[perl5.git] / t / mro / basic.t

#!./perl

BEGIN {
    chdir 't' if -d 't';
    @INC = '../lib';
    require q(./test.pl);
}

use strict;
use warnings;

plan(tests => 61);

require mro;

{
    package MRO_A;
    our @ISA = qw//;
    package MRO_B;
    our @ISA = qw//;
    package MRO_C;
    our @ISA = qw//;
    package MRO_D;
    our @ISA = qw/MRO_A MRO_B MRO_C/;
    package MRO_E;
    our @ISA = qw/MRO_A MRO_B MRO_C/;
    package MRO_F;
    our @ISA = qw/MRO_D MRO_E/;
}

my @MFO_F_DFS = qw/MRO_F MRO_D MRO_A MRO_B MRO_C MRO_E/;
my @MFO_F_C3 = qw/MRO_F MRO_D MRO_E MRO_A MRO_B MRO_C/;
is(mro::get_mro('MRO_F'), 'dfs');
ok(eq_array(
    mro::get_linear_isa('MRO_F'), \@MFO_F_DFS
));

ok(eq_array(mro::get_linear_isa('MRO_F', 'dfs'), \@MFO_F_DFS));
ok(eq_array(mro::get_linear_isa('MRO_F', 'c3'), \@MFO_F_C3));
eval{mro::get_linear_isa('MRO_F', 'C3')};
like($@, qr/^Invalid mro name: 'C3'/);

mro::set_mro('MRO_F', 'c3');
is(mro::get_mro('MRO_F'), 'c3');
ok(eq_array(
    mro::get_linear_isa('MRO_F'), \@MFO_F_C3
));

ok(eq_array(mro::get_linear_isa('MRO_F', 'dfs'), \@MFO_F_DFS));
ok(eq_array(mro::get_linear_isa('MRO_F', 'c3'), \@MFO_F_C3));
eval{mro::get_linear_isa('MRO_F', 'C3')};
like($@, qr/^Invalid mro name: 'C3'/);

my @isarev = sort { $a cmp $b } @{mro::get_isarev('MRO_B')};
ok(eq_array(
    \@isarev,
    [qw/MRO_D MRO_E MRO_F/]
));

ok(!mro::is_universal('MRO_B'));

@UNIVERSAL::ISA = qw/MRO_F/;
ok(mro::is_universal('MRO_B'));

@UNIVERSAL::ISA = ();
ok(!mro::is_universal('MRO_B'));

# is_universal, get_mro, and get_linear_isa should
# handle non-existent packages sanely
ok(!mro::is_universal('Does_Not_Exist'));
is(mro::get_mro('Also_Does_Not_Exist'), 'dfs');
ok(eq_array(
    mro::get_linear_isa('Does_Not_Exist_Three'),
    [qw/Does_Not_Exist_Three/]
));

# Assigning @ISA via globref
{
    package MRO_TestBase;
    sub testfunc { return 123 }
    package MRO_TestOtherBase;
    sub testfunctwo { return 321 }
    package MRO_M; our @ISA = qw/MRO_TestBase/;
}
*MRO_N::ISA = *MRO_M::ISA;
is(eval { MRO_N->testfunc() }, 123);

# XXX TODO (when there's a way to backtrack through a glob's aliases)
# push(@MRO_M::ISA, 'MRO_TestOtherBase');
# is(eval { MRO_N->testfunctwo() }, 321);

# Simple DESTROY Baseline
{
    my $x = 0;
    my $obj;

    {
        package DESTROY_MRO_Baseline;
        sub new { bless {} => shift }
        sub DESTROY { $x++ }

        package DESTROY_MRO_Baseline_Child;
        our @ISA = qw/DESTROY_MRO_Baseline/;
    }

    $obj = DESTROY_MRO_Baseline->new();
    undef $obj;
    is($x, 1);

    $obj = DESTROY_MRO_Baseline_Child->new();
    undef $obj;
    is($x, 2);
}

# Dynamic DESTROY
{
    my $x = 0;
    my $obj;

    {
        package DESTROY_MRO_Dynamic;
        sub new { bless {} => shift }

        package DESTROY_MRO_Dynamic_Child;
        our @ISA = qw/DESTROY_MRO_Dynamic/;
    }

    $obj = DESTROY_MRO_Dynamic->new();
    undef $obj;
    is($x, 0);

