X-Git-Url: https://perl5.git.perl.org/perl5.git/blobdiff_plain/9402d6ed2c283eecb57dee09174d6f259c11dbef..d408447cb636e46fcb4f7fe7d0909bb351b7ba22:/t/op/substr.t

diff --git a/t/op/substr.t b/t/op/substr.t
old mode 100755
new mode 100644
index 85574d5..abd5d7f
--- a/t/op/substr.t
+++ b/t/op/substr.t
@@ -1,7 +1,5 @@
 #!./perl
 
-print "1..174\n";
-
 #P = start of string  Q = start of substr  R = end of substr  S = end of string
 
 BEGIN {
@@ -23,198 +21,199 @@ $SIG{__WARN__} = sub {
      }
 };
 
-sub ok { print (($_[1] ? "" : "not ") . "ok $_[0]\n") }
+BEGIN { require './test.pl'; }
 
-$FATAL_MSG = '^substr outside of string' ;
+plan(382);
 
-ok 1, substr($a,0,3) eq 'abc';   # P=Q R S
-ok 2, substr($a,3,3) eq 'def';   # P Q R S
-ok 3, substr($a,6,999) eq 'xyz'; # P Q S R
-$b = substr($a,999,999) ; # warn # P R Q S
-ok 4, $w-- == 1 ;
-eval{substr($a,999,999) = "" ; };# P R Q S
-ok 5, $@ =~ /$FATAL_MSG/;
-ok 6, substr($a,0,-6) eq 'abc';  # P=Q R S
-ok 7, substr($a,-3,1) eq 'x';    # P Q R S
+run_tests() unless caller;
 
-$[ = 1;
+my $krunch = "a";
 
-ok 8, substr($a,1,3) eq 'abc' ;  # P=Q R S
-ok 9, substr($a,4,3) eq 'def' ;  # P Q R S
-ok 10, substr($a,7,999) eq 'xyz';# P Q S R
-$b = substr($a,999,999) ; # warn # P R Q S
-ok 11, $w-- == 1 ;
-eval{substr($a,999,999) = "" ; } ; # P R Q S
-ok 12, $@ =~ /$FATAL_MSG/;
-ok 13, substr($a,1,-6) eq 'abc' ;# P=Q R S
-ok 14, substr($a,-3,1) eq 'x' ;  # P Q R S
+sub run_tests {
 
-$[ = 0;
+$FATAL_MSG = qr/^substr outside of string/;
+
+is(substr($a,0,3), 'abc');   # P=Q R S
+is(substr($a,3,3), 'def');   # P Q R S
+is(substr($a,6,999), 'xyz'); # P Q S R
+$b = substr($a,999,999) ; # warn # P R Q S
+is ($w--, 1);
+eval{substr($a,999,999) = "" ; };# P R Q S
+like ($@, $FATAL_MSG);
+is(substr($a,0,-6), 'abc');  # P=Q R S
+is(substr($a,-3,1), 'x');    # P Q R S
+sub{$b = shift}->(substr($a,999,999));
+is ($w--, 1, 'boundless lvalue substr only warns on fetch');
 
 substr($a,3,3) = 'XYZ';
-ok 15, $a eq 'abcXYZxyz' ;
+is($a, 'abcXYZxyz' );
 substr($a,0,2) = '';
-ok 16, $a eq 'cXYZxyz' ;
+is($a, 'cXYZxyz' );
 substr($a,0,0) = 'ab';
-ok 17, $a eq 'abcXYZxyz' ;
+is($a, 'abcXYZxyz' );
 substr($a,0,0) = '12345678';
-ok 18, $a eq '12345678abcXYZxyz' ;
+is($a, '12345678abcXYZxyz' );
 substr($a,-3,3) = 'def';
-ok 19, $a eq '12345678abcXYZdef';
+is($a, '12345678abcXYZdef');
 substr($a,-3,3) = '<';
-ok 20, $a eq '12345678abcXYZ<' ;
+is($a, '12345678abcXYZ<' );
 substr($a,-1,1) = '12345678';
-ok 21, $a eq '12345678abcXYZ12345678' ;
+is($a, '12345678abcXYZ12345678' );
 
 $a = 'abcdefxyz';
 
