[inseperable changes from patch from perl-5.003_95 to perl-5.003_86]

[editor's note: this commit was prepared manually so may differ in
minor ways to other inseperable changes commits]

 CORE LANGUAGE CHANGES

  Title:  "Support $ENV{PERL5OPT}"
   From:  Chip Salzenberg
  Files:  perl.c pod/perldiag.pod pod/perldelta.pod pod/perlrun.pod

  Title:  "Implement void context, in which C<wantarray> is undef"
   From:  Chip Salzenberg
  Files:  cop.h doop.c dump.c global.sym gv.c op.c op.h perl.c
          pod/perlcall.pod pod/perldelta.pod pod/perlfunc.pod
          pod/perlguts.pod pod/perlsub.pod pp.c pp_ctl.c pp_hot.c
          pp_sys.c proto.h

  Title:  "Don't look up &AUTOLOAD in @ISA when calling plain function"
   From:  Chip Salzenberg
  Files:  global.sym gv.c lib/Text/ParseWords.pm pod/perldelta.pod
          pp_hot.c proto.h t/op/method.t

  Title:  "Allow closures to be constant subroutines"
   From:  Chip Salzenberg
  Files:  op.c

  Title:  "Make C<scalar(reverse)> mean C<scalar(reverse $_)>"
   From:  Chip Salzenberg
  Files:  pp.c

  Title:  "Fix lexical suicide from C<my $x = $x> in sub"
   From:  Chip Salzenberg
  Files:  op.c

  Title:  "Make "Unrecog. char." fatal, and update its doc"
   From:  Chip Salzenberg
  Files:  pod/perldiag.pod toke.c

 CORE PORTABILITY

  Title:  "safefree() mismatch"
   From:  Roderick Schertler
 Msg-ID:  <21338.859653381@eeyore.ibcinc.com>
   Date:  Sat, 29 Mar 1997 11:36:21 -0500
  Files:  util.c

    (applied based on p5p patch as commit id 9b9b466fb02dc96c81439bafbb3b2da55238cfd2)

  Title:  "Win32 update (seven patches)"
   From:  Gurusamy Sarathy and Nick Ing-Simmons
  Files:  EXTERN.h MANIFEST win32/Makefile win32/perl.mak
          win32/perl.rc win32/perldll.mak win32/makedef.pl
          win32/modules.mak win32/win32io.c win32/bin/pl2bat.bat

 OTHER CORE CHANGES

  Title:  "Report PERL* environment variables in -V and perlbug"
   From:  Chip Salzenberg
  Files:  perl.c utils/perlbug.PL

  Title:  "Typo in perl.c: Printing NO_EMBED for perl -V"
   From:  Gisle Aas
 Msg-ID:  <199703301922.VAA13509@furubotn.sn.no>
   Date:  Sun, 30 Mar 1997 21:22:11 +0200
  Files:  perl.c

    (applied based on p5p patch as commit id b6c639e4b1912ad03b9b10ba9518d96bd0a6cfaf)

  Title:  "Don't let C<$var = $var> untaint $var"
   From:  Chip Salzenberg
  Files:  pp_hot.c pp_sys.c sv.h t/op/taint.t

  Title:  "Fix autoviv bug in C<my $x; ++$x->{KEY}>"
   From:  Chip Salzenberg
  Files:  pp_hot.c

  Title:  "Re: 5.004's new srand() default seed"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703302219.AAA20998@bombur2.uio.no>
   Date:  Mon, 31 Mar 1997 00:19:13 +0200 (MET DST)
  Files:  pp.c

    (applied based on p5p patch as commit id d7d933a26349f945f93b2f0dbf85b773d8ca3219)

  Title:  "Re: embedded perl and top_env problem "
   From:  Gurusamy Sarathy
 Msg-ID:  <199703280031.TAA05711@aatma.engin.umich.edu>
   Date:  Thu, 27 Mar 1997 19:31:42 -0500
  Files:  gv.c interp.sym perl.c perl.h pp_ctl.c pp_sys.c scope.h util.c

