Integrate mainline

p4raw-id: //depot/perlio@8406

10 files changed, 376 insertions, 12 deletions

diff --git a/Changes b/Changes
index c628e27c99..eaa6aac8ff 100644
--- a/Changes
+++ b/Changes
@@ -32,6 +32,206 @@ Version v5.7.1		Development release working toward v5.8
 --------------
 
 ____________________________________________________________________________
+[  8403] By: jhi                                   on 2001/01/11  04:38:24
+        Log: Subject: Re: [ID 20001029.005] Regex error: "cd. (A. Tw)" !~ /\((\w\. \w+)\)/
+             From: Hugo <hv@crypt.compulink.co.uk>
+             Date: Mon, 30 Oct 2000 01:33:26 +0000
+             Message-Id: <200010300133.BAA10390@crypt.compulink.co.uk>
+     Branch: perl
+	   ! regexec.c t/op/re_tests
+____________________________________________________________________________
+[  8402] By: jhi                                   on 2001/01/11  04:26:12
+        Log: Integrate perlio.
+     Branch: perl
+	  !> scope.h util.c
+____________________________________________________________________________
+[  8401] By: nick                                  on 2001/01/10  22:52:55
+        Log: Allow control of 2nd arg to segsetjmp() via -DSCOPE_SAVES_SIGNAL_MASK.
+             (So Alan and Ilya can try setting via hints.)
+             Verified Linux "works" with it true and fails to re-enable SIGINT if false.
+             Restoring sigmask in Perl_sighandler() if handler dies is not equivalent;
+             doing the save everywhere seems to restart read() correctly, but just
+             doing it once "round" the handler does not.
+     Branch: perlio
+	   ! scope.h
+____________________________________________________________________________
+[  8400] By: jhi                                   on 2001/01/10  21:57:54
+        Log: Not defining PERL_PRESERVE_IVUV fixes only the op/inc problem
+             of IRIX, HP-UX is unaffected.
+     Branch: perl
+	   ! perl.h
+____________________________________________________________________________
+[  8399] By: nick                                  on 2001/01/10  21:29:19
+        Log: Safe fix for Simon's pclose() doing SvIVX of undef -> core bug.
+     Branch: perlio
+	   ! util.c
+____________________________________________________________________________
+[  8398] By: jhi                                   on 2001/01/10  20:55:31
+        Log: Add ReuseAddr as a (preferred) alias for Reuse as we know
+             also have ReusePort.
+     Branch: perl
+	   ! ext/IO/lib/IO/Socket/INET.pm
+____________________________________________________________________________
+[  8397] By: jhi                                   on 2001/01/10  20:50:57
+        Log: Subject: [PATCH] add ReusePort option to IO::Socket::INET for better multicast support (resend)
+             From: "Jeremy D. Zawodny" <jzawodn@yahoo-inc.com>
+             Date: Wed, 10 Jan 2001 01:38:13 -0800
+             Message-ID: <20010110013813.B41744@yahoo-inc.com>
+     Branch: perl
+	   ! ext/IO/lib/IO/Socket/INET.pm
+____________________________________________________________________________
+[  8396] By: jhi                                   on 2001/01/10  20:49:30
+        Log: Subject: [PATCH] add SO_REUSEPORT to export list in Socket.pm for better multicast support (resend)
+             From: "Jeremy D. Zawodny" <jzawodn@yahoo-inc.com>
+             Date: Wed, 10 Jan 2001 01:37:32 -0800
+             Message-ID: <20010110013732.A41744@yahoo-inc.com>
+     Branch: perl
+	   ! ext/Socket/Socket.pm
+____________________________________________________________________________
+[  8395] By: jhi                                   on 2001/01/10  20:41:37
+        Log: Test for bug id 20010105.016 (fixed by #8378).
+     Branch: perl
+	   ! t/op/split.t
+____________________________________________________________________________
+[  8394] By: jhi                                   on 2001/01/10  20:26:32