-ok 22, substr($a,6) eq 'xyz' ;        # P Q R=S
-ok 23, substr($a,-3) eq 'xyz' ;       # P Q R=S
+is(substr($a,6), 'xyz' );        # P Q R=S
+is(substr($a,-3), 'xyz' );       # P Q R=S
 $b = substr($a,999,999) ; # warning   # P R=S Q
-ok 24, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,999,999) = "" ; } ;    # P R=S Q
-ok 25, $@ =~ /$FATAL_MSG/;
-ok 26, substr($a,0) eq 'abcdefxyz' ;  # P=Q R=S
-ok 27, substr($a,9) eq '' ;           # P Q=R=S
-ok 28, substr($a,-11) eq 'abcdefxyz'; # Q P R=S
-ok 29, substr($a,-9) eq 'abcdefxyz';  # P=Q R=S
+like($@, $FATAL_MSG);
+is(substr($a,0), 'abcdefxyz');  # P=Q R=S
+is(substr($a,9), '');           # P Q=R=S
+is(substr($a,-11), 'abcdefxyz'); # Q P R=S
+is(substr($a,-9), 'abcdefxyz');  # P=Q R=S
 
 $a = '54321';
 
 $b = substr($a,-7, 1) ; # warn  # Q R P S
-ok 30, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-7, 1) = "" ; }; # Q R P S
-ok 31, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 $b = substr($a,-7,-6) ; # warn  # Q R P S
-ok 32, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-7,-6) = "" ; }; # Q R P S
-ok 33, $@ =~ /$FATAL_MSG/;
-ok 34, substr($a,-5,-7) eq '';  # R P=Q S
-ok 35, substr($a, 2,-7) eq '';  # R P Q S
-ok 36, substr($a,-3,-7) eq '';  # R P Q S
-ok 37, substr($a, 2,-5) eq '';  # P=R Q S
-ok 38, substr($a,-3,-5) eq '';  # P=R Q S
-ok 39, substr($a, 2,-4) eq '';  # P R Q S
-ok 40, substr($a,-3,-4) eq '';  # P R Q S
-ok 41, substr($a, 5,-6) eq '';  # R P Q=S
-ok 42, substr($a, 5,-5) eq '';  # P=R Q S
-ok 43, substr($a, 5,-3) eq '';  # P R Q=S
+like($@, $FATAL_MSG);
+is(substr($a,-5,-7), '');  # R P=Q S
+is(substr($a, 2,-7), '');  # R P Q S
+is(substr($a,-3,-7), '');  # R P Q S
+is(substr($a, 2,-5), '');  # P=R Q S
+is(substr($a,-3,-5), '');  # P=R Q S
+is(substr($a, 2,-4), '');  # P R Q S
+is(substr($a,-3,-4), '');  # P R Q S
+is(substr($a, 5,-6), '');  # R P Q=S
+is(substr($a, 5,-5), '');  # P=R Q S
+is(substr($a, 5,-3), '');  # P R Q=S
 $b = substr($a, 7,-7) ; # warn  # R P S Q
-ok 44, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 7,-7) = "" ; }; # R P S Q
-ok 45, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 $b = substr($a, 7,-5) ; # warn  # P=R S Q
-ok 46, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 7,-5) = "" ; }; # P=R S Q
-ok 47, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 $b = substr($a, 7,-3) ; # warn  # P Q S Q
-ok 48, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 7,-3) = "" ; }; # P Q S Q
-ok 49, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 $b = substr($a, 7, 0) ; # warn  # P S Q=R
-ok 50, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 7, 0) = "" ; }; # P S Q=R
-ok 51, $@ =~ /$FATAL_MSG/;
-
-ok 52, substr($a,-7,2) eq '';   # Q P=R S
-ok 53, substr($a,-7,4) eq '54'; # Q P R S
-ok 54, substr($a,-7,7) eq '54321';# Q P R=S
-ok 55, substr($a,-7,9) eq '54321';# Q P S R
-ok 56, substr($a,-5,0) eq '';   # P=Q=R S
-ok 57, substr($a,-5,3) eq '543';# P=Q R S
-ok 58, substr($a,-5,5) eq '54321';# P=Q R=S
-ok 59, substr($a,-5,7) eq '54321';# P=Q S R
-ok 60, substr($a,-3,0) eq '';   # P Q=R S
-ok 61, substr($a,-3,3) eq '321';# P Q R=S
-ok 62, substr($a,-2,3) eq '21'; # P Q S R
-ok 63, substr($a,0,-5) eq '';   # P=Q=R S
-ok 64, substr($a,2,-3) eq '';   # P Q=R S
-ok 65, substr($a,0,0) eq '';    # P=Q=R S
-ok 66, substr($a,0,5) eq '54321';# P=Q R=S
-ok 67, substr($a,0,7) eq '54321';# P=Q S R
-ok 68, substr($a,2,0) eq '';    # P Q=R S
-ok 69, substr($a,2,3) eq '321'; # P Q R=S
-ok 70, substr($a,5,0) eq '';    # P Q=R=S
-ok 71, substr($a,5,2) eq '';    # P Q=S R
-ok 72, substr($a,-7,-5) eq '';  # Q P=R S
-ok 73, substr($a,-7,-2) eq '543';# Q P R S
-ok 74, substr($a,-5,-5) eq '';  # P=Q=R S
-ok 75, substr($a,-5,-2) eq '543';# P=Q R S
-ok 76, substr($a,-3,-3) eq '';  # P Q=R S
-ok 77, substr($a,-3,-1) eq '32';# P Q R S
+like($@, $FATAL_MSG);
+
+is(substr($a,-7,2), '');   # Q P=R S
+is(substr($a,-7,4), '54'); # Q P R S
+is(substr($a,-7,7), '54321');# Q P R=S
+is(substr($a,-7,9), '54321');# Q P S R
+is(substr($a,-5,0), '');   # P=Q=R S
+is(substr($a,-5,3), '543');# P=Q R S
+is(substr($a,-5,5), '54321');# P=Q R=S
+is(substr($a,-5,7), '54321');# P=Q S R
+is(substr($a,-3,0), '');   # P Q=R S
+is(substr($a,-3,3), '321');# P Q R=S
+is(substr($a,-2,3), '21'); # P Q S R
+is(substr($a,0,-5), '');   # P=Q=R S
+is(substr($a,2,-3), '');   # P Q=R S
+is(substr($a,0,0), '');    # P=Q=R S
+is(substr($a,0,5), '54321');# P=Q R=S
+is(substr($a,0,7), '54321');# P=Q S R
+is(substr($a,2,0), '');    # P Q=R S
+is(substr($a,2,3), '321'); # P Q R=S
+is(substr($a,5,0), '');    # P Q=R=S
+is(substr($a,5,2), '');    # P Q=S R
+is(substr($a,-7,-5), '');  # Q P=R S
+is(substr($a,-7,-2), '543');# Q P R S
+is(substr($a,-5,-5), '');  # P=Q=R S
+is(substr($a,-5,-2), '543');# P=Q R S
+is(substr($a,-3,-3), '');  # P Q=R S
+is(substr($a,-3,-1), '32');# P Q R S
 