    (applied based on p5p patch as commit id f289f7d2518e7a8a82114282e774adf50fa6ce85)

  Title:  "Define and use new macro: boolSV()"
   From:  Tim Bunce
  Files:  gv.c lib/ExtUtils/typemap os2/os2.c pp.c pp_hot.c pp_sys.c
          sv.c sv.h universal.c vms/vms.c

  Title:  "Re: strict @F"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703252110.WAA16038@bombur2.uio.no>
   Date:  Tue, 25 Mar 1997 22:10:33 +0100 (MET)
  Files:  toke.c

    (applied based on p5p patch as commit id dfd44a5c8c8dd4c001c595debfe73d011a96d844)

  Title:  "Try harder to identify errors at EOF"
   From:  Chip Salzenberg
  Files:  toke.c

  Title:  "Minor string change in toke.c: 'bareword'"
   From:  lvirden@cas.org
 Msg-ID:  <1997Mar27.130247.1911552@hmivax.humgen.upenn.edu>
   Date:  Thu, 27 Mar 1997 13:02:46 -0500 (EST)
  Files:  toke.c

    (applied based on p5p patch as commit id 9b56c8f8085a9e773ad87c6b3c1d0b5e39dbc348)

  Title:  "Improve diagnostic on \r in program text"
   From:  Chip Salzenberg
  Files:  pod/perldiag.pod toke.c

  Title:  "Make Sock_size_t typedef work right"
   From:  Chip Salzenberg
  Files:  perl.h pp_sys.c

 LIBRARY AND EXTENSIONS

  Title:  "New module constant.pm"
   From:  Tom Phoenix
  Files:  MANIFEST lib/constant.pm op.c pp.c t/pragma/constant.t

  Title:  "Remove chat2"
   From:  Chip Salzenberg
  Files:  MANIFEST lib/chat2.inter lib/chat2.pl

  Title:  "Include CGI.pm 2.32"
   From:  Chip Salzenberg
  Files:  MANIFEST eg/cgi/* lib/CGI.pm lib/CGI/Apache.pm
          lib/CGI/Carp.pm lib/CGI/Fast.pm lib/CGI/Push.pm
          lib/CGI/Switch.pm

 UTILITIES

  Title:  "Tom C's Pod::Html and html tools, as of 30 March 97"
   From:  Chip Salzenberg
  Files:  MANIFEST installhtml lib/Pod/Html.pm pod/pod2html.PL

  Title:  "Fix path bugs in installhtml"
   From:  Robin Barker <rmb1@cise.npl.co.uk>
 Msg-ID:  <3180.9703270906@tempest.cise.npl.co.uk>
   Date:  Thu, 27 Mar 97 09:06:14 GMT
  Files:  installhtml

  Title:  "Make perlbug say that it's only for core Perl bugs"
   From:  Chip Salzenberg
  Files:  utils/perlbug.PL

 DOCUMENTATION

  Title:  "Document autouse and constant; update diagnostics"
   From:  Chip Salzenberg
  Files:  pod/perldelta.pod

  Title:  "Suggest to upgraders that they try '-w' again"
   From:  Hallvard B Furuseth
 Msg-ID:  <199703251901.UAA15982@bombur2.uio.no>
   Date:  Tue, 25 Mar 1997 20:01:26 +0100 (MET)
  Files:  pod/perldelta.pod

    (applied based on p5p patch as commit id 4176c059b9ba6b022e99c44270434a5c3e415b73)

  Title:  "Improve and update documentation of constant subs"
   From:  Tom Phoenix <rootbeer@teleport.com>
 Msg-ID:  <Pine.GSO.3.96.970331122546.14185C-100000@kelly.teleport.com>
   Date:  Mon, 31 Mar 1997 13:05:54 -0800 (PST)
  Files:  pod/perlsub.pod

