ -146,8 +160,16 @@ sub ASCII  () { 0 }
 sub LATIN1 () { 1 }
 sub FATAL  () { 2 }
 
-# Install a ${^ENCODING} handler if no other one are already in place.
 sub import {
+    if ($] >= 5.025003) {
+	require Carp;
+	Carp::cluck(
+	    "encoding::warnings is not supported on Perl 5.26.0 and later"
+	);
+	return;
+    }
+
+    # Install a ${^ENCODING} handler if no other one are already in place.
     my $class = shift;
     my $fatal = shift || '';
 
diff --git a/dist/encoding-warnings/t/1-warning.t b/dist/encoding-warnings/t/1-warning.t
index 9b04cb6767..fa0bb6e475 100644
--- a/dist/encoding-warnings/t/1-warning.t
+++ b/dist/encoding-warnings/t/1-warning.t
@@ -14,9 +14,25 @@ BEGIN {
 }
 
 use Test;
-BEGIN { plan tests => 2 }
-
 use strict;
+
+BEGIN {
+    if ("$]" >= 5.025) {
+	# Test the new almost-noop behaviour in new perls.
+	plan tests => 3;
+	my $w;
+	$SIG{__WARN__} = sub { $w .= shift };
+	require encoding::warnings;
+	ok $w, undef, 'no warning from requiring encoding::warnings';
+	ok(encoding::warnings->VERSION);
+	encoding::warnings->import;
+	ok $w, qr/^encoding::warnings is not supported /, 'import warning';
+	exit;
+    }
+    # else continue with your usual scheduled testing...
+    plan tests => 2;
+}
+
 use encoding::warnings;
 ok(encoding::warnings->VERSION);
 
diff --git a/dist/encoding-warnings/t/2-fatal.t b/dist/encoding-warnings/t/2-fatal.t
index ef001814df..d2928cd1f1 100644
--- a/dist/encoding-warnings/t/2-fatal.t
+++ b/dist/encoding-warnings/t/2-fatal.t
@@ -3,6 +3,10 @@
 # $Revision: #4 $ $Change: 1626 $ $DateTime: 2004-03-14T16:53:19.351256Z $
 
 BEGIN {
+    if ("$]" >= 5.025) {
+      print "1..0 # Skip: encoding::warnings not supported on perl 5.26\n";
+      exit 0;
+    }
     if (ord("A") != 65) {
       print "1..0 # Skip: Encode not working on EBCDIC\n";
       exit 0;
diff --git a/dist/encoding-warnings/t/3-normal.t b/dist/encoding-warnings/t/3-normal.t
index f0e6446a56..a66798bb73 100644
--- a/dist/encoding-warnings/t/3-normal.t
+++ b/dist/encoding-warnings/t/3-normal.t
@@ -1,3 +1,10 @@
+BEGIN {
+    if ("$]" >= 5.025) {
+      print "1..0 # Skip: encoding::warnings not supported on perl 5.26\n";
+      exit 0;
+    }
+}
+
 use Test;
 BEGIN { plan tests => 2 }
 
diff --git a/dist/encoding-warnings/t/4-lexical.t b/dist/encoding-warnings/t/4-lexical.t
index bdd9f21eec..0f6b4c1933 100644
--- a/dist/encoding-warnings/t/4-lexical.t
+++ b/dist/encoding-warnings/t/4-lexical.t
@@ -1,6 +1,10 @@
 use strict;
 use Test;
 BEGIN {
+    if ("$]" >= 5.025) {
+      print "1..0 # Skip: encoding::warnings not supported on perl 5.26\n";
+      exit 0;
+    }
     if (ord("A") != 65) {
       print "1..0 # Skip: Encode not working on EBCDIC\n";
       exit 0;