 $a = '';
 
-ok 78, substr($a,-2,2) eq '';   # Q P=R=S
-ok 79, substr($a,0,0) eq '';    # P=Q=R=S
-ok 80, substr($a,0,1) eq '';    # P=Q=S R
-ok 81, substr($a,-2,3) eq '';   # Q P=S R
-ok 82, substr($a,-2) eq '';     # Q P=R=S
-ok 83, substr($a,0) eq '';      # P=Q=R=S
+is(substr($a,-2,2), '');   # Q P=R=S
+is(substr($a,0,0), '');    # P=Q=R=S
+is(substr($a,0,1), '');    # P=Q=S R
+is(substr($a,-2,3), '');   # Q P=S R
+is(substr($a,-2), '');     # Q P=R=S
+is(substr($a,0), '');      # P=Q=R=S
 
 
-ok 84, substr($a,0,-1) eq '';   # R P=Q=S
+is(substr($a,0,-1), '');   # R P=Q=S
 $b = substr($a,-2, 0) ; # warn  # Q=R P=S
-ok 85, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-2, 0) = "" ; }; # Q=R P=S
-ok 86, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a,-2, 1) ; # warn  # Q R P=S
-ok 87, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-2, 1) = "" ; }; # Q R P=S
-ok 88, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a,-2,-1) ; # warn  # Q R P=S
-ok 89, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-2,-1) = "" ; }; # Q R P=S
-ok 90, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a,-2,-2) ; # warn  # Q=R P=S
-ok 91, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,-2,-2) = "" ; }; # Q=R P=S
-ok 92, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a, 1,-2) ; # warn  # R P=S Q
-ok 93, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 1,-2) = "" ; }; # R P=S Q
-ok 94, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a, 1, 1) ; # warn  # P=S Q R
-ok 95, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 1, 1) = "" ; }; # P=S Q R
-ok 96, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a, 1, 0) ;# warn   # P=S Q=R
-ok 97, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a, 1, 0) = "" ; }; # P=S Q=R
-ok 98, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 $b = substr($a,1) ; # warning   # P=R=S Q
-ok 99, $w-- == 1 ;
+is($w--, 1);
 eval{substr($a,1) = "" ; };     # P=R=S Q
-ok 100, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
+
+$b = substr($a,-7,-6) ; # warn  # Q R P S
+is($w--, 1);
+eval{substr($a,-7,-6) = "" ; }; # Q R P S
+like($@, $FATAL_MSG);
 