+        Log: Integrate perlio.
+     Branch: perl
+	   ! util.c
+____________________________________________________________________________
+[  8393] By: nick                                  on 2001/01/10  19:34:30
+        Log: Back out Simon's pid hackery for now.
+     Branch: perlio
+	   ! util.c
+____________________________________________________________________________
+[  8392] By: nick                                  on 2001/01/10  19:23:13
+        Log: Integrate mainline. (Builds but does not work - something broke pipes...)
+     Branch: perlio
+	  !> (integrate 29 files)
+____________________________________________________________________________
+[  8391] By: jhi                                   on 2001/01/10  18:43:15
+        Log: Subject: [PATCH] Fix my_pclose segfault
+             From: Simon Cozens <simon@cozens.net>
+             Date: Wed, 10 Jan 2001 18:39:35 +0000
+             Message-ID: <20010110183934.A25640@pembro26.pmb.ox.ac.uk>
+     Branch: perl
+	   ! util.c
+____________________________________________________________________________
+[  8390] By: jhi                                   on 2001/01/10  18:42:08
+        Log: Subject:  [PATCH perl@8269] Opcode.XS, fix memory leak
+             From: lane@DUPHY4.Physics.Drexel.Edu (Charles Lane)
+             Date:     Wed, 10 Jan 2001 13:23:02 EST
+             Message-Id: <010110132245.8129a@DUPHY4.Physics.Drexel.Edu>
+     Branch: perl
+	   ! ext/Opcode/Opcode.xs
+____________________________________________________________________________
+[  8389] By: jhi                                   on 2001/01/10  15:16:07
+        Log: Turn off the integer preservation for now.
+     Branch: perl
+	   ! perl.h
+____________________________________________________________________________
+[  8388] By: jhi                                   on 2001/01/10  15:01:25
+        Log: Few more IDE/editor nits from p5p.
+     Branch: perl
+	   ! pod/perlfaq3.pod
+____________________________________________________________________________
+[  8387] By: jhi                                   on 2001/01/10  06:53:16
+        Log: Subject: Re: [ID 20010109.003] Patch 8138 broke a test in libwww
+             To: "Andreas J. Koenig" <andreas.koenig@anima.de>
+             Date: Tue, 9 Jan 2001 23:16:02 +0000
+             Message-ID: <20010109231602.A81101@plum.flirble.org>
+     Branch: perl
+	   ! sv.c
+____________________________________________________________________________
+[  8386] By: jhi                                   on 2001/01/10  03:17:54
+        Log: Test cases for #8385 (from Simon's "torture.pl")
+     Branch: perl
+	   ! t/op/tr.t
+____________________________________________________________________________
+[  8385] By: jhi                                   on 2001/01/10  03:17:11
+        Log: Subject: Re: more UTF8 test suites and an UTF8 patch
+             From: Inaba Hiroto <inaba@sdd.tokyo-sc.toshiba.co.jp>
+             Date: Wed, 10 Jan 2001 11:39:39 +0900
+             Message-Id: <10101100239.AA10002@tux0017.sdd.tokyo-sc.toshiba.co.jp>
+             
+             Some more UTF-8 tr cases fixed.
+     Branch: perl
+	   ! doop.c
+____________________________________________________________________________
+[  8384] By: jhi                                   on 2001/01/09  22:45:40
+        Log: Allow the locale test needing POSIX and the taint test
+             needing IPC::SysV to run under 'minitest' (basically,
+             bail out if loading the extension fails)
+     Branch: perl
+	   ! t/op/misc.t t/op/taint.t
+____________________________________________________________________________
+[  8383] By: jhi                                   on 2001/01/09  21:36:04
+        Log: Subject: [PATCH @8382] Remove FileHandle/IO dependence in t/io/openpid.t
+             From: Stephen McCamant <smcc@CSUA.Berkeley.EDU>
+             Date: Tue,  9 Jan 2001 13:33:22 -0800 (PST)