  Title:  "Improve documentation of C<return>"
   From:  Chip Salzenberg
  Files:  pod/perlfunc.pod pod/perlsub.pod

  Title:  "perlfunc.pod patch"
   From:  Gisle Aas
 Msg-ID:  <199703262159.WAA17531@furubotn.sn.no>
   Date:  Wed, 26 Mar 1997 22:59:23 +0100
  Files:  pod/perlfunc.pod

    (applied based on p5p patch as commit id 35a731fcbcd7860eb497d6598f3f77b8746319c4)

  Title:  "Use 'while (defined($x = <>)) {}', per <gnat@frii.com>"
   From:  Chip Salzenberg
  Files:  configpm lib/Term/Cap.pm perlsh pod/perlipc.pod pod/perlop.pod
          pod/perlsub.pod pod/perlsyn.pod pod/perltrap.pod
          pod/perlvar.pod win32/bin/search.bat

  Title:  "Document and test C<%> behavior with negative operands"
   From:  Chip Salzenberg
  Files:  pod/perlop.pod t/op/arith.t

  Title:  "Update docs on $]"
   From:  Chip Salzenberg
  Files:  pod/perlvar.pod

  Title:  "perlvar.pod patch"
   From:  Gisle Aas
 Msg-ID:  <199703261254.NAA10237@bergen.sn.no>
   Date:  Wed, 26 Mar 1997 13:54:00 +0100
  Files:  pod/perlvar.pod

    (applied based on p5p patch as commit id 0aa182cb0caa3829032904b9754807b1b7418509)

  Title:  "Fix example of C<or> vs. C<||>"
   From:  Chip Salzenberg
  Files:  pod/perlsyn.pod

  Title:  "Pod usage and spelling patch"
   From:  Larry W. Virden
  Files:  pod/*.pod

  Title:  "Pod updates"
   From:  "Cary D. Renzema" <caryr@mxim.com>
 Msg-ID:  <199703262353.PAA01819@macs.mxim.com>
   Date:  Wed, 26 Mar 1997 15:53:22 -0800 (PST)
  Files:  pod/*.pod

    (applied based on p5p patch as commit id 5695b28edc67a3f45e8a0f25755d07afef3660ac)

1 files changed, 71 insertions, 59 deletions

diff --git a/pod/perlsub.pod b/pod/perlsub.pod
index 6e2309dfb2..602e5c0dda 100644
--- a/pod/perlsub.pod
+++ b/pod/perlsub.pod
@@ -23,7 +23,7 @@ To import subroutines:
 To call subroutines:
 
     NAME(LIST);	   # & is optional with parentheses.
-    NAME LIST;	   # Parentheses optional if pre-declared/imported.
+    NAME LIST;	   # Parentheses optional if predeclared/imported.
     &NAME;	   # Passes current @_ to subroutine.
 
 =head1 DESCRIPTION
@@ -58,10 +58,14 @@ it was assigned to.)  Note that assigning to the whole array @_ removes
 the aliasing, and does not update any arguments.
 
 The return value of the subroutine is the value of the last expression
-evaluated.  Alternatively, a return statement may be used to specify the
-returned value and exit the subroutine.  If you return one or more arrays
-and/or hashes, these will be flattened together into one large
-indistinguishable list.
+evaluated.  Alternatively, a return statement may be used exit the
+subroutine, optionally specifying the returned value, which will be
+evaluated in the appropriate context (list, scalar, or void) depending
+on the context of the subroutine call.  If you specify no return value,
+the subroutine will return an empty list in a list context, an undefined
+value in a scalar context, or nothing in a void context.  If you return
+one or more arrays and/or hashes, these will be flattened together into
+one large indistinguishable list.
 