 my $a = 'zxcvbnm';
 substr($a,2,0) = '';
-ok 101, $a eq 'zxcvbnm';
+is($a, 'zxcvbnm');
 substr($a,7,0) = '';
-ok 102, $a eq 'zxcvbnm';
+is($a, 'zxcvbnm');
 substr($a,5,0) = '';
-ok 103, $a eq 'zxcvbnm';
+is($a, 'zxcvbnm');
 substr($a,0,2) = 'pq';
-ok 104, $a eq 'pqcvbnm';
+is($a, 'pqcvbnm');
 substr($a,2,0) = 'r';
-ok 105, $a eq 'pqrcvbnm';
+is($a, 'pqrcvbnm');
 substr($a,8,0) = 'asd';
-ok 106, $a eq 'pqrcvbnmasd';
+is($a, 'pqrcvbnmasd');
 substr($a,0,2) = 'iop';
-ok 107, $a eq 'ioprcvbnmasd';
+is($a, 'ioprcvbnmasd');
 substr($a,0,5) = 'fgh';
-ok 108, $a eq 'fghvbnmasd';
+is($a, 'fghvbnmasd');
 substr($a,3,5) = 'jkl';
-ok 109, $a eq 'fghjklsd';
+is($a, 'fghjklsd');
 substr($a,3,2) = '1234';
-ok 110, $a eq 'fgh1234lsd';
+is($a, 'fgh1234lsd');
 
 
 # with lexicals (and in re-entered scopes)
@@ -223,11 +222,11 @@ for (0,1) {
   unless ($_) {
     $txt = "Foo";
     substr($txt, -1) = "X";
-    ok 111, $txt eq "FoX";
+    is($txt, "FoX");
   }
   else {
     substr($txt, 0, 1) = "X";
-    ok 112, $txt eq "X";
+    is($txt, "X");
   }
 }
 
@@ -236,66 +235,75 @@ $w = 0 ;
 {
   my $s = [];
   substr($s, 0, 1) = 'Foo';
-  ok 113, substr($s,0,7) eq "FooRRAY" && !($w-=2);
+  is (substr($s,0,7), "FooRRAY");
+  is ($w,2);
+  $w = 0;
 }
 
 # check no spurious warnings
-ok 114, $w == 0;
+is($w, 0);
 
 # check new 4 arg replacement syntax
 $a = "abcxyz";
 $w = 0;
-ok 115, substr($a, 0, 3, "") eq "abc" && $a eq "xyz";
-ok 116, substr($a, 0, 0, "abc") eq "" && $a eq "abcxyz";
-ok 117, substr($a, 3, -1, "") eq "xy" && $a eq "abcz";
+is(substr($a, 0, 3, ""), "abc");
+is($a, "xyz");
+is(substr($a, 0, 0, "abc"), "");
+is($a, "abcxyz");
+is(substr($a, 3, -1, ""), "xy");
+is($a, "abcz");
 
-ok 118, substr($a, 3, undef, "xy") eq "" && $a eq "abcxyz"
-                 && $w == 3;
+is(substr($a, 3, undef, "xy"), "");
+is($a, "abcxyz");
+is($w, 3);
 
 $w = 0;
 
-ok 119, substr($a, 3, 9999999, "") eq "xyz" && $a eq "abc";
+is(substr($a, 3, 9999999, ""), "xyz");
+is($a, "abc");
 eval{substr($a, -99, 0, "") };
-ok 120, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 eval{substr($a, 99, 3, "") };
-ok 121, $@ =~ /$FATAL_MSG/;
+like($@, $FATAL_MSG);
 
 substr($a, 0, length($a), "foo");
-ok 122, $a eq "foo" && !$w;
+is ($a, "foo");
+is ($w, 0);
 
 # using 4 arg substr as lvalue is a compile time error
 eval 'substr($a,0,0,"") = "abc"';
-ok 123, $@ && $@ =~ /Can't modify substr/ && $a eq "foo";
+like ($@, qr/Can't modify substr/);
+is ($a, "foo");
 
 $a = "abcdefgh";
-ok 124, sub { shift }->(substr($a, 0, 4, "xxxx")) eq 'abcd';
-ok 125, $a eq 'xxxxefgh';
+is(sub { shift }->(substr($a, 0, 4, "xxxx")), 'abcd');
+is($a, 'xxxxefgh');
 
 {
     my $y = 10;
     $y = "2" . $y;
-    ok 126, $y+0 == 210;
+    is ($y, 210);
 }
 