+             Message-ID: <14939.33475.474459.147429@soda.csua.berkeley.edu>
+     Branch: perl
+	   ! t/io/openpid.t
+____________________________________________________________________________
+[  8382] By: jhi                                   on 2001/01/09  21:06:08
+        Log: save_delete(), err, SAVEDELETE() fixes from Charles Lane.
+             Should finish up the bug id 20001205.022.
+     Branch: perl
+	   ! pp.c pp_hot.c scope.c
+____________________________________________________________________________
+[  8381] By: jhi                                   on 2001/01/09  18:27:43
+        Log: Subject: Re: [PATCH: perl@8342] comp/proto..........FAILED tests 112-123
+             From: Andy Dougherty <doughera@lafayette.edu>
+             Date: Tue, 9 Jan 2001 12:11:16 -0500 (EST)
+             Message-ID: <Pine.SOL.4.10.10101091144440.13124-100000@maxwell.phys.lafayette.edu>
+             
+             More robust yacc/bison error detection.
+     Branch: perl
+	   ! t/comp/proto.t
+____________________________________________________________________________
+[  8380] By: jhi                                   on 2001/01/09  15:21:38
+        Log: Subject:  [PATCH] make t/op/misc.t work on VMS
+             From: lane@DUPHY4.Physics.Drexel.Edu (Charles Lane)
+             Date:     Tue, 9 Jan 2001 07:53:55 EST
+             Message-Id: <010109075323.91c8f@DUPHY4.Physics.Drexel.Edu> 
+     Branch: perl
+	   ! t/op/misc.t vms/test.com
+____________________________________________________________________________
+[  8379] By: jhi                                   on 2001/01/09  15:20:38
+        Log: Subject: [ID 20001230.003] UTF-8 tr still hurts
+             From: jhi@cc.hut.fi
+             Date: Sat, 30 Dec 2000 22:57:32 +0200 (EET)
+             Message-Id: <200012302057.WAA31168@alpha.hut.fi>
+             
+             The #8378 fixed this.
+     Branch: perl
+	   ! t/op/tr.t
+____________________________________________________________________________
+[  8378] By: jhi                                   on 2001/01/09  15:05:32
+        Log: Subject: One more patch for UTF8 
+             From: Inaba Hiroto <inaba@st.rim.or.jp>
+             Date: Tue, 09 Jan 2001 01:04:32 +0900
+             Message-ID: <3A59E510.52BAB5B9@st.rim.or.jp>
+             
+             UTF-8 fixes for 'x' and tr///.
+     Branch: perl
+	   ! doop.c embed.h embed.pl op.c pod/perlapi.pod pp.c proto.h
+	   ! regcomp.c regexec.c toke.c utf8.c
+____________________________________________________________________________
+[  8377] By: jhi                                   on 2001/01/09  14:32:17
+        Log: Make explicit our assumption that (for now) "\x{80}" produces UTF-8.
+     Branch: perl
+	   ! t/op/length.t
+____________________________________________________________________________
+[  8376] By: jhi                                   on 2001/01/09  04:32:32
+        Log: integrate changes #7775, #8316, #8316 from mainline
+     Branch: maint-5.6/perl
+	   ! hints/solaris_2.sh
+____________________________________________________________________________
+[  8375] By: jhi                                   on 2001/01/09  04:26:43
+        Log: Update Changes.
+     Branch: perl
+	   ! Changes patchlevel.h
+____________________________________________________________________________
 [  8374] By: jhi                                   on 2001/01/09  04:14:32
         Log: IDE/editor section tweaking.
      Branch: perl
@@ -175,7 +375,7 @@ ____________________________________________________________________________
 	   ! lib/ExtUtils/typemap perlio.c perlio.h
 ____________________________________________________________________________
 [  8355] By: jhi                                   on 2001/01/06  20:27:15
-        Log: integrate change #8836 from mainline
+        Log: integrate change #8336 from mainline
              
