X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=t%2Fop%2Fsort.t;h=bdb48856b945c6bda48bfb028998bc53a1cfabd5;hb=bd7d4f4d586a396d1b104a293cce339c8d63ce5a;hp=f7bba3d263d9bfbf9dc48d7d995a1f48622116d2;hpb=e507f0504293808d931970586c0530e4bb738a80;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/t/op/sort.t b/t/op/sort.t
index f7bba3d..bdb4885 100755
--- a/t/op/sort.t
+++ b/t/op/sort.t
@@ -2,19 +2,27 @@
 
 BEGIN {
     chdir 't' if -d 't';
-    unshift @INC, '../lib';
+    @INC = '../lib';
 }
-print "1..38\n";
+use warnings;
+print "1..129\n";
 
-# XXX known to leak scalars
-$ENV{PERL_DESTRUCT_LEVEL} = 0 unless $ENV{PERL_DESTRUCT_LEVEL} > 3;
+# these shouldn't hang
+{
+    no warnings;
+    sort { for ($_ = 0;; $_++) {} } @a;
+    sort { while(1) {}            } @a;
+    sort { while(1) { last; }     } @a;
+    sort { while(0) { last; }     } @a;
+}
 
-sub backwards { $a lt $b ? 1 : $a gt $b ? -1 : 0 }
+sub Backwards { $a lt $b ? 1 : $a gt $b ? -1 : 0 }
+sub Backwards_stacked($$) { my($a,$b) = @_; $a lt $b ? 1 : $a gt $b ? -1 : 0 }
 
 my $upperfirst = 'A' lt 'a';
 
 # Beware: in future this may become hairier because of possible
-# collation complications: qw(A a B c) can be sorted at least as
+# collation complications: qw(A a B b) can be sorted at least as
 # any of the following
 #
 #	A a B b
@@ -35,171 +43,630 @@ $expected = $upperfirst ? 'AbelCaincatdogx' : 'catdogxAbelCain';
 print "# 1: x = '$x', expected = '$expected'\n";
 print ($x eq $expected ? "ok 1\n" : "not ok 1\n");
 
-$x = join('', sort( backwards @harry));
+$x = join('', sort( Backwards @harry));
 $expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
 print "# 2: x = '$x', expected = '$expected'\n";
 print ($x eq $expected ? "ok 2\n" : "not ok 2\n");
 
+$x = join('', sort( Backwards_stacked @harry));
+$expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
+print "# 3: x = '$x', expected = '$expected'\n";
+print ($x eq $expected ? "ok 3\n" : "not ok 3\n");
+
 $x = join('', sort @george, 'to', @harry);
 $expected = $upperfirst ?
     'AbelAxedCaincatchaseddoggonepunishedtoxyz' :
     'catchaseddoggonepunishedtoxyzAbelAxedCain' ;
-print "# 3: x = '$x', expected = '$expected'\n";
-print ($x eq $expected ?"ok 3\n":"not ok 3\n");
+print "# 4: x = '$x', expected = '$expected'\n";
+print ($x eq $expected ?"ok 4\n":"not ok 4\n");
 
 @a = ();
 @b = reverse @a;
-print ("@b" eq "" ? "ok 4\n" : "not ok 4 (@b)\n");
+print ("@b" eq "" ? "ok 5\n" : "not ok 5 (@b)\n");
 
 @a = (1);
 @b = reverse @a;
-print ("@b" eq "1" ? "ok 5\n" : "not ok 5 (@b)\n");
+print ("@b" eq "1" ? "ok 6\n" : "not ok 6 (@b)\n");
 
 @a = (1,2);
 @b = reverse @a;
-print ("@b" eq "2 1" ? "ok 6\n" : "not ok 6 (@b)\n");
+print ("@b" eq "2 1" ? "ok 7\n" : "not ok 7 (@b)\n");
 
 @a = (1,2,3);
 @b = reverse @a;
-print ("@b" eq "3 2 1" ? "ok 7\n" : "not ok 7 (@b)\n");
+print ("@b" eq "3 2 1" ? "ok 8\n" : "not ok 8 (@b)\n");
 