    $obj = DESTROY_MRO_Dynamic_Child->new();
    undef $obj;
    is($x, 0);

    no warnings 'once';
    *DESTROY_MRO_Dynamic::DESTROY = sub { $x++ };

    $obj = DESTROY_MRO_Dynamic->new();
    undef $obj;
    is($x, 1);

    $obj = DESTROY_MRO_Dynamic_Child->new();
    undef $obj;
    is($x, 2);
}

# clearing @ISA in different ways
#  some are destructive to the package, hence the new
#  package name each time
{
    no warnings 'uninitialized';
    {
        package ISACLEAR;
        our @ISA = qw/XX YY ZZ/;
    }
    # baseline
    ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR XX YY ZZ/]));

    # this looks dumb, but it preserves existing behavior for compatibility
    #  (undefined @ISA elements treated as "main")
    $ISACLEAR::ISA[1] = undef;
    ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR XX main ZZ/]));

    # undef the array itself
    undef @ISACLEAR::ISA;
    ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR/]));

    # Now, clear more than one package's @ISA at once
    {
        package ISACLEAR1;
        our @ISA = qw/WW XX/;

        package ISACLEAR2;
        our @ISA = qw/YY ZZ/;
    }
    # baseline
    ok(eq_array(mro::get_linear_isa('ISACLEAR1'),[qw/ISACLEAR1 WW XX/]));
    ok(eq_array(mro::get_linear_isa('ISACLEAR2'),[qw/ISACLEAR2 YY ZZ/]));
    (@ISACLEAR1::ISA, @ISACLEAR2::ISA) = ();

    ok(eq_array(mro::get_linear_isa('ISACLEAR1'),[qw/ISACLEAR1/]));
    ok(eq_array(mro::get_linear_isa('ISACLEAR2'),[qw/ISACLEAR2/]));

    # [perl #49564]  This is a pretty obscure way of clearing @ISA but
    # it tests a regression that affects XS code calling av_clear too.
    {
        package ISACLEAR3;
        our @ISA = qw/WW XX/;
    }
    ok(eq_array(mro::get_linear_isa('ISACLEAR3'),[qw/ISACLEAR3 WW XX/]));
    {
        package ISACLEAR3;
        reset 'I';
    }
    ok(eq_array(mro::get_linear_isa('ISACLEAR3'),[qw/ISACLEAR3/]));
}

# Check that recursion bails out "cleanly" in a variety of cases
# (as opposed to say, bombing the interpreter or something)
{
    my @recurse_codes = (
        '@MRO_R1::ISA = "MRO_R2"; @MRO_R2::ISA = "MRO_R1";',
        '@MRO_R3::ISA = "MRO_R4"; push(@MRO_R4::ISA, "MRO_R3");',
        '@MRO_R5::ISA = "MRO_R6"; @MRO_R6::ISA = qw/XX MRO_R5 YY/;',
        '@MRO_R7::ISA = "MRO_R8"; push(@MRO_R8::ISA, qw/XX MRO_R7 YY/)',
    );
    foreach my $code (@recurse_codes) {
        eval $code;
        ok($@ =~ /Recursive inheritance detected/);
    }
}

# Check that SUPER caches get invalidated correctly
{
    {
        package SUPERTEST;
        sub new { bless {} => shift }
        sub foo { $_[1]+1 }

        package SUPERTEST::MID;
        our @ISA = 'SUPERTEST';

        package SUPERTEST::KID;
        our @ISA = 'SUPERTEST::MID';
        sub foo { my $s = shift; $s->SUPER::foo(@_) }

        package SUPERTEST::REBASE;
        sub foo { $_[1]+3 }
    }

    my $stk_obj = SUPERTEST::KID->new();
    is($stk_obj->foo(1), 2);
    { no warnings 'redefine';
      *SUPERTEST::foo = sub { $_[1]+2 };
    }
    is($stk_obj->foo(2), 4);
    @SUPERTEST::MID::ISA = 'SUPERTEST::REBASE';
    is($stk_obj->foo(3), 6);
}

{ 
  {
    # assigning @ISA via arrayref to globref RT 60220
    package P1;
    sub new { bless {}, shift }
    
    package P2;
  }
  *{P2::ISA} = [ 'P1' ];
  my $foo = P2->new;
  ok(!eval { $foo->bark }, "no bark method");
  no warnings 'once';  # otherwise it'll bark about P1::bark used only once
  *{P1::bark} = sub { "[bark]" };
  is(scalar eval { $foo->bark }, "[bark]", "can bark now");
}