              Scoping of %^H still broken in both perl@8269 and perl-5.6.1-TRIAL1
      Branch: maint-5.6/perl
diff --git a/ext/IO/lib/IO/Socket/INET.pm b/ext/IO/lib/IO/Socket/INET.pm
index c922bf35c9..d2cc488dd2 100644
--- a/ext/IO/lib/IO/Socket/INET.pm
+++ b/ext/IO/lib/IO/Socket/INET.pm
@@ -151,11 +151,16 @@ sub configure {
 	$sock->socket(AF_INET, $type, $proto) or
 	    return _error($sock, $!, "$!");
 
-	if ($arg->{Reuse}) {
+	if ($arg->{Reuse} || $arg->{ReuseAddr}) {
 	    $sock->sockopt(SO_REUSEADDR,1) or
 		    return _error($sock, $!, "$!");
 	}
 
+	if ($arg->{ReusePort}) {
+	    $sock->sockopt(SO_REUSEPORT,1) or
+		    return _error($sock, $!, "$!");
+	}
+
 	if($lport || ($laddr ne INADDR_ANY) || exists $arg->{Listen}) {
 	    $sock->bind($lport || 0, $laddr) or
 		    return _error($sock, $!, "$!");
@@ -302,7 +307,9 @@ C<IO::Socket::INET> provides.
     Proto	Protocol name (or number)    "tcp" | "udp" | ...
     Type	Socket type                  SOCK_STREAM | SOCK_DGRAM | ...
     Listen	Queue size for listen
-    Reuse	Set SO_REUSEADDR before binding
+    ReuseAddr	Set SO_REUSEADDR before binding
+    Reuse	Set SO_REUSEADDR before binding (deprecated, prefer ReuseAddr)
+    ReusePort	Set SO_REUSEPORT before binding
     Timeout	Timeout	value for various operations
     MultiHomed  Try all adresses for multi-homed hosts
 
diff --git a/ext/Socket/Socket.pm b/ext/Socket/Socket.pm
index b4a0419cbc..90e16e6e19 100644
--- a/ext/Socket/Socket.pm
+++ b/ext/Socket/Socket.pm
@@ -268,6 +268,7 @@ use XSLoader ();
 	SO_RCVLOWAT
 	SO_RCVTIMEO
 	SO_REUSEADDR
+	SO_REUSEPORT
 	SO_SNDBUF
 	SO_SNDLOWAT
 	SO_SNDTIMEO
diff --git a/mg.c b/mg.c
index 3a61655678..ca06b891fc 100644
--- a/mg.c
+++ b/mg.c
@@ -1417,15 +1417,25 @@ Perl_magic_getsubstr(pTHX_ SV *sv, MAGIC *mg)
 int
 Perl_magic_setsubstr(pTHX_ SV *sv, MAGIC *mg)
 {
-    STRLEN len;
-    char *tmps = SvPV(sv,len);
+    STRLEN littlelen;
+    char *tmps = SvPV(sv, littlelen);
+
     if (DO_UTF8(sv)) {
+	I32 bigoff = LvTARGOFF(sv);
+	I32 biglen = LvTARGLEN(sv);
+	U8 *s, *a, *b;
+
 	sv_utf8_upgrade(LvTARG(sv));
-	sv_insert(LvTARG(sv),LvTARGOFF(sv),LvTARGLEN(sv), tmps, len);
+	/* sv_utf8_upgrade() might have moved and/or resized
+	 * the string to be replaced, we must rediscover it. --jhi */
+	s = (U8*)SvPVX(LvTARG(sv));
+	a = utf8_hop(s, bigoff);
+	b = utf8_hop(a, biglen);
+	sv_insert(LvTARG(sv), a - s, b - a, tmps, littlelen);
 	SvUTF8_on(LvTARG(sv));
     }
     else
-        sv_insert(LvTARG(sv),LvTARGOFF(sv),LvTARGLEN(sv), tmps, len);
+        sv_insert(LvTARG(sv), LvTARGOFF(sv), LvTARGLEN(sv), tmps, littlelen);
 
     return 0;
 }
diff --git a/patchlevel.h b/patchlevel.h
index 574869a0e2..30397891a9 100644
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -70,7 +70,7 @@
 #if !defined(PERL_PATCHLEVEL_H_IMPLICIT) && !defined(LOCAL_PATCH_COUNT)
 static	char	*local_patches[] = {
         NULL
-	,"DEVEL8374"
+	,"DEVEL8403"
 	,NULL
 };
 
diff --git a/perl.h b/perl.h
index 41b1c2a211..19827a3101 100644
--- a/perl.h
+++ b/perl.h
@@ -1084,7 +1084,6 @@ typedef UVTYPE UV;
 #define IV_DIG (BIT_DIGITS(IVSIZE * 8))
 #define UV_DIG (BIT_DIGITS(UVSIZE * 8))
 