 @a = (1,2,3,4);
 @b = reverse @a;
-print ("@b" eq "4 3 2 1" ? "ok 8\n" : "not ok 8 (@b)\n");
+print ("@b" eq "4 3 2 1" ? "ok 9\n" : "not ok 9 (@b)\n");
 
 @a = (10,2,3,4);
 @b = sort {$a <=> $b;} @a;
-print ("@b" eq "2 3 4 10" ? "ok 9\n" : "not ok 9 (@b)\n");
+print ("@b" eq "2 3 4 10" ? "ok 10\n" : "not ok 10 (@b)\n");
 
-$sub = 'backwards';
+$sub = 'Backwards';
 $x = join('', sort $sub @harry);
 $expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
-print "# 10: x = $x, expected = '$expected'\n";
-print ($x eq $expected ? "ok 10\n" : "not ok 10\n");
+print "# 11: x = $x, expected = '$expected'\n";
+print ($x eq $expected ? "ok 11\n" : "not ok 11\n");
+
+$sub = 'Backwards_stacked';
+$x = join('', sort $sub @harry);
+$expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
+print "# 12: x = $x, expected = '$expected'\n";
+print ($x eq $expected ? "ok 12\n" : "not ok 12\n");
 
 # literals, combinations
 
 @b = sort (4,1,3,2);
-print ("@b" eq '1 2 3 4' ? "ok 11\n" : "not ok 11\n");
+print ("@b" eq '1 2 3 4' ? "ok 13\n" : "not ok 13\n");
 print "# x = '@b'\n";
 
 @b = sort grep { $_ } (4,1,3,2);
-print ("@b" eq '1 2 3 4' ? "ok 12\n" : "not ok 12\n");
+print ("@b" eq '1 2 3 4' ? "ok 14\n" : "not ok 14\n");
 print "# x = '@b'\n";
 
 @b = sort map { $_ } (4,1,3,2);
-print ("@b" eq '1 2 3 4' ? "ok 13\n" : "not ok 13\n");
+print ("@b" eq '1 2 3 4' ? "ok 15\n" : "not ok 15\n");
 print "# x = '@b'\n";
 
 @b = sort reverse (4,1,3,2);
-print ("@b" eq '1 2 3 4' ? "ok 14\n" : "not ok 14\n");
+print ("@b" eq '1 2 3 4' ? "ok 16\n" : "not ok 16\n");
 print "# x = '@b'\n";
 
-$^W = 0;
 # redefining sort sub inside the sort sub should fail
 sub twoface { *twoface = sub { $a <=> $b }; &twoface }
 eval { @b = sort twoface 4,1,3,2 };
-print ($@ =~ /redefine active sort/ ? "ok 15\n" : "not ok 15\n");
+print ($@ =~ /redefine active sort/ ? "ok 17\n" : "not ok 17\n");
 
 # redefining sort subs outside the sort should not fail
-eval { *twoface = sub { &backwards } };
-print $@ ? "not ok 16\n" : "ok 16\n";
+eval { no warnings 'redefine'; *twoface = sub { &Backwards } };
+print $@ ? "not ok 18\n" : "ok 18\n";
 
 eval { @b = sort twoface 4,1,3,2 };
-print ("@b" eq '4 3 2 1' ? "ok 17\n" : "not ok 17 |@b|\n");
+print ("@b" eq '4 3 2 1' ? "ok 19\n" : "not ok 19 |@b|\n");
 
-*twoface = sub { *twoface = *backwards; $a <=> $b };
+{
+  no warnings 'redefine';
+  *twoface = sub { *twoface = *Backwards; $a <=> $b };
+}
 eval { @b = sort twoface 4,1 };
-print ($@ =~ /redefine active sort/ ? "ok 18\n" : "not ok 18\n");
+print ($@ =~ /redefine active sort/ ? "ok 20\n" : "not ok 20\n");
 