{
  # assigning @ISA via arrayref then modifying it RT 72866
  {
    package Q1;
    sub foo {  }

    package Q2;
    sub bar { }

    package Q3;
  }
  push @Q3::ISA, "Q1";
  can_ok("Q3", "foo");
  *Q3::ISA = [];
  push @Q3::ISA, "Q1";
  can_ok("Q3", "foo");
  *Q3::ISA = [];
  push @Q3::ISA, "Q2";
  can_ok("Q3", "bar");
  ok(!Q3->can("foo"), "can't call foo method any longer");
}

{
    # test mro::method_changed_in
    my $count = mro::get_pkg_gen("MRO_A");
    mro::method_changed_in("MRO_A");
    my $count_new = mro::get_pkg_gen("MRO_A");

    is($count_new, $count + 1);
}

{
    # test if we can call mro::invalidate_all_method_caches;
    eval {
        mro::invalidate_all_method_caches();
    };
    is($@, "");
}

{
    # @main::ISA
    no warnings 'once';
    @main::ISA = 'parent';
    my $output = '';
    *parent::do = sub { $output .= 'parent' };
    *parent2::do = sub { $output .= 'parent2' };
    main->do;
    @main::ISA = 'parent2';
    main->do;
    is $output, 'parentparent2', '@main::ISA is magical';
}

{
    # Undefining *ISA, then modifying @ISA
    # This broke Class::Trait. See [perl #79024].
    {package Class::Trait::Base}
    no strict 'refs';
    undef   *{"Extra::TSpouse::ISA"};
    'Extra::TSpouse'->isa('Class::Trait::Base'); # cache the mro
    unshift @{"Extra::TSpouse::ISA"}, 'Class::Trait::Base';
    ok 'Extra::TSpouse'->isa('Class::Trait::Base'),
     'a isa b after undef *a::ISA and @a::ISA modification';
}

{
    # Deleting $package::{ISA}
    # Broken in 5.10.0; fixed in 5.13.7
    @Blength::ISA = 'Bladd';
    delete $Blength::{ISA};
    ok !Blength->isa("Bladd"), 'delete $package::{ISA}';
}

{
    # Undefining stashes
    @Thrext::ISA = "Thwit";
    @Thwit::ISA = "Sile";
    undef %Thwit::;
    ok !Thrext->isa('Sile'), 'undef %package:: updates subclasses';
}

{
    # Obliterating @ISA via glob assignment
    # Broken in 5.14.0; fixed in 5.17.2
    @Gwythaint::ISA = "Fantastic::Creature";
    undef *This_glob_haD_better_not_exist; # paranoia; must have no array
    *Gwythaint::ISA = *This_glob_haD_better_not_exist;
    ok !Gwythaint->isa("Fantastic::Creature"),
       'obliterating @ISA via glob assignment';
}

{
    # Autovivifying @ISA via @{*ISA}
    no warnings;
    undef *fednu::ISA;
    @{*fednu::ISA} = "pyfg";
    ok +fednu->isa("pyfg"), 'autovivifying @ISA via *{@ISA}';
}

{
    sub Detached::method;
    my $h = delete $::{"Detached::"};
    eval { local *Detached::method };
    is $@, "", 'localising gv-with-cv belonging to detached package';
}

{
    # *ISA localisation
    @il::ISA = "ilsuper";
    sub ilsuper::can { "puree" }
    sub il::tomatoes;
    {
        local *il::ISA;
        is +il->can("tomatoes"), \&il::tomatoes, 'local *ISA';
    }
    is "il"->can("tomatoes"), "puree", 'local *ISA unwinding';
    {
        local *il::ISA = [];
        is +il->can("tomatoes"), \&il::tomatoes, 'local *ISA = []';
    }
    is "il"->can("tomatoes"), "puree", 'local *ISA=[] unwinding';
}

# Changes to UNIVERSAL::DESTROY should not leave stale DESTROY caches
# (part of #114864)
our $destroy_output;
sub UNIVERSAL::DESTROY { $destroy_output = "old" }
my $x = bless[];
undef $x; # cache the DESTROY method
undef *UNIVERSAL::DESTROY;
*UNIVERSAL::DESTROY = sub { $destroy_output = "new" };
$x = bless[];
undef $x; # should use the new DESTROY
is $destroy_output, "new",
    'Changes to UNIVERSAL::DESTROY invalidate DESTROY caches';
undef *UNIVERSAL::DESTROY;