 Perl does not have named formal parameters, but in practice all you do is
 assign to a my() list of these.  Any variables you use in the function
@@ -89,7 +93,7 @@ Example:
 
     sub get_line {
 	$thisline = $lookahead;  # GLOBAL VARIABLES!!
-	LINE: while ($lookahead = <STDIN>) {
+	LINE: while (defined($lookahead = <STDIN>)) {
 	    if ($lookahead =~ /^[ \t]/) {
 		$thisline .= $lookahead;
 	    }
@@ -118,8 +122,8 @@ do in-place modifications of @_ and change its caller's values.
 
     upcase_in($v1, $v2);  # this changes $v1 and $v2
     sub upcase_in {
-	for (@_) { tr/a-z/A-Z/ } 
-    } 
+	for (@_) { tr/a-z/A-Z/ }
+    }
 
 You aren't allowed to modify constants in this way, of course.  If an
 argument were actually literal and you tried to change it, you'd take a
@@ -127,17 +131,17 @@ argument were actually literal and you tried to change it, you'd take a
 
     upcase_in("frederick");
 
-It would be much safer if the upcase_in() function 
+It would be much safer if the upcase_in() function
 were written to return a copy of its parameters instead
 of changing them in place:
 
     ($v3, $v4) = upcase($v1, $v2);  # this doesn't
     sub upcase {
+	return unless defined wantarray;  # void context, do nothing
 	my @parms = @_;
-	for (@parms) { tr/a-z/A-Z/ } 
-	# wantarray checks if we were called in list context
+	for (@parms) { tr/a-z/A-Z/ }
   	return wantarray ? @parms : $parms[0];
-    } 
+    }
 
 Notice how this (unprototyped) function doesn't care whether it was passed
 real scalars or arrays.  Perl will see everything as one big long flat @_
@@ -159,7 +163,7 @@ made @b an empty list.  See L</"Pass by Reference"> for alternatives.
 
 A subroutine may be called using the "&" prefix.  The "&" is optional
 in modern Perls, and so are the parentheses if the subroutine has been
-pre-declared.  (Note, however, that the "&" is I<NOT> optional when
+predeclared.  (Note, however, that the "&" is I<NOT> optional when
 you're just naming the subroutine, such as when it's used as an
 argument to defined() or undef().  Nor is it optional when you want to
 do an indirect subroutine call with a subroutine name or reference
@@ -179,7 +183,7 @@ new users may wish to avoid.
     &foo();		# the same
 
     &foo;		# foo() get current args, like foo(@_) !!
-    foo;		# like foo() IFF sub foo pre-declared, else "foo"
+    foo;		# like foo() IFF sub foo predeclared, else "foo"
 
 Not only does the "&" form make the argument list optional, but it also
 disables any prototype checking on the arguments you do provide.  This
@@ -226,7 +230,7 @@ this is used to name the parameters to a subroutine.  Examples:
 	my $arg = shift;  # name doesn't matter
 	$arg **= 1/3;
 	return $arg;
-    } 			
+    }
 
 The "my" is simply a modifier on something you might assign to.  So when
 you do assign to the variables in its argument list, the "my" doesn't
@@ -253,7 +257,7 @@ the current statement.  Thus,
 
     my $x = $x;
 
-can be used to initialize the new $x with the value of the old $x, and 
+can be used to initialize the new $x with the value of the old $x, and
 the expression
 
     my $x = 123 and $x == 123
@@ -264,7 +268,7 @@ Lexical scopes of control structures are not bounded precisely by the
 braces that delimit their controlled blocks; control expressions are
 part of the scope, too.  Thus in the loop
 
-    while (my $line = <>) {
+    while (defined(my $line = <>)) {
         $line = lc $line;
     } continue {
         print $line;
@@ -367,28 +371,28 @@ just enclose the whole function in an extra block, and put the
 static variable outside the function but in the block.
 