-*twoface = sub {
+{
+  no warnings 'redefine';
+  *twoface = sub {
                  eval 'sub twoface { $a <=> $b }';
-		 die($@ =~ /redefine active sort/ ? "ok 19\n" : "not ok 19\n");
+		 die($@ =~ /redefine active sort/ ? "ok 21\n" : "not ok 21\n");
 		 $a <=> $b;
 	       };
+}
 eval { @b = sort twoface 4,1 };
-print $@ ? "$@" : "not ok 19\n";
+print $@ ? "$@" : "not ok 21\n";
 
 eval <<'CODE';
-    my @result = sort main'backwards 'one', 'two';
+    my @result = sort main'Backwards 'one', 'two';
 CODE
-print $@ ? "not ok 20\n# $@" : "ok 20\n";
+print $@ ? "not ok 22\n# $@" : "ok 22\n";
 
 eval <<'CODE';
     # "sort 'one', 'two'" should not try to parse "'one" as a sort sub
     my @result = sort 'one', 'two';
 CODE
-print $@ ? "not ok 21\n# $@" : "ok 21\n";
+print $@ ? "not ok 23\n# $@" : "ok 23\n";
 
 {
-  my $sortsub = \&backwards;
-  my $sortglob = *backwards;
-  my $sortglobr = \*backwards;
-  my $sortname = 'backwards';
+  my $sortsub = \&Backwards;
+  my $sortglob = *Backwards;
+  my $sortglobr = \*Backwards;
+  my $sortname = 'Backwards';
   @b = sort $sortsub 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 22\n" : "not ok 22 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 24\n" : "not ok 24 |@b|\n");
   @b = sort $sortglob 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 23\n" : "not ok 23 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 25\n" : "not ok 25 |@b|\n");
   @b = sort $sortname 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 24\n" : "not ok 24 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 26\n" : "not ok 26 |@b|\n");
   @b = sort $sortglobr 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 25\n" : "not ok 25 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 27\n" : "not ok 27 |@b|\n");
 }
 
 {
-  local $sortsub = \&backwards;
-  local $sortglob = *backwards;
-  local $sortglobr = \*backwards;
-  local $sortname = 'backwards';
+  my $sortsub = \&Backwards_stacked;
+  my $sortglob = *Backwards_stacked;
+  my $sortglobr = \*Backwards_stacked;
+  my $sortname = 'Backwards_stacked';
   @b = sort $sortsub 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 26\n" : "not ok 26 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 28\n" : "not ok 28 |@b|\n");
   @b = sort $sortglob 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 27\n" : "not ok 27 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 29\n" : "not ok 29 |@b|\n");
   @b = sort $sortname 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 28\n" : "not ok 28 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 30\n" : "not ok 30 |@b|\n");
   @b = sort $sortglobr 4,1,3,2;
-  print ("@b" eq '4 3 2 1' ? "ok 29\n" : "not ok 29 |@b|\n");
+  print ("@b" eq '4 3 2 1' ? "ok 31\n" : "not ok 31 |@b|\n");
+}
+
+{
+  local $sortsub = \&Backwards;
+  local $sortglob = *Backwards;
+  local $sortglobr = \*Backwards;
+  local $sortname = 'Backwards';
+  @b = sort $sortsub 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 32\n" : "not ok 32 |@b|\n");
+  @b = sort $sortglob 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 33\n" : "not ok 33 |@b|\n");
+  @b = sort $sortname 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 34\n" : "not ok 34 |@b|\n");
+  @b = sort $sortglobr 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 35\n" : "not ok 35 |@b|\n");
+}
+
+{
+  local $sortsub = \&Backwards_stacked;
+  local $sortglob = *Backwards_stacked;
+  local $sortglobr = \*Backwards_stacked;
+  local $sortname = 'Backwards_stacked';
+  @b = sort $sortsub 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 36\n" : "not ok 36 |@b|\n");
+  @b = sort $sortglob 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 37\n" : "not ok 37 |@b|\n");
+  @b = sort $sortname 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 38\n" : "not ok 38 |@b|\n");
+  @b = sort $sortglobr 4,1,3,2;
+  print ("@b" eq '4 3 2 1' ? "ok 39\n" : "not ok 39 |@b|\n");
 }
 
