[inseparable changes from patch from perl5.003_22 to perl5.003_23]perl-5.003_23

 BUILD PROCESS

Subject: Make configure.gnu a copy of configure; make configure writea
From: Chip Salzenberg <chip@atlantic.net>
Files: MANIFEST configure.gnu

Subject: Regen Configure with metaconfig: +ARCHNAME, -FILE_filbuf
From: Chip Salzenberg <chip@perl.com>
Files: Configure config_H config_h.SH hints/lynxos.sh os2/diff.configure os2/os2ish.h plan9/config.plan9 sv.c utils/perlbug.PL vms/config.vms vms/fndvers.com

Subject: Compile with optimization when testing memory functions
From: Chip Salzenberg <chip@atlantic.net>
Files: Configure

 CORE LANGUAGE CHANGES

Subject: Disallow changing $_[0] in __DIE__ handlers
From: Chip Salzenberg <chip@atlantic.net>
Files: pod/perlfunc.pod util.c

Subject: Fix overloading with inheritance and AUTOLOAD
Date: Mon, 20 Jan 1997 17:26:32 -0500 (EST)
From: Ilya Zakharevich <ilya@math.ohio-state.edu>
Files: gv.c lib/diagnostics.pm lib/overload.pm pod/perldebug.pod pod/perldiag.pod pod/perlfunc.pod pod/perlop.pod pod/perlre.pod pod/perltoc.pod pod/perlxs.pod
Msg-ID: <199701202226.RAA05072@monk.mps.ohio-state.edu>

    (applied based on p5p patch as commit e7ea3e70155d0bea30720ba41eb6bb6742aac0d1)

Subject: Nested here-docs
Date: Mon, 20 Jan 1997 15:13:42 -0800
From: Larry Wall <larry@wall.org>
Files: toke.c
Msg-ID: <199701202313.PAA11693@wall.org>

    (applied based on p5p patch as commit fd2d0953290ddd46f0820dbd6c87245486b7ab28)

Subject: Revert $^X to old behavior (plus HP-UX bug fix)
From: Chip Salzenberg <chip@atlantic.net>
Files: hints/hpux.sh toke.c

Subject: Protect against '0' in 'stmt while <HANDLE>'
From: Chip Salzenberg <chip@atlantic.net>
Files: op.c

Subject: Don't warn when closure uses var at file scope
From: Chip Salzenberg <chip@atlantic.net>
Files: op.c

 CORE PORTABILITY

Subject: VMS patches for _22
Date: Mon, 20 Jan 1997 22:50:21 -0500 (EST)
From: Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>
Files: ext/POSIX/POSIX.xs lib/ExtUtils/MM_VMS.pm lib/ExtUtils/xsubpp lib/Test/Harness.pm toke.c vms/Makefile vms/descrip.mms vms/genconfig.pl vms/perly_c.vms vms/vmsish.h x2p/a2p.h vms/Makefile vms/config.vms vms/descrip.mms vms/perly_c.vms

    private-msgid: <01IEGBJ2TMYS003PCL@hmivax.humgen.upenn.edu>

Subject: Plan9 update
From: Luther Huffman <lutherh@stratcom.com>
Files: plan9/config.plan9 plan9/mkfile

Subject: hints & Configure changes to build perl on DC/OSx
Date: Thu, 16 Jan 1997 16:43:52 -0800
From: Stephen Zander <stephen.zander@interlock.mckesson.com>
Files: Configure MANIFEST hints/dcosx.sh
Msg-ID: <199701170043.QAA25985@wsbip1.mckesson.com>

    (applied based on p5p patch as commit 23f8769697279d7912be5943de9fdf93f6aa3013)

 DOCUMENTATION

Subject: Additional docs for __DIE__ and __WARN__
From: Gurusamy Sarathy <gsar@engin.umich.edu>
Files: pod/perlfunc.pod pod/perlrun.pod pod/perlvar.pod

Subject: Document #line directive
Date: Fri, 24 Jan 1997 04:08:44 -0500
From: Gurusamy Sarathy <gsar@engin.umich.edu>
Files: pod/perlsyn.pod pod/perltoc.pod

    private-msgid: <199701240908.EAA23846@aatma.engin.umich.edu>

Subject: delta for perldelta
Date: Fri, 24 Jan 1997 07:57:43 -0800
From: Tom Christiansen <tchrist@mox.perl.com>
Files: pod/perlnews.pod pod/perltoc.pod

    private-msgid: <804.854121463@jinete>

Subject: Updates to perldelta
Date: Mon, 20 Jan 1997 06:48:49 -0500 (EST)
From: Ilya Zakharevich <ilya@math.ohio-state.edu>
Files: pod/perlnews.pod pod/perltoc.pod

    private-msgid: <199701211610.LAA06227@monk.mps.ohio-state.edu>

Subject: perlnews.pod diff for the Fcntl
Date: Tue, 21 Jan 1997 18:00:56 +0200 (EET)
From: Jarkko Hietaniemi <jhi@cc.hut.fi>
Files: pod/perlnews.pod

    private-msgid: <199701211600.SAA30117@alpha.hut.fi>

Subject: Rename perlnews -> perldelta per Tom's request
From: Chip Salzenberg <chip@atlantic.net>
Files: MANIFEST pod/Makefile pod/buildtoc pod/perl.pod pod/perldelta.pod pod/perltoc.pod pod/roffitall