-#define NO_PERL_PRESEVE_IVUV	/* Not finished yet. */
 #ifndef NO_PERL_PRESERVE_IVUV
 #define PERL_PRESERVE_IVUV	/* We like our integers to stay integers. */
 #endif
diff --git a/regexec.c b/regexec.c
index 5990ea3ca4..c7d42cda4e 100644
--- a/regexec.c
+++ b/regexec.c
@@ -597,7 +597,7 @@ Perl_re_intuit_start(pTHX_ regexp *prog, SV *sv, char *strpos,
 		    DEBUG_r(PerlIO_printf(Perl_debug_log,
 			", trying anchored starting at offset %ld...\n",
 			(long)(s1 + 1 - i_strpos)));
-		    other_last = last + 1;
+		    other_last = last; /* Fix this later. --Hugo */
 		    s = HOP3c(t, 1, strend);
 		    goto restart;
 		}
diff --git a/t/op/re_tests b/t/op/re_tests
index 52666daea5..1090e112b9 100644
--- a/t/op/re_tests
+++ b/t/op/re_tests
@@ -781,3 +781,4 @@ tt+$	xxxtt	y	-	-
 ^([0-9a-fA-F]+)(?:x([0-9a-fA-F]+)?)(?:x([0-9a-fA-F]+))?	012cxx0190	y	-	-
 ^(b+?|a){1,2}c	bbbac	y	$1	a
 ^(b+?|a){1,2}c	bbbbac	y	$1	a
+\((\w\. \w+)\)	cd. (A. Tw)	y	-$1-	-A. Tw-
diff --git a/t/op/split.t b/t/op/split.t
index 90c38e0770..ffc29be899 100755
--- a/t/op/split.t
+++ b/t/op/split.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..30\n";
+print "1..32\n";
 
 $FS = ':';
 
@@ -129,6 +129,27 @@ print "not" if $_ ne "r:m :b";
 print "ok 29\n";
 
 # unicode splittage
+
 @ary = map {ord} split //, v1.20.300.4000.50000.4000.300.20.1;
 print "not " unless "@ary" eq "1 20 300 4000 50000 4000 300 20 1";
 print "ok 30\n";
+
+@ary = split(/\x{FE}/, "\x{FF}\x{FE}\x{FD}"); # bug id 20010105.016
+print "not " unless @ary == 2 &&
+                    $ary[0] eq "\xFF"   && $ary[1] eq "\xFD" &&
+                    $ary[0] eq "\x{FF}" && $ary[1] eq "\x{FD}";
+print "ok 31\n";
+
+@ary = split(/(\x{FE}\xFE)/, "\xFF\x{FF}\xFE\x{FE}\xFD\x{FD}"); # variant of 31
+print "not " unless @ary == 3 &&
+                    $ary[0] eq "\xFF\xFF"     &&
+                    $ary[0] eq "\x{FF}\xFF"   &&
+                    $ary[0] eq "\x{FF}\x{FF}" &&
+                    $ary[1] eq "\xFE\xFE"     &&
+                    $ary[1] eq "\x{FE}\xFE"   &&
+                    $ary[1] eq "\x{FE}\x{FE}" &&
+                    $ary[2] eq "\xFD\xFD"     &&
+                    $ary[2] eq "\x{FD}\xFD"   &&
+                    $ary[2] eq "\x{FD}\x{FD}";
+
+print "ok 32\n";
diff --git a/t/op/substr.t b/t/op/substr.t
index 4d3bbce927..d3937fb107 100755
--- a/t/op/substr.t
+++ b/t/op/substr.t
@@ -1,6 +1,6 @@
 #!./perl
 
-print "1..136\n";
+print "1..149\n";
 
 #P = start of string  Q = start of substr  R = end of substr  S = end of string
 
@@ -304,3 +304,128 @@ my %data;
 tie $data{'a'}, 'Tie::StdScalar';  # makes $data{'a'} magical
 $data{a} = "firstlast";
 ok 136, substr($data{'a'}, 0, 5, "") eq "first" && $data{'a'} eq "last";
+
+# more utf8
+
+# The following two originally from Ignasi Roca.
+
+$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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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($x, 3, 1) eq "\x{F3}";
+
+# more utf8 lval exercise
+
+$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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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($x, 3, 1) eq "\x{F3}";
+
+$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($x, 3, 1) eq "\x{FF}";
+
+$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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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($x, 3, 1) eq "\x{FF}";
+
+$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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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($x, 3, 1) eq "\x{F3}";
+
+$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}";
+
+$x = "\xF1\xF2\xF3";
+substr($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($x, 3, 1) eq "\x{F3}";
+
+$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}";
+