 ## exercise sort builtins... ($a <=> $b already tested)
 @a = ( 5, 19, 1996, 255, 90 );
-@b = sort { $b <=> $a } @a;
-print ("@b" eq '1996 255 90 19 5' ? "ok 30\n" : "not ok 30\n");
+@b = sort {
+    my $dummy;		# force blockness
+    return $b <=> $a
+} @a;
+print ("@b" eq '1996 255 90 19 5' ? "ok 40\n" : "not ok 40\n");
 print "# x = '@b'\n";
 $x = join('', sort { $a cmp $b } @harry);
 $expected = $upperfirst ? 'AbelCaincatdogx' : 'catdogxAbelCain';
-print ($x eq $expected ? "ok 31\n" : "not ok 31\n");
+print ($x eq $expected ? "ok 41\n" : "not ok 41\n");
 print "# x = '$x'; expected = '$expected'\n";
 $x = join('', sort { $b cmp $a } @harry);
 $expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
-print ($x eq $expected ? "ok 32\n" : "not ok 32\n");
+print ($x eq $expected ? "ok 42\n" : "not ok 42\n");
 print "# x = '$x'; expected = '$expected'\n";
 {
     use integer;
     @b = sort { $a <=> $b } @a;
-    print ("@b" eq '5 19 90 255 1996' ? "ok 33\n" : "not ok 33\n");
+    print ("@b" eq '5 19 90 255 1996' ? "ok 43\n" : "not ok 43\n");
     print "# x = '@b'\n";
     @b = sort { $b <=> $a } @a;
-    print ("@b" eq '1996 255 90 19 5' ? "ok 34\n" : "not ok 34\n");
+    print ("@b" eq '1996 255 90 19 5' ? "ok 44\n" : "not ok 44\n");
     print "# x = '@b'\n";
     $x = join('', sort { $a cmp $b } @harry);
     $expected = $upperfirst ? 'AbelCaincatdogx' : 'catdogxAbelCain';
-    print ($x eq $expected ? "ok 35\n" : "not ok 35\n");
+    print ($x eq $expected ? "ok 45\n" : "not ok 45\n");
     print "# x = '$x'; expected = '$expected'\n";
     $x = join('', sort { $b cmp $a } @harry);
     $expected = $upperfirst ? 'xdogcatCainAbel' : 'CainAbelxdogcat';
-    print ($x eq $expected ? "ok 36\n" : "not ok 36\n");
+    print ($x eq $expected ? "ok 46\n" : "not ok 46\n");
     print "# x = '$x'; expected = '$expected'\n";
 }
 
 # test that an optimized-away comparison block doesn't take any other
 # arguments away with it
 $x = join('', sort { $a <=> $b } 3, 1, 2);
-print $x eq "123" ? "ok 37\n" : "not ok 37\n";
+print $x eq "123" ? "ok 47\n" : "not ok 47\n";
 