 # utf8 sanity
 {
     my $x = substr("a\x{263a}b",0);
-    ok 127, length($x) == 3;
+    is(length($x), 3);
     $x = substr($x,1,1);
-    ok 128, $x eq "\x{263a}";
+    is($x, "\x{263a}");
     $x = $x x 2;
-    ok 129, length($x) == 2;
+    is(length($x), 2);
     substr($x,0,1) = "abcd";
-    ok 130, $x eq "abcd\x{263a}";
-    ok 131, length($x) == 5;
+    is($x, "abcd\x{263a}");
+    is(length($x), 5);
     $x = reverse $x;
-    ok 132, length($x) == 5;
-    ok 133, $x eq "\x{263a}dcba";
+    is(length($x), 5);
+    is($x, "\x{263a}dcba");
 
     my $z = 10;
     $z = "21\x{263a}" . $z;
-    ok 134, length($z) == 5;
-    ok 135, $z eq "21\x{263a}10";
+    is(length($z), 5);
+    is($z, "21\x{263a}10");
 }
 
 # replacement should work on magical values
@@ -303,7 +311,8 @@ require Tie::Scalar;
 my %data;
 tie $data{'a'}, 'Tie::StdScalar';  # makes $data{'a'} magical
 $data{a} = "firstlast";
-ok 136, substr($data{'a'}, 0, 5, "") eq "first" && $data{'a'} eq "last";
+is(substr($data{'a'}, 0, 5, ""), "first");
+is($data{'a'}, "last");
 
 # more utf8
 
@@ -311,277 +320,507 @@ ok 136, substr($data{'a'}, 0, 5, "") eq "first" && $data{'a'} eq "last";
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, 1) = "\x{100}"; # Ignasi had \x{FF}
-ok 137, length($x) == 3 &&
-        $x eq "\x{100}\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, 1) = "\x{100}\x{FF}"; # Ignasi had \x{FF}
-ok 138, length($x) == 4 &&
-        $x eq "\x{100}\x{FF}\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F2}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{100}\x{FF}\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F2}");
+is(substr($x, 3, 1), "\x{F3}");
 
 # more utf8 lval exercise
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, 2) = "\x{100}\xFF";
-ok 139, length($x) == 3 &&
-        $x eq "\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 1, 1) = "\x{100}\xFF";
-ok 140, length($x) == 4 &&
-        $x eq "\xF1\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{100}" &&
-        substr($x, 2, 1) eq "\x{FF}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\xF1\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{100}");
+is(substr($x, 2, 1), "\x{FF}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 2, 1) = "\x{100}\xFF";
-ok 141, length($x) == 4 &&
-        $x eq "\xF1\xF2\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}";
+is(length($x), 4);
+is($x, "\xF1\xF2\x{100}\xFF");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 3, 1) = "\x{100}\xFF";
-ok 142, length($x) == 5 &&
-        $x eq "\xF1\xF2\xF3\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{F3}" &&
-        substr($x, 3, 1) eq "\x{100}" &&
-        substr($x, 4, 1) eq "\x{FF}";
+is(length($x), 5);
+is($x, "\xF1\xF2\xF3\x{100}\xFF");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{F3}");
+is(substr($x, 3, 1), "\x{100}");
+is(substr($x, 4, 1), "\x{FF}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, -1, 1) = "\x{100}\xFF";
-ok 143, length($x) == 4 &&
-        $x eq "\xF1\xF2\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}";
+is(length($x), 4);
+is($x, "\xF1\xF2\x{100}\xFF");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, -1, 0) = "\x{100}\xFF";
-ok 144, length($x) == 5 &&
-        $x eq "\xF1\xF2\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\xF1\xF2\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
+is(substr($x, 4, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, -1) = "\x{100}\xFF";
-ok 145, length($x) == 3 &&
-        $x eq "\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, -2) = "\x{100}\xFF";
-ok 146, length($x) == 4 &&
-        $x eq "\x{100}\xFF\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F2}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{100}\xFF\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F2}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 0, -3) = "\x{100}\xFF";
-ok 147, length($x) == 5 &&
-        $x eq "\x{100}\xFF\xF1\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F1}" &&
-        substr($x, 3, 1) eq "\x{F2}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\x{100}\xFF\xF1\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F1}");
+is(substr($x, 3, 1), "\x{F2}");
+is(substr($x, 4, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, 1, -1) = "\x{100}\xFF";
-ok 148, length($x) == 4 &&
-        $x eq "\xF1\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{100}" &&
-        substr($x, 2, 1) eq "\x{FF}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\xF1\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{100}");
+is(substr($x, 2, 1), "\x{FF}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\xF1\xF2\xF3";
 substr($x, -1, -1) = "\x{100}\xFF";
-ok 149, length($x) == 5 &&
-        $x eq "\xF1\xF2\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{F1}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\xF1\xF2\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{F1}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
+is(substr($x, 4, 1), "\x{F3}");
 