{
    no warnings 'uninitialized';
    $#_119433::ISA++;
    pass "no crash when ISA contains nonexistent elements";
}
Commit	Line	Data
e1a479c5 BB	1	#!./perl
e1a479c5 BB	2
dd233717	3	BEGIN {
a817e89d	4	chdir 't' if -d 't';
dd233717 FC	5	@INC = '../lib';
	6	require q(./test.pl);
	7	}
0b1b7115 JH	8
	9	use strict;
	10	use warnings;
	11
3df5c4b5	12	plan(tests => 61);
e1a479c5	13
b2685f0c NC	14	require mro;
b2685f0c NC	15
e1a479c5 BB	16	{
	17	package MRO_A;
	18	our @ISA = qw//;
	19	package MRO_B;
	20	our @ISA = qw//;
	21	package MRO_C;
	22	our @ISA = qw//;
	23	package MRO_D;
	24	our @ISA = qw/MRO_A MRO_B MRO_C/;
	25	package MRO_E;
	26	our @ISA = qw/MRO_A MRO_B MRO_C/;
	27	package MRO_F;
	28	our @ISA = qw/MRO_D MRO_E/;
	29	}
	30
84dccb35 NC	31	my @MFO_F_DFS = qw/MRO_F MRO_D MRO_A MRO_B MRO_C MRO_E/;
84dccb35 NC	32	my @MFO_F_C3 = qw/MRO_F MRO_D MRO_E MRO_A MRO_B MRO_C/;
e1a479c5	33	is(mro::get_mro('MRO_F'), 'dfs');
c94dd5be	34	ok(eq_array(
84dccb35	35	mro::get_linear_isa('MRO_F'), \@MFO_F_DFS
c94dd5be	36	));
84dccb35 NC	37
	38	ok(eq_array(mro::get_linear_isa('MRO_F', 'dfs'), \@MFO_F_DFS));
	39	ok(eq_array(mro::get_linear_isa('MRO_F', 'c3'), \@MFO_F_C3));
	40	eval{mro::get_linear_isa('MRO_F', 'C3')};
	41	like($@, qr/^Invalid mro name: 'C3'/);
	42
e1a479c5 BB	43	mro::set_mro('MRO_F', 'c3');
e1a479c5 BB	44	is(mro::get_mro('MRO_F'), 'c3');
c94dd5be	45	ok(eq_array(
84dccb35	46	mro::get_linear_isa('MRO_F'), \@MFO_F_C3
c94dd5be	47	));
e1a479c5	48
84dccb35 NC	49	ok(eq_array(mro::get_linear_isa('MRO_F', 'dfs'), \@MFO_F_DFS));
	50	ok(eq_array(mro::get_linear_isa('MRO_F', 'c3'), \@MFO_F_C3));
	51	eval{mro::get_linear_isa('MRO_F', 'C3')};
	52	like($@, qr/^Invalid mro name: 'C3'/);
	53
70cd14a1	54	my @isarev = sort { $a cmp $b } @{mro::get_isarev('MRO_B')};
c94dd5be RGS	55	ok(eq_array(
c94dd5be RGS	56	\@isarev,
e1a479c5	57	[qw/MRO_D MRO_E MRO_F/]
c94dd5be	58	));
e1a479c5 BB	59
	60	ok(!mro::is_universal('MRO_B'));
	61
	62	@UNIVERSAL::ISA = qw/MRO_F/;
	63	ok(mro::is_universal('MRO_B'));
	64
	65	@UNIVERSAL::ISA = ();
80ebaca2	66	ok(!mro::is_universal('MRO_B'));
70cd14a1 CB	67
70cd14a1 CB	68	# is_universal, get_mro, and get_linear_isa should
93f09d7b	69	# handle non-existent packages sanely
70cd14a1 CB	70	ok(!mro::is_universal('Does_Not_Exist'));
	71	is(mro::get_mro('Also_Does_Not_Exist'), 'dfs');
	72	ok(eq_array(
	73	mro::get_linear_isa('Does_Not_Exist_Three'),
	74	[qw/Does_Not_Exist_Three/]
	75	));
	76
	77	# Assigning @ISA via globref
	78	{
	79	package MRO_TestBase;
	80	sub testfunc { return 123 }
	81	package MRO_TestOtherBase;
	82	sub testfunctwo { return 321 }
	83	package MRO_M; our @ISA = qw/MRO_TestBase/;
	84	}
	85	MRO_N::ISA = MRO_M::ISA;
	86	is(eval { MRO_N->testfunc() }, 123);
	87
	88	# XXX TODO (when there's a way to backtrack through a glob's aliases)
	89	# push(@MRO_M::ISA, 'MRO_TestOtherBase');
	90	# is(eval { MRO_N->testfunctwo() }, 321);