 # test sorting in non-main package
 package Foo;
 @a = ( 5, 19, 1996, 255, 90 );
 @b = sort { $b <=> $a } @a;
-print ("@b" eq '1996 255 90 19 5' ? "ok 38\n" : "not ok 38\n");
+print ("@b" eq '1996 255 90 19 5' ? "ok 48\n" : "not ok 48\n");
+print "# x = '@b'\n";
+
+@b = sort main::Backwards_stacked @a;
+print ("@b" eq '90 5 255 1996 19' ? "ok 49\n" : "not ok 49\n");
 print "# x = '@b'\n";
+
+# check if context for sort arguments is handled right
+
+$test = 49;
+sub test_if_list {
+    my $gimme = wantarray;
+    print "not " unless $gimme;
+    ++$test;
+    print "ok $test\n";
+}
+my $m = sub { $a <=> $b };
+
+sub cxt_one { sort $m test_if_list() }
+cxt_one();
+sub cxt_two { sort { $a <=> $b } test_if_list() }
+cxt_two();
+sub cxt_three { sort &test_if_list() }
+cxt_three();
+
+sub test_if_scalar {
+    my $gimme = wantarray;
+    print "not " if $gimme or !defined($gimme);
+    ++$test;
+    print "ok $test\n";
+}
+
+$m = \&test_if_scalar;
+sub cxt_four { sort $m 1,2 }
+@x = cxt_four();
+sub cxt_five { sort { test_if_scalar($a,$b); } 1,2 }
+@x = cxt_five();
+sub cxt_six { sort test_if_scalar 1,2 }
+@x = cxt_six();
+
+# test against a reentrancy bug
+{
+    package Bar;
+    sub compare { $a cmp $b }
+    sub reenter { my @force = sort compare qw/a b/ }
+}
+{
+    my($def, $init) = (0, 0);
+    @b = sort {
+	$def = 1 if defined $Bar::a;
+	Bar::reenter() unless $init++;
+	$a <=> $b
+    } qw/4 3 1 2/;
+    print ("@b" eq '1 2 3 4' ? "ok 56\n" : "not ok 56\n");
+    print "# x = '@b'\n";
+    print !$def ? "ok 57\n" : "not ok 57\n";
+}
+
+# Bug 19991001.003
+{
+    sub routine { "one", "two" };
+    @a = sort(routine(1));
+    print "@a" eq "one two" ? "ok 58\n" : "not ok 58\n";
+}
+
+
+my $test = 59;
+sub ok {
+    print "not " unless $_[0] eq $_[1];
+    print "ok $test - $_[2]\n";
+    print "#[$_[0]] ne [$_[1]]\n" unless $_[0] eq $_[1];
+    $test++;
+}
+
+# check for in-place optimisation of @a = sort @a
+{
+    my ($r1,$r2,@a);
+    our @g;
+    @g = (3,2,1); $r1 = \$g[2]; @g = sort @g; $r2 = \$g[0];
+    ok "$r1-@g", "$r2-1 2 3", "inplace sort of global";
+
+    @a = qw(b a c); $r1 = \$a[1]; @a = sort @a; $r2 = \$a[0];
+    ok "$r1-@a", "$r2-a b c", "inplace sort of lexical";
+
+    @g = (2,3,1); $r1 = \$g[1]; @g = sort { $b <=> $a } @g; $r2 = \$g[0];
+    ok "$r1-@g", "$r2-3 2 1", "inplace reversed sort of global";
+
+    @g = (2,3,1);
+    $r1 = \$g[1]; @g = sort { $a<$b?1:$a>$b?-1:0 } @g; $r2 = \$g[0];
+    ok "$r1-@g", "$r2-3 2 1", "inplace custom sort of global";
+
+    sub mysort { $b cmp $a };
+    @a = qw(b c a); $r1 = \$a[1]; @a = sort mysort @a; $r2 = \$a[0];
+    ok "$r1-@a", "$r2-c b a", "inplace sort with function of lexical";
+
+    use Tie::Array;
+    my @t;
+    tie @t, 'Tie::StdArray';
+
+    @t = qw(b c a); @t = sort @t;
+    ok "@t", "a b c", "inplace sort of tied array";
+
+    @t = qw(b c a); @t = sort mysort @t;
+    ok "@t", "c b a", "inplace sort of tied array with function";
+
+    #  [perl #29790] don't optimise @a = ('a', sort @a) !
+
+    @g = (3,2,1); @g = ('0', sort @g);
+    ok "@g", "0 1 2 3", "un-inplace sort of global";
+    @g = (3,2,1); @g = (sort(@g),'4');
+    ok "@g", "1 2 3 4", "un-inplace sort of global 2";
+