     {
-	my $secret_val = 0; 
+	my $secret_val = 0;
 	sub gimme_another {
 	    return ++$secret_val;
-	} 
-    } 
+	}
+    }
     # $secret_val now becomes unreachable by the outside
     # world, but retains its value between calls to gimme_another
 
-If this function is being sourced in from a separate file 
+If this function is being sourced in from a separate file
 via C<require> or C<use>, then this is probably just fine.  If it's
-all in the main program, you'll need to arrange for the my() 
+all in the main program, you'll need to arrange for the my()
 to be executed early, either by putting the whole block above
-your pain program, or more likely, placing merely a BEGIN 
+your pain program, or more likely, placing merely a BEGIN
 sub around it to make sure it gets executed before your program
 starts to run:
 
     sub BEGIN {
-	my $secret_val = 0; 
+	my $secret_val = 0;
 	sub gimme_another {
 	    return ++$secret_val;
-	} 
-    } 
+	}
+    }
 
 See L<perlrun> about the BEGIN function.
 
@@ -412,7 +416,7 @@ Synopsis:
     local *merlyn = *randal;	# now $merlyn is really $randal, plus
                                 #     @merlyn is really @randal, etc
     local *merlyn = 'randal';	# SAME THING: promote 'randal' to *randal
-    local *merlyn = \$randal;   # just alias $merlyn, not @merlyn etc 
+    local *merlyn = \$randal;   # just alias $merlyn, not @merlyn etc
 
 A local() modifies its listed variables to be local to the enclosing
 block, (or subroutine, C<eval{}>, or C<do>) and I<any called from
@@ -433,9 +437,9 @@ subroutine.  Examples:
 
     for $i ( 0 .. 9 ) {
 	$digits{$i} = $i;
-    } 
+    }
     # assume this function uses global %digits hash
-    parse_num();  
+    parse_num();
 
     # now temporarily add to %digits hash
     if ($base12) {
@@ -525,29 +529,29 @@ list of all their former last elements:
 	my @retlist = ();
 	foreach $aref ( @_ ) {
 	    push @retlist, pop @$aref;
-	} 
+	}
 	return @retlist;
-    } 
+    }
 
-Here's how you might write a function that returns a 
+Here's how you might write a function that returns a
 list of keys occurring in all the hashes passed to it:
 
-    @common = inter( \%foo, \%bar, \%joe ); 
+    @common = inter( \%foo, \%bar, \%joe );
     sub inter {
 	my ($k, $href, %seen); # locals
 	foreach $href (@_) {
 	    while ( $k = each %$href ) {
 		$seen{$k}++;
-	    } 
-	} 
+	    }
+	}
 	return grep { $seen{$_} == @_ } keys %seen;
-    } 
+    }
 
 So far, we're using just the normal list return mechanism.
-What happens if you want to pass or return a hash?  Well, 
-if you're using only one of them, or you don't mind them 
+What happens if you want to pass or return a hash?  Well,
+if you're using only one of them, or you don't mind them
 concatenating, then the normal calling convention is ok, although
-a little expensive.  
+a little expensive.
 
 Where people get into trouble is here:
 
@@ -572,8 +576,8 @@ in order of how many elements they have in them:
 	    return ($cref, $dref);
 	} else {
 	    return ($dref, $cref);
-	} 
-    } 
+	}
+    }
 
 It turns out that you can actually do this also:
 
@@ -585,8 +589,8 @@ It turns out that you can actually do this also:
 	    return (\@c, \@d);
 	} else {
 	    return (\@d, \@c);
-	} 
-    } 
+	}
+    }
 
 Here we're using the typeglobs to do symbol table aliasing.  It's
 a tad subtle, though, and also won't work if you're using my()
@@ -617,7 +621,7 @@ If you're planning on generating new filehandles, you could do this:
 	my $name = shift;
 	local *FH;
 	return open (FH, $path) ? *FH : undef;
-    } 
+    }
 
 Although that will actually produce a small memory leak.  See the bottom
 of L<perlfunc/open()> for a somewhat cleaner way using the IO::Handle
@@ -744,7 +748,7 @@ if you decide that a function should take just one parameter, like this:
     sub func ($) {
 	my $n = shift;
 	print "you gave me $n\n";
-    } 
+    }
 
 and someone has been calling it with an array or expression
 returning a list:
@@ -760,15 +764,17 @@ in @foo.  And the split() gets called in a scalar context and
 starts scribbling on your @_ parameter list.
 
