Revert base.pm's dot-in-INC changes.

This reverts:
    458470f62360040dcd4b5a55c8ba07503e1af5fc
    362f3f748cb84934a072fadbfb8b51090e2f9afe
    bca552795994a553e07b38a6f82a233533919926
and the base.pm part of
    8901ddee94b1bc3764b4278d1cb26bed30bc2605

This commit removes all the recent stuff that made base.pm localise
@INC and remove a trailing '.'.

This is because perl 5.26.0 will be released with  '.' in @INC disabled by
default.

See RT #128769.

3 files changed, 2 insertions, 39 deletions

diff --git a/MANIFEST b/MANIFEST
index c7a4dd6074..185766cbb5 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -3234,7 +3234,6 @@ dist/base/t/fields.t		See if fields work
 dist/base/t/fields-5_6_0.t	See if fields work
 dist/base/t/fields-5_8_0.t	See if fields work
 dist/base/t/fields-base.t	See if fields work
-dist/base/t/incdot.t		Test how base.pm handles '.' in @INC
 dist/base/t/isa.t		See if base's behaviour doesn't change
 dist/base/t/lib/Broken.pm	Test module for base.pm
 dist/base/t/lib/Dummy.pm	Test module for base.pm
diff --git a/dist/base/lib/base.pm b/dist/base/lib/base.pm
index 38c91c731c..f7a2480381 100644
--- a/dist/base/lib/base.pm
+++ b/dist/base/lib/base.pm
@@ -97,11 +97,7 @@ sub import {
             {
                 local $SIG{__DIE__};
                 my $fn = _module_to_filename($base);
-                local @INC = @INC;
-                pop @INC if my $dotty = $INC[-1] eq '.';
-                eval {
-                    require $fn
-                };
+                eval { require $fn };
                 # Only ignore "Can't locate" errors from our eval require.
                 # Other fatal errors (syntax etc) must be reported.
                 #
@@ -115,24 +111,11 @@ sub import {
                 unless (%{"$base\::"}) {
                     require Carp;
                     local $" = " ";
-                    my $e = <<ERROR;
+                    Carp::croak(<<ERROR);
 Base class package "$base" is empty.
     (Perhaps you need to 'use' the module which defines that package first,
     or make that module available in \@INC (\@INC contains: @INC).
 ERROR
-                    if ($dotty && -e $fn) {
-                        $e .= <<ERROS;
-    The file $fn does exist in the current directory.  But note
-    that base.pm, when loading a module, now ignores the current working
-    directory if it is the last entry in \@INC.  If your software worked on
-    previous versions of Perl, the best solution is to use FindBin to
-    detect the path properly and to add that path to \@INC.  As a last
-    resort, you can re-enable looking in the current working directory by
-    adding "use lib '.'" to your code.
-ERROS
-                    }
-                    $e =~ s/\n\z/)\n/;
-                    Carp::croak($e);
                 }
                 $sigdie = $SIG{__DIE__} || undef;
             }
diff --git a/dist/base/t/incdot.t b/dist/base/t/incdot.t
deleted file mode 100644
index 1619492250..0000000000
--- a/dist/base/t/incdot.t
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/usr/bin/perl -w
-
-use strict;
-
-use base ();
-
-use Test::More tests => 2;
-
-if ($INC[-1] ne '.') { push @INC, '.' }
-
-my $inc = quotemeta "@INC[0..$#INC-1]";
-
-eval { 'base'->import("foo") };
-like $@, qr/\@INC contains: $inc\).\)/,
-    'Error does not list final dot in @INC (or mention use lib)';
-eval { 'base'->import('t::lib::Dummy') };
-like $@, qr<\@INC contains: $inc\).\n(?x:
-           )    The file t/lib/Dummy\.pm does exist in the current direct>,
-    'special cur dir message for existing files in . that are ignored';