+    @a = qw(b a c); @a = ('x', sort @a);
+    ok "@a", "x a b c", "un-inplace sort of lexical";
+    @a = qw(b a c); @a = ((sort @a), 'x');
+    ok "@a", "a b c x", "un-inplace sort of lexical 2";
+
+    @g = (2,3,1); @g = ('0', sort { $b <=> $a } @g);
+    ok "@g", "0 3 2 1", "un-inplace reversed sort of global";
+    @g = (2,3,1); @g = ((sort { $b <=> $a } @g),'4');
+    ok "@g", "3 2 1 4", "un-inplace reversed sort of global 2";
+
+    @g = (2,3,1); @g = ('0', sort { $a<$b?1:$a>$b?-1:0 } @g);
+    ok "@g", "0 3 2 1", "un-inplace custom sort of global";
+    @g = (2,3,1); @g = ((sort { $a<$b?1:$a>$b?-1:0 } @g),'4');
+    ok "@g", "3 2 1 4", "un-inplace custom sort of global 2";
+
+    @a = qw(b c a); @a = ('x', sort mysort @a);
+    ok "@a", "x c b a", "un-inplace sort with function of lexical";
+    @a = qw(b c a); @a = ((sort mysort @a),'x');
+    ok "@a", "c b a x", "un-inplace sort with function of lexical 2";
+}
+
+# Test optimisations of reversed sorts. As we now guarantee stability by
+# default, # optimisations which do not provide this are bogus.
+
+{
+    package Oscalar;
+    use overload (qw("" stringify 0+ numify fallback 1));
+
+    sub new {
+	bless [$_[1], $_[2]], $_[0];
+    }
+
+    sub stringify { $_[0]->[0] }
+
+    sub numify { $_[0]->[1] }
+}
+
+sub generate {
+    my $count = 0;
+    map {new Oscalar $_, $count++} qw(A A A B B B C C C);
+}
+
+my @input = &generate;
+my @output = sort @input;
+ok join(" ", map {0+$_} @output), "0 1 2 3 4 5 6 7 8", "Simple stable sort";
+
+@input = &generate;
+@input = sort @input;
+ok join(" ", map {0+$_} @input), "0 1 2 3 4 5 6 7 8",
+    "Simple stable in place sort";
+
+# This won't be very interesting
+@input = &generate;
+@output = sort {$a <=> $b} @input;
+ok "@output", "A A A B B B C C C", 'stable $a <=> $b sort';
+
+@input = &generate;
+@output = sort {$a cmp $b} @input;
+ok join(" ", map {0+$_} @output), "0 1 2 3 4 5 6 7 8", 'stable $a cmp $b sort';
+
+@input = &generate;
+@input = sort {$a cmp $b} @input;
+ok join(" ", map {0+$_} @input), "0 1 2 3 4 5 6 7 8",
+    'stable $a cmp $b in place sort';
+
+@input = &generate;
+@output = sort {$b cmp $a} @input;
+ok join(" ", map {0+$_} @output), "6 7 8 3 4 5 0 1 2", 'stable $b cmp $a sort';
+
+@input = &generate;
+@input = sort {$b cmp $a} @input;
+ok join(" ", map {0+$_} @input), "6 7 8 3 4 5 0 1 2",
+    'stable $b cmp $a in place sort';
+
+@input = &generate;
+@output = reverse sort @input;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0", "Reversed stable sort";
+
+@input = &generate;
+@input = reverse sort @input;
+ok join(" ", map {0+$_} @input), "8 7 6 5 4 3 2 1 0",
+    "Reversed stable in place sort";
+
+@input = &generate;
+my $output = reverse sort @input;
+ok $output, "CCCBBBAAA", "Reversed stable sort in scalar context";
+
+
+@input = &generate;
+@output = reverse sort {$a cmp $b} @input;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0",
+    'reversed stable $a cmp $b sort';
+
+@input = &generate;
+@input = reverse sort {$a cmp $b} @input;
+ok join(" ", map {0+$_} @input), "8 7 6 5 4 3 2 1 0",
+    'revesed stable $a cmp $b in place sort';
+
+@input = &generate;
+$output = reverse sort {$a cmp $b} @input;