9b439311 BB	91
	92	# Simple DESTROY Baseline
	93	{
	94	my $x = 0;
	95	my $obj;
	96
	97	{
	98	package DESTROY_MRO_Baseline;
	99	sub new { bless {} => shift }
	100	sub DESTROY { $x++ }
	101
	102	package DESTROY_MRO_Baseline_Child;
	103	our @ISA = qw/DESTROY_MRO_Baseline/;
	104	}
	105
	106	$obj = DESTROY_MRO_Baseline->new();
	107	undef $obj;
	108	is($x, 1);
	109
	110	$obj = DESTROY_MRO_Baseline_Child->new();
	111	undef $obj;
	112	is($x, 2);
	113	}
	114
	115	# Dynamic DESTROY
	116	{
	117	my $x = 0;
	118	my $obj;
	119
	120	{
	121	package DESTROY_MRO_Dynamic;
	122	sub new { bless {} => shift }
	123
	124	package DESTROY_MRO_Dynamic_Child;
	125	our @ISA = qw/DESTROY_MRO_Dynamic/;
	126	}
	127
	128	$obj = DESTROY_MRO_Dynamic->new();
	129	undef $obj;
	130	is($x, 0);
	131
	132	$obj = DESTROY_MRO_Dynamic_Child->new();
	133	undef $obj;
	134	is($x, 0);
	135
	136	no warnings 'once';
	137	*DESTROY_MRO_Dynamic::DESTROY = sub { $x++ };
	138
	139	$obj = DESTROY_MRO_Dynamic->new();
	140	undef $obj;
	141	is($x, 1);
	142
	143	$obj = DESTROY_MRO_Dynamic_Child->new();
	144	undef $obj;
	145	is($x, 2);
	146	}
22717f83 BB	147
22717f83 BB	148	# clearing @ISA in different ways
5be5c7a6 BB	149	# some are destructive to the package, hence the new
5be5c7a6 BB	150	# package name each time
22717f83 BB	151	{
	152	no warnings 'uninitialized';
	153	{
	154	package ISACLEAR;
	155	our @ISA = qw/XX YY ZZ/;
	156	}
	157	# baseline
	158	ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR XX YY ZZ/]));
	159
	160	# this looks dumb, but it preserves existing behavior for compatibility
	161	# (undefined @ISA elements treated as "main")
	162	$ISACLEAR::ISA[1] = undef;
	163	ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR XX main ZZ/]));
	164
5be5c7a6	165	# undef the array itself
22717f83 BB	166	undef @ISACLEAR::ISA;
22717f83 BB	167	ok(eq_array(mro::get_linear_isa('ISACLEAR'),[qw/ISACLEAR/]));
915d8d75 RD	168
	169	# Now, clear more than one package's @ISA at once
	170	{
	171	package ISACLEAR1;
	172	our @ISA = qw/WW XX/;
	173
	174	package ISACLEAR2;
	175	our @ISA = qw/YY ZZ/;
	176	}
	177	# baseline
	178	ok(eq_array(mro::get_linear_isa('ISACLEAR1'),[qw/ISACLEAR1 WW XX/]));
	179	ok(eq_array(mro::get_linear_isa('ISACLEAR2'),[qw/ISACLEAR2 YY ZZ/]));
	180	(@ISACLEAR1::ISA, @ISACLEAR2::ISA) = ();
	181
934dcd01	182	ok(eq_array(mro::get_linear_isa('ISACLEAR1'),[qw/ISACLEAR1/]));
915d8d75	183	ok(eq_array(mro::get_linear_isa('ISACLEAR2'),[qw/ISACLEAR2/]));
52b45067 RD	184
	185	# [perl #49564] This is a pretty obscure way of clearing @ISA but
	186	# it tests a regression that affects XS code calling av_clear too.
	187	{
	188	package ISACLEAR3;
	189	our @ISA = qw/WW XX/;
	190	}
	191	ok(eq_array(mro::get_linear_isa('ISACLEAR3'),[qw/ISACLEAR3 WW XX/]));
	192	{
	193	package ISACLEAR3;
	194	reset 'I';
	195	}
	196	ok(eq_array(mro::get_linear_isa('ISACLEAR3'),[qw/ISACLEAR3/]));
915d8d75 RD	197	}
	198