 # And tests for already-UTF8 one
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, 1) = "\x{100}";
-ok 150, length($x) == 3 &&
-        $x eq "\x{100}\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, 1) = "\x{100}\x{FF}";
-ok 151, length($x) == 4 &&
-        $x eq "\x{100}\x{FF}\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F2}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{100}\x{FF}\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F2}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, 2) = "\x{100}\xFF";
-ok 152, length($x) == 3 &&
-        $x eq "\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 1, 1) = "\x{100}\xFF";
-ok 153, length($x) == 4 &&
-        $x eq "\x{101}\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{100}" &&
-        substr($x, 2, 1) eq "\x{FF}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{101}\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{100}");
+is(substr($x, 2, 1), "\x{FF}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 2, 1) = "\x{100}\xFF";
-ok 154, length($x) == 4 &&
-        $x eq "\x{101}\xF2\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}";
+is(length($x), 4);
+is($x, "\x{101}\xF2\x{100}\xFF");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 3, 1) = "\x{100}\xFF";
-ok 155, length($x) == 5 &&
-        $x eq "\x{101}\x{F2}\x{F3}\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{F3}" &&
-        substr($x, 3, 1) eq "\x{100}" &&
-        substr($x, 4, 1) eq "\x{FF}";
+is(length($x), 5);
+is($x, "\x{101}\x{F2}\x{F3}\x{100}\xFF");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{F3}");
+is(substr($x, 3, 1), "\x{100}");
+is(substr($x, 4, 1), "\x{FF}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, -1, 1) = "\x{100}\xFF";
-ok 156, length($x) == 4 &&
-        $x eq "\x{101}\xF2\x{100}\xFF" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}";
+is(length($x), 4);
+is($x, "\x{101}\xF2\x{100}\xFF");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, -1, 0) = "\x{100}\xFF";
-ok 157, length($x) == 5 &&
-        $x eq "\x{101}\xF2\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\x{101}\xF2\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
+is(substr($x, 4, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, -1) = "\x{100}\xFF";
-ok 158, length($x) == 3 &&
-        $x eq "\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F3}";
+is(length($x), 3);
+is($x, "\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, -2) = "\x{100}\xFF";
-ok 159, length($x) == 4 &&
-        $x eq "\x{100}\xFF\xF2\xF3" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{F2}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{100}\xFF\xF2\xF3");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{F2}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 0, -3) = "\x{100}\xFF";
-ok 160, length($x) == 5 &&
-        $x eq "\x{100}\xFF\x{101}\x{F2}\x{F3}" &&
-        substr($x, 0, 1) eq "\x{100}" &&
-        substr($x, 1, 1) eq "\x{FF}" &&
-        substr($x, 2, 1) eq "\x{101}" &&
-        substr($x, 3, 1) eq "\x{F2}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\x{100}\xFF\x{101}\x{F2}\x{F3}");
+is(substr($x, 0, 1), "\x{100}");
+is(substr($x, 1, 1), "\x{FF}");
+is(substr($x, 2, 1), "\x{101}");
+is(substr($x, 3, 1), "\x{F2}");
+is(substr($x, 4, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, 1, -1) = "\x{100}\xFF";
-ok 161, length($x) == 4 &&
-        $x eq "\x{101}\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{100}" &&
-        substr($x, 2, 1) eq "\x{FF}" &&
-        substr($x, 3, 1) eq "\x{F3}";
+is(length($x), 4);
+is($x, "\x{101}\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{100}");
+is(substr($x, 2, 1), "\x{FF}");
+is(substr($x, 3, 1), "\x{F3}");
 
 $x = "\x{101}\x{F2}\x{F3}";
 substr($x, -1, -1) = "\x{100}\xFF";
-ok 162, length($x) == 5 &&
-        $x eq "\x{101}\xF2\x{100}\xFF\xF3" &&
-        substr($x, 0, 1) eq "\x{101}" &&
-        substr($x, 1, 1) eq "\x{F2}" &&
-        substr($x, 2, 1) eq "\x{100}" &&
-        substr($x, 3, 1) eq "\x{FF}" &&
-        substr($x, 4, 1) eq "\x{F3}";
+is(length($x), 5);
+is($x, "\x{101}\xF2\x{100}\xFF\xF3");
+is(substr($x, 0, 1), "\x{101}");
+is(substr($x, 1, 1), "\x{F2}");
+is(substr($x, 2, 1), "\x{100}");
+is(substr($x, 3, 1), "\x{FF}");
+is(substr($x, 4, 1), "\x{F3}");
 
 substr($x = "ab", 0, 0, "\x{100}\x{200}");
-ok 163, $x eq "\x{100}\x{200}ab";
+is($x, "\x{100}\x{200}ab");
 
 substr($x = "\x{100}\x{200}", 0, 0, "ab");
-ok 164, $x eq "ab\x{100}\x{200}";
+is($x, "ab\x{100}\x{200}");
 