 This is all very powerful, of course, and should be used only in moderation
-to make the world a better place.  
+to make the world a better place.
 
 =head2 Constant Functions
 
 Functions with a prototype of C<()> are potential candidates for
-inlining.  If the result after optimization and constant folding is a
-constant then it will be used in place of new-style calls to the
-function.  Old-style calls (that is, calls made using C<&>) are not
-affected.
+inlining.  If the result after optimization and constant folding is
+either a constant or a lexically-scoped scalar which has no other
+references, then it will be used in place of function calls made
+without C<&> or C<do>. Calls made using C<&> or C<do> are never
+inlined.  (See constant.pm for an easy way to declare most
+constants.)
 
 All of the following functions would be inlined.
 
@@ -781,8 +787,8 @@ All of the following functions would be inlined.
     sub FLAG_FOO ()	{ 1 << 8 }
     sub FLAG_BAR ()	{ 1 << 9 }
     sub FLAG_MASK ()	{ FLAG_FOO | FLAG_BAR }
-    
-    sub OPT_BAZ ()	{ 1 }
+
+    sub OPT_BAZ ()	{ not (0x1B58 & FLAG_MASK) }
     sub BAZ_VAL () {
 	if (OPT_BAZ) {
 	    return 23;
@@ -792,6 +798,13 @@ All of the following functions would be inlined.
 	}
     }
 
+    sub N () { int(BAZ_VAL) / 3 }
+    BEGIN {
+	my $prod = 1;
+	for (1..N) { $prod *= $_ }
+	sub N_FACTORIAL () { $prod }
+    }
+
 If you redefine a subroutine which was eligible for inlining you'll get
 a mandatory warning.  (You can use this warning to tell whether or not a
 particular subroutine is considered constant.)  The warning is
@@ -802,9 +815,8 @@ ensure that it isn't inlined, either by dropping the C<()> prototype
 (which changes the calling semantics, so beware) or by thwarting the
 inlining mechanism in some other way, such as
 
-    my $dummy;
     sub not_inlined () {
-    	$dummy || 23
+    	23 if $];
     }
 
 =head2 Overriding Builtin Functions
@@ -816,7 +828,7 @@ on a non-Unix system.
 
 Overriding may be done only by importing the name from a
 module--ordinary predeclaration isn't good enough.  However, the
-C<subs> pragma (compiler directive) lets you, in effect, pre-declare subs
+C<subs> pragma (compiler directive) lets you, in effect, predeclare subs
 via the import syntax, and these names may then override the builtin ones:
 
     use subs 'chdir', 'chroot', 'chmod', 'chown';
@@ -864,12 +876,12 @@ should just call system() with those arguments.  All you'd do is this:
 	my $program = $AUTOLOAD;
 	$program =~ s/.*:://;
 	system($program, @_);
-    } 
+    }
     date();
     who('am', 'i');
     ls('-l');
 
-In fact, if you pre-declare the functions you want to call that way, you don't
+In fact, if you predeclare the functions you want to call that way, you don't
 even need the parentheses:
 
     use subs qw(date who ls);
@@ -889,6 +901,6 @@ functions to perl code in L<perlxs>.
 =head1 SEE ALSO
 
 See L<perlref> for more on references.  See L<perlxs> if you'd
-like to learn about calling C subroutines from perl.  See 
-L<perlmod> to learn about bundling up your functions in 
+like to learn about calling C subroutines from perl.  See
+L<perlmod> to learn about bundling up your functions in
 separate files.