assume "all" in "use warnings 'FATAL';" and related

Until now, the behavior of the statements

 use warnings "FATAL";
 use warnings "NONFATAL";
 no warnings "FATAL";

was unspecified and inconsistent. This change causes them to be handled
with an implied "all" at the end of the import list.

Tony Cook: fix AUTHORS formatting

1 files changed, 13 insertions, 0 deletions

diff --git a/pod/perllexwarn.pod b/pod/perllexwarn.pod
index 4a41789237..b4fed79ca1 100644
--- a/pod/perllexwarn.pod
+++ b/pod/perllexwarn.pod
@@ -405,6 +405,19 @@ except for those in the "syntax" category.
 
     use warnings FATAL => 'all', NONFATAL => 'syntax';
 
+As of Perl 5.20, instead of C<< use warnings FATAL => 'all'; >> you can
+use:
+
+    use v5.20;       # Perl 5.20 or greater is required for the following
+    use warnings 'FATAL';  # short form of "use warnings FATAL => 'all';"
+
+If you want your program to be compatible with versions of Perl before
+5.20, you must use C<< use warnings FATAL => 'all'; >> instead.  (In
+previous versions of Perl, the behavior of the statements
+C<< use warnings 'FATAL'; >>, C<< use warnings 'NONFATAL'; >> and
+C<< no warnings 'FATAL'; >> was unspecified; they did not behave as if
+they included the C<< => 'all' >> portion.  As of 5.20, they do.)
+
 B<NOTE:> Users of FATAL warnings, especially
 those using C<< FATAL => 'all' >>
 should be fully aware that they are risking future portability of their