 substr($x = "ab", 1, 0, "\x{100}\x{200}");
-ok 165, $x eq "a\x{100}\x{200}b";
+is($x, "a\x{100}\x{200}b");
 
 substr($x = "\x{100}\x{200}", 1, 0, "ab");
-ok 166, $x eq "\x{100}ab\x{200}";
+is($x, "\x{100}ab\x{200}");
 
 substr($x = "ab", 2, 0, "\x{100}\x{200}");
-ok 167, $x eq "ab\x{100}\x{200}";
+is($x, "ab\x{100}\x{200}");
 
 substr($x = "\x{100}\x{200}", 2, 0, "ab");
-ok 168, $x eq "\x{100}\x{200}ab";
+is($x, "\x{100}\x{200}ab");
 
 substr($x = "\xFFb", 0, 0, "\x{100}\x{200}");
-ok 169, $x eq "\x{100}\x{200}\xFFb";
+is($x, "\x{100}\x{200}\xFFb");
 
 substr($x = "\x{100}\x{200}", 0, 0, "\xFFb");
-ok 170, $x eq "\xFFb\x{100}\x{200}";
+is($x, "\xFFb\x{100}\x{200}");
 
 substr($x = "\xFFb", 1, 0, "\x{100}\x{200}");
-ok 171, $x eq "\xFF\x{100}\x{200}b";
+is($x, "\xFF\x{100}\x{200}b");
 
 substr($x = "\x{100}\x{200}", 1, 0, "\xFFb");
-ok 172, $x eq "\x{100}\xFFb\x{200}";
+is($x, "\x{100}\xFFb\x{200}");
 
 substr($x = "\xFFb", 2, 0, "\x{100}\x{200}");
-ok 173, $x eq "\xFFb\x{100}\x{200}";
+is($x, "\xFFb\x{100}\x{200}");
 
 substr($x = "\x{100}\x{200}", 2, 0, "\xFFb");
-ok 174, $x eq "\x{100}\x{200}\xFFb";
+is($x, "\x{100}\x{200}\xFFb");
+
+# [perl #20933]
+{ 
+    my $s = "ab";
+    my @r; 
+    $r[$_] = \ substr $s, $_, 1 for (0, 1);
+    is(join("", map { $$_ } @r), "ab");
+}
+
+# [perl #23207]
+{
+    sub ss {
+	substr($_[0],0,1) ^= substr($_[0],1,1) ^=
+	substr($_[0],0,1) ^= substr($_[0],1,1);
+    }
+    my $x = my $y = 'AB'; ss $x; ss $y;
+    is($x, $y);
+}
+
+# [perl #24605]
+{
+    my $x = "0123456789\x{500}";
+    my $y = substr $x, 4;
+    is(substr($x, 7, 1), "7");
+}
+
+# multiple assignments to lvalue [perl #24346]   
+{
+    my $x = "abcdef";
+    for (substr($x,1,3)) {
+	is($_, 'bcd');
+	$_ = 'XX';
+	is($_, 'XX');
+	is($x, 'aXXef'); 
+	$_ = "\xFF";
+	is($_, "\xFF"); 
+	is($x, "a\xFFef");
+	$_ = "\xF1\xF2\xF3\xF4\xF5\xF6";
+	is($_, "\xF1\xF2\xF3\xF4\xF5\xF6");
+	is($x, "a\xF1\xF2\xF3\xF4\xF5\xF6ef"); 
+	$_ = 'YYYY';
+	is($_, 'YYYY'); 
+	is($x, 'aYYYYef');
+    }
+    $x = "abcdef";
+    for (substr($x,1)) {
+	is($_, 'bcdef');
+	$_ = 'XX';
+	is($_, 'XX');
+	is($x, 'aXX');
+	$x .= "frompswiggle";
+	is $_, "XXfrompswiggle";
+    }
+    $x = "abcdef";
+    for (substr($x,1,-1)) {
+	is($_, 'bcde');
+	$_ = 'XX';
+	is($_, 'XX');
+	is($x, 'aXXf');
+	$x .= "frompswiggle";
+	is $_, "XXffrompswiggl";
+    }
+    $x = "abcdef";
+    for (substr($x,-5,3)) {
+	is($_, 'bcd');
+	$_ = 'XX';   # now $_ is substr($x, -4, 2)
+	is($_, 'XX');
+	is($x, 'aXXef');
+	$x .= "frompswiggle";
+	is $_, "gg";
+    }
+    $x = "abcdef";
+    for (substr($x,-5)) {
+	is($_, 'bcdef');
+	$_ = 'XX';  # now substr($x, -2)
+	is($_, 'XX');
+	is($x, 'aXX');
+	$x .= "frompswiggle";
+	is $_, "le";
+    }
+    $x = "abcdef";
+    for (substr($x,-5,-1)) {
+	is($_, 'bcde');
+	$_ = 'XX';  # now substr($x, -3, -1)
+	is($_, 'XX');
+	is($x, 'aXXf');
+	$x .= "frompswiggle";
+	is $_, "gl";
+    }
+}
+
+# Also part of perl #24346; scalar(substr...) should not affect lvalueness
+{
+    my $str = "abcdef";
+    sub { $_[0] = 'dea' }->( scalar substr $str, 3, 2 );
+    is $str, 'abcdeaf', 'scalar does not affect lvalueness of substr';
+}
+
+# [perl #24200] string corruption with lvalue sub
+
+{
+    sub bar: lvalue { substr $krunch, 0 }
+    bar = "XXX";
+    is(bar, 'XXX');
+    $krunch = '123456789';
+    is(bar, '123456789');
+}
+
+# [perl #29149]
+{
+    my $text  = "0123456789\xED ";
+    utf8::upgrade($text);
+    my $pos = 5;
+    pos($text) = $pos;
+    my $a = substr($text, $pos, $pos);
+    is(substr($text,$pos,1), $pos);
+
+}
+
+# [perl #23765]
+{
+    my $a = pack("C", 0xbf);
+    substr($a, -1) &= chr(0xfeff);
+    is($a, "\xbf");
+}
+
+# [perl #34976] incorrect caching of utf8 substr length
+{
+    my  $a = "abcd\x{100}";
+    is(substr($a,1,2), 'bc');
+    is(substr($a,1,1), 'b');
+}
+
+# [perl #62646] offsets exceeding 32 bits on 64-bit system
+SKIP: {
+    skip("32-bit system", 24) unless ~0 > 0xffffffff;
+    my $a = "abc";
+    my $s;
+    my $r;
+
+    utf8::downgrade($a);
+    for (1..2) {
+	$w = 0;
+	$r = substr($a, 0xffffffff, 1);
+	is($r, undef);
+	is($w, 1);
+
+	$w = 0;
+	$r = substr($a, 0xffffffff+1, 1);
+	is($r, undef);
+	is($w, 1);
+
+	$w = 0;
+	ok( !eval { $r = substr($s=$a, 0xffffffff, 1, "_"); 1 } );
+	is($r, undef);
+	is($s, $a);
+	is($w, 0);
+
+	$w = 0;
+	ok( !eval { $r = substr($s=$a, 0xffffffff+1, 1, "_"); 1 } );
+	is($r, undef);
+	is($s, $a);
+	is($w, 0);
+
+	utf8::upgrade($a);
+    }
+}
+
+}
+
 