	199	# Check that recursion bails out "cleanly" in a variety of cases
	200	# (as opposed to say, bombing the interpreter or something)
	201	{
	202	my @recurse_codes = (
	203	'@MRO_R1::ISA = "MRO_R2"; @MRO_R2::ISA = "MRO_R1";',
	204	'@MRO_R3::ISA = "MRO_R4"; push(@MRO_R4::ISA, "MRO_R3");',
	205	'@MRO_R5::ISA = "MRO_R6"; @MRO_R6::ISA = qw/XX MRO_R5 YY/;',
	206	'@MRO_R7::ISA = "MRO_R8"; push(@MRO_R8::ISA, qw/XX MRO_R7 YY/)',
	207	);
	208	foreach my $code (@recurse_codes) {
	209	eval $code;
	210	ok($@ =~ /Recursive inheritance detected/);
	211	}
22717f83	212	}
915d8d75	213
2e7640f0 BB	214	# Check that SUPER caches get invalidated correctly
	215	{
	216	{
	217	package SUPERTEST;
	218	sub new { bless {} => shift }
	219	sub foo { $_[1]+1 }
	220
	221	package SUPERTEST::MID;
	222	our @ISA = 'SUPERTEST';
	223
	224	package SUPERTEST::KID;
	225	our @ISA = 'SUPERTEST::MID';
	226	sub foo { my $s = shift; $s->SUPER::foo(@_) }
	227
	228	package SUPERTEST::REBASE;
	229	sub foo { $_[1]+3 }
	230	}
	231
	232	my $stk_obj = SUPERTEST::KID->new();
	233	is($stk_obj->foo(1), 2);
	234	{ no warnings 'redefine';
	235	*SUPERTEST::foo = sub { $_[1]+2 };
	236	}
	237	is($stk_obj->foo(2), 4);
	238	@SUPERTEST::MID::ISA = 'SUPERTEST::REBASE';
	239	is($stk_obj->foo(3), 6);
	240	}
	241
26d68d86 TC	242	{
	243	{
	244	# assigning @ISA via arrayref to globref RT 60220
	245	package P1;
	246	sub new { bless {}, shift }
	247
	248	package P2;
	249	}
	250	*{P2::ISA} = [ 'P1' ];
	251	my $foo = P2->new;
	252	ok(!eval { $foo->bark }, "no bark method");
	253	no warnings 'once'; # otherwise it'll bark about P1::bark used only once
	254	*{P1::bark} = sub { "[bark]" };
	255	is(scalar eval { $foo->bark }, "[bark]", "can bark now");
	256	}
4283ec8b B	257
4283ec8b B	258	{
d851b122 TC	259	# assigning @ISA via arrayref then modifying it RT 72866
	260	{
	261	package Q1;
	262	sub foo { }
	263
	264	package Q2;
	265	sub bar { }
	266
	267	package Q3;
	268	}
	269	push @Q3::ISA, "Q1";
	270	can_ok("Q3", "foo");
	271	*Q3::ISA = [];
	272	push @Q3::ISA, "Q1";
	273	can_ok("Q3", "foo");
	274	*Q3::ISA = [];
	275	push @Q3::ISA, "Q2";
	276	can_ok("Q3", "bar");
	277	ok(!Q3->can("foo"), "can't call foo method any longer");
	278	}
	279
	280	{
4283ec8b B	281	# test mro::method_changed_in
	282	my $count = mro::get_pkg_gen("MRO_A");
	283	mro::method_changed_in("MRO_A");
	284	my $count_new = mro::get_pkg_gen("MRO_A");
	285
	286	is($count_new, $count + 1);
	287	}
	288
	289	{
	290	# test if we can call mro::invalidate_all_method_caches;
	291	eval {
	292	mro::invalidate_all_method_caches();
	293	};
	294	is($@, "");
	295	}
44428a46 FC	296
	297	{
	298	# @main::ISA
	299	no warnings 'once';
	300	@main::ISA = 'parent';
	301	my $output = '';
	302	*parent::do = sub { $output .= 'parent' };
	303	*parent2::do = sub { $output .= 'parent2' };
	304	main->do;
	305	@main::ISA = 'parent2';
	306	main->do;
	307	is $output, 'parentparent2', '@main::ISA is magical';