+ok $output, "CCCBBBAAA", 'Reversed stable $a cmp $b sort in scalar context';
+
+@input = &generate;
+@output = reverse sort {$b cmp $a} @input;
+ok join(" ", map {0+$_} @output), "2 1 0 5 4 3 8 7 6",
+    'reversed stable $b cmp $a sort';
+
+@input = &generate;
+@input = reverse sort {$b cmp $a} @input;
+ok join(" ", map {0+$_} @input), "2 1 0 5 4 3 8 7 6",
+    'revesed stable $b cmp $a in place sort';
+
+@input = &generate;
+$output = reverse sort {$b cmp $a} @input;
+ok $output, "AAABBBCCC", 'Reversed stable $b cmp $a sort in scalar context';
+
+sub stuff {
+    # Something complex enough to defeat any constant folding optimiser
+    $$ - $$;
+}
+
+@input = &generate;
+@output = reverse sort {stuff || $a cmp $b} @input;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0",
+    'reversed stable complex sort';
+
+@input = &generate;
+@input = reverse sort {stuff || $a cmp $b} @input;
+ok join(" ", map {0+$_} @input), "8 7 6 5 4 3 2 1 0",
+    'revesed stable complex in place sort';
+
+@input = &generate;
+$output = reverse sort {stuff || $a cmp $b } @input;
+ok $output, "CCCBBBAAA", 'Reversed stable complex sort in scalar context';
+
+sub sortr {
+    reverse sort @_;
+}
+
+@output = sortr &generate;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0",
+    'reversed stable sort return list context';
+$output = sortr &generate;
+ok $output, "CCCBBBAAA",
+    'reversed stable sort return scalar context';
+
+sub sortcmpr {
+    reverse sort {$a cmp $b} @_;
+}
+
+@output = sortcmpr &generate;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0",
+    'reversed stable $a cmp $b sort return list context';
+$output = sortcmpr &generate;
+ok $output, "CCCBBBAAA",
+    'reversed stable $a cmp $b sort return scalar context';
+
+sub sortcmprba {
+    reverse sort {$b cmp $a} @_;
+}
+
+@output = sortcmprba &generate;
+ok join(" ", map {0+$_} @output), "2 1 0 5 4 3 8 7 6",
+    'reversed stable $b cmp $a sort return list context';
+$output = sortcmprba &generate;
+ok $output, "AAABBBCCC",
+'reversed stable $b cmp $a sort return scalar context';
+
+sub sortcmprq {
+    reverse sort {stuff || $a cmp $b} @_;
+}
+
+@output = sortcmpr &generate;
+ok join(" ", map {0+$_} @output), "8 7 6 5 4 3 2 1 0",
+    'reversed stable complex sort return list context';
+$output = sortcmpr &generate;
+ok $output, "CCCBBBAAA",
+    'reversed stable complex sort return scalar context';
+
+# And now with numbers
+
+sub generate1 {
+    my $count = 'A';
+    map {new Oscalar $count++, $_} 0, 0, 0, 1, 1, 1, 2, 2, 2;
+}
+
+# This won't be very interesting
+@input = &generate1;
+@output = sort {$a cmp $b} @input;
+ok "@output", "A B C D E F G H I", 'stable $a cmp $b sort';
+
+@input = &generate1;
+@output = sort {$a <=> $b} @input;
+ok "@output", "A B C D E F G H I", 'stable $a <=> $b sort';
+
+@input = &generate1;
+@input = sort {$a <=> $b} @input;
+ok "@input", "A B C D E F G H I", 'stable $a <=> $b in place sort';
+
+@input = &generate1;
+@output = sort {$b <=> $a} @input;
+ok "@output", "G H I D E F A B C", 'stable $b <=> $a sort';
+
+@input = &generate1;
+@input = sort {$b <=> $a} @input;
+ok "@input", "G H I D E F A B C", 'stable $b <=> $a in place sort';
+
+# test that optimized {$b cmp $a} and {$b <=> $a} remain stable