+my $destroyed;
+{ package Class; DESTROY { ++$destroyed; } }
+
+$destroyed = 0;
+{
+    my $x = '';
+    substr($x,0,1) = "";
+    $x = bless({}, 'Class');
+}
+is($destroyed, 1, 'Timely scalar destruction with lvalue substr');
+
+# [perl #77692] UTF8 cache not being reset when TARG is reused
+ok eval {
+ local ${^UTF8CACHE} = -1;
+ for my $i (0..1)
+ {
+   my $dummy = length(substr("\x{100}",0,$i));
+ }
+ 1
+}, 'UTF8 cache is reset when TARG is reused [perl #77692]';
+
+{
+    my $result_3363;
+    sub a_3363 {
+        my ($word, $replace) = @_;
+        my $ref = \substr($word, 0, 1);
+        $$ref = $replace;
+        if ($replace eq "b") {
+            $result_3363 = $word;
+        } else {
+            a_3363($word, "b");
+        }
+    }
+    a_3363($_, "v") for "test";
+
+    is($result_3363, "best", "ref-to-substr retains lvalue-ness under recursion [perl #3363]");
+}
+
+{
+    use utf8;
+    use open qw( :utf8 :std );
+    no warnings 'once';
+
+    my $t = "";
+    substr $t, 0, 0, *ワルド;
+    is($t, "*main::ワルド", "substr works on UTF-8 globs");
+
+    $t = "The World!";
+    substr $t, 0, 9, *ザ::ワルド;
+    is($t, "*ザ::ワルド!", "substr works on a UTF-8 glob + stash");
+}
+
+{
+    my $x = *foo;
+    my $y = \substr *foo, 0, 0;
+    is ref \$x, 'GLOB', '\substr does not coerce its glob arg just yet';
+    $x = \"foo";
+    $y = \substr *foo, 0, 0;
+    is ref \$x, 'REF', '\substr does not coerce its ref arg just yet';
+}