	308	}
af16de9f FC	309
	310	{
	311	# Undefining *ISA, then modifying @ISA
	312	# This broke Class::Trait. See [perl #79024].
	313	{package Class::Trait::Base}
	314	no strict 'refs';
	315	undef *{"Extra::TSpouse::ISA"};
	316	'Extra::TSpouse'->isa('Class::Trait::Base'); # cache the mro
	317	unshift @{"Extra::TSpouse::ISA"}, 'Class::Trait::Base';
	318	ok 'Extra::TSpouse'->isa('Class::Trait::Base'),
	319	'a isa b after undef *a::ISA and @a::ISA modification';
	320	}
f3d2f32d FC	321
	322	{
	323	# Deleting $package::{ISA}
	324	# Broken in 5.10.0; fixed in 5.13.7
	325	@Blength::ISA = 'Bladd';
	326	delete $Blength::{ISA};
	327	ok !Blength->isa("Bladd"), 'delete $package::{ISA}';
	328	}
b9e30492 FC	329
	330	{
	331	# Undefining stashes
	332	@Thrext::ISA = "Thwit";
	333	@Thwit::ISA = "Sile";
	334	undef %Thwit::;
	335	ok !Thrext->isa('Sile'), 'undef %package:: updates subclasses';
	336	}
dfedf892 FC	337
	338	{
	339	# Obliterating @ISA via glob assignment
	340	# Broken in 5.14.0; fixed in 5.17.2
	341	@Gwythaint::ISA = "Fantastic::Creature";
	342	undef *This_glob_haD_better_not_exist; # paranoia; must have no array
	343	Gwythaint::ISA = This_glob_haD_better_not_exist;
	344	ok !Gwythaint->isa("Fantastic::Creature"),
	345	'obliterating @ISA via glob assignment';
	346	}
986d39ee FC	347
	348	{
	349	# Autovivifying @ISA via @{*ISA}
40099ff6	350	no warnings;
986d39ee FC	351	undef *fednu::ISA;
	352	@{*fednu::ISA} = "pyfg";
	353	ok +fednu->isa("pyfg"), 'autovivifying @ISA via *{@ISA}';
	354	}
959f7ad7 FC	355
	356	{
	357	sub Detached::method;
	358	my $h = delete $::{"Detached::"};
	359	eval { local *Detached::method };
	360	is $@, "", 'localising gv-with-cv belonging to detached package';
	361	}
3d460042 FC	362
	363	{
	364	# *ISA localisation
	365	@il::ISA = "ilsuper";
	366	sub ilsuper::can { "puree" }
	367	sub il::tomatoes;
	368	{
	369	local *il::ISA;
	370	is +il->can("tomatoes"), \&il::tomatoes, 'local *ISA';
	371	}
	372	is "il"->can("tomatoes"), "puree", 'local *ISA unwinding';
	373	{
	374	local *il::ISA = [];
	375	is +il->can("tomatoes"), \&il::tomatoes, 'local *ISA = []';
	376	}
	377	is "il"->can("tomatoes"), "puree", 'local *ISA=[] unwinding';
	378	}
c716b3be FC	379
	380	# Changes to UNIVERSAL::DESTROY should not leave stale DESTROY caches
	381	# (part of #114864)
	382	our $destroy_output;
	383	sub UNIVERSAL::DESTROY { $destroy_output = "old" }
	384	my $x = bless[];
	385	undef $x; # cache the DESTROY method
	386	undef *UNIVERSAL::DESTROY;
	387	*UNIVERSAL::DESTROY = sub { $destroy_output = "new" };
	388	$x = bless[];
	389	undef $x; # should use the new DESTROY
	390	is $destroy_output, "new",
	391	'Changes to UNIVERSAL::DESTROY invalidate DESTROY caches';
	392	undef *UNIVERSAL::DESTROY;
3df5c4b5 FC	393
	394	{
	395	no warnings 'uninitialized';
	396	$#_119433::ISA++;
	397	pass "no crash when ISA contains nonexistent elements";
	398	}