+# (new in 5.9) without overloading
+{ no warnings;
+@b = sort { $b <=> $a } @input = qw/5first 6first 5second 6second/;
+ok "@b" , "6first 6second 5first 5second", "optimized {$b <=> $a} without overloading" ;
+@input = sort {$b <=> $a} @input;
+ok "@input" , "6first 6second 5first 5second","inline optimized {$b <=> $a} without overloading" ;
+};
+
+# These two are actually doing string cmp on 0 1 and 2
+@input = &generate1;
+@output = reverse sort @input;
+ok "@output", "I H G F E D C B A", "Reversed stable sort";
+
+@input = &generate1;
+@input = reverse sort @input;
+ok "@input", "I H G F E D C B A", "Reversed stable in place sort";
+
+@input = &generate1;
+$output = reverse sort @input;
+ok $output, "IHGFEDCBA", "Reversed stable sort in scalar context";
+
+@input = &generate1;
+@output = reverse sort {$a <=> $b} @input;
+ok "@output", "I H G F E D C B A", 'reversed stable $a <=> $b sort';
+
+@input = &generate1;
+@input = reverse sort {$a <=> $b} @input;
+ok "@input", "I H G F E D C B A", 'revesed stable $a <=> $b in place sort';
+
+@input = &generate1;
+$output = reverse sort {$a <=> $b} @input;
+ok $output, "IHGFEDCBA", 'reversed stable $a <=> $b sort in scalar context';
+
+@input = &generate1;
+@output = reverse sort {$b <=> $a} @input;
+ok "@output", "C B A F E D I H G", 'reversed stable $b <=> $a sort';
+
+@input = &generate1;
+@input = reverse sort {$b <=> $a} @input;
+ok "@input", "C B A F E D I H G", 'revesed stable $b <=> $a in place sort';
+
+@input = &generate1;
+$output = reverse sort {$b <=> $a} @input;
+ok $output, "CBAFEDIHG", 'reversed stable $b <=> $a sort in scalar context';
+
+@input = &generate1;
+@output = reverse sort {stuff || $a <=> $b} @input;
+ok "@output", "I H G F E D C B A", 'reversed stable complex sort';
+
+@input = &generate1;
+@input = reverse sort {stuff || $a <=> $b} @input;
+ok "@input", "I H G F E D C B A", 'revesed stable complex in place sort';
+
+@input = &generate1;
+$output = reverse sort {stuff || $a <=> $b} @input;
+ok $output, "IHGFEDCBA", 'reversed stable complex sort in scalar context';
+
+sub sortnumr {
+    reverse sort {$a <=> $b} @_;
+}
+
+@output = sortnumr &generate1;
+ok "@output", "I H G F E D C B A",
+    'reversed stable $a <=> $b sort return list context';
+$output = sortnumr &generate1;
+ok $output, "IHGFEDCBA", 'reversed stable $a <=> $b sort return scalar context';
+
+sub sortnumrba {
+    reverse sort {$b <=> $a} @_;
+}
+
+@output = sortnumrba &generate1;
+ok "@output", "C B A F E D I H G",
+    'reversed stable $b <=> $a sort return list context';
+$output = sortnumrba &generate1;
+ok $output, "CBAFEDIHG", 'reversed stable $b <=> $a sort return scalar context';
+
+sub sortnumrq {
+    reverse sort {stuff || $a <=> $b} @_;
+}
+
+@output = sortnumrq &generate1;
+ok "@output", "I H G F E D C B A",
+    'reversed stable complex sort return list context';
+$output = sortnumrq &generate1;
+ok $output, "IHGFEDCBA", 'reversed stable complex sort return scalar context';
+
+@output = reverse (sort(qw(C A B)), 0);
+ok "@output", "0 C B A", 'reversed sort with trailing argument';
+
+@output = reverse (0, sort(qw(C A B)));
+ok "@output", "C B A 0", 'reversed sort with leading argument';