 LIBRARY AND EXTENSIONS

Subject: Refresh IO to 1.15 (plus DESTROY and new_tmpfile fixes)
From: Chip Salzenberg <chip@atlantic.net>
Files: ext/IO/lib/IO/File.pm ext/IO/lib/IO/Handle.pm ext/IO/lib/IO/Pipe.pm ext/IO/lib/IO/Seekable.pm ext/IO/lib/IO/Socket.pm t/lib/io_pipe.t

Subject: Allow IO.xs to remain at 1.15 while $VERSION is 1.1501
From: Chip Salzenberg <chip@atlantic.net>
Files: XSUB.h ext/IO/Makefile.PL ext/IO/lib/IO/Handle.pm

Subject: Add E* and SA_* constants
Date: Wed, 22 Jan 1997 21:36:07 -0500
From: Roderick Schertler <roderick@gate.net>
Files: ext/POSIX/POSIX.pm ext/POSIX/POSIX.pod ext/POSIX/POSIX.xs

    private-msgid: <23338.853986967@eeyore.ibcinc.com>

 OTHER CORE CHANGES

Subject: Make PERL5LIB and -I work like C<use lib>
Date: Thu, 23 Jan 1997 15:23:27 +0000
From: Tim Bunce <Tim.Bunce@ig.co.uk>
Files: lib/lib.pm perl.c

    private-msgid: <9701231523.AA26613@toad.ig.co.uk>

Subject: Fix /\G.a/
From: Chip Salzenberg <chip@atlantic.net>
Files: regcomp.c regcomp.h regexec.c regexp.h toke.c

Subject: Extend stack in pp_undef (!)
From: Chip Salzenberg <chip@atlantic.net>
Files: pp.c

Subject: Allow for sub to be redefined while executing
From: Chip Salzenberg <chip@atlantic.net>
Files: cop.h pp_hot.c t/op/misc.t

Subject: Eliminate redundant flag CVf_FORMAT
From: Chip Salzenberg <chip@atlantic.net>
Files: cv.h op.c perl.c perly.c perly.y proto.h sv.c toke.c

Subject: Generate IVs when possible in abs() and int()
From: Chip Salzenberg <chip@atlantic.net>
Files: pp.c

Subject: Efficiency patchlet for pp_aassign()
Date: Mon, 20 Jan 1997 22:05:39 -0500 (EST)
From: Ilya Zakharevich <ilya@math.ohio-state.edu>
Files: pp_hot.c
Msg-ID: <199701210305.WAA05451@monk.mps.ohio-state.edu>

    (applied based on p5p patch as commit 7e42bd57a6867e174bc3bc555c3268b485940a98)

Subject: Remove "suidperl security patch" message
From: Chip Salzenberg <chip@atlantic.net>
Files: perl.c

 TESTS

Subject: Fix tests of $^X and $0 to work with QNX
From: Chip Salzenberg <chip@atlantic.net>
Files: t/lib/io_pipe.t t/lib/open2.t t/lib/open3.t t/op/magic.t

Subject: Patch tests for systems without fork()
Date: Thu, 23 Jan 1997 23:51:28 +0100
From: "Norbert Pueschel" <pueschel@imsdd.meb.uni-bonn.de>
Files: t/io/pipe.t t/lib/filehand.t t/lib/io_pipe.t t/lib/io_sock.t t/lib/open2.t t/lib/open3.t t/op/fork.t

    private-msgid: <77724697@Armageddon.meb.uni-bonn.de>

Subject: Test patches for OS/2
Date: Thu, 16 Jan 1997 23:48:18 -0500 (EST)
From: Ilya Zakharevich <ilya@math.ohio-state.edu>
Files: os2/OS2/ExtAttr/t/os2_ea.t os2/OS2/PrfDB/t/os2_prfdb.t os2/OS2/REXX/t/rx_cmprt.t os2/OS2/REXX/t/rx_dllld.t os2/OS2/REXX/t/rx_objcall.t os2/OS2/REXX/t/rx_sql.test os2/OS2/REXX/t/rx_tiesql.test os2/OS2/REXX/t/rx_tievar.t os2/OS2/REXX/t/rx_tieydb.t os2/OS2/REXX/t/rx_varset.t os2/OS2/REXX/t/rx_vrexx.t t/README t/cmd/while.t t/comp/colon.t t/comp/multiline.t t/io/argv.t t/lib/anydbm.t t/lib/gdbm.t t/lib/ndbm.t t/lib/odbm.t t/lib/sdbm.t t/op/cmp.t t/op/magic.t
Msg-ID: <199701170448.XAA28948@monk.mps.ohio-state.edu>

    (applied based on p5p patch as commit bbad36071d5a6d4be3588f0f10c88247439076d8)

 UTILITIES

Subject: Translate \200 to &#200; in pod2html
From: Chip Salzenberg <chip@atlantic.net>
Files: pod/pod2html.PL

Subject: VMS patches: '.com' extension on scripts
Date: Fri, 24 Jan 1997 18:42:29 -0500 (EST)
From: Charles Bailey <bailey@HMIVAX.HUMGEN.UPENN.EDU>
Files: pod/checkpods.PL pod/pod2html.PL pod/pod2latex.PL pod/pod2man.PL pod/pod2text.PL utils/c2ph.PL utils/h2ph.PL utils/h2xs.PL utils/perlbug.PL utils/perldoc.PL utils/pl2pm.PL utils/splain.PL vms/Makefile vms/descrip.mms x2p/find2perl.PL x2p/s2p.PL

    private-msgid: <01IELNPDLYJM003E7J@hmivax.humgen.upenn.edu>

1 files changed, 83 insertions, 24 deletions

diff --git a/lib/overload.pm b/lib/overload.pm
index 049545995c..0eb9702f82 100644
--- a/lib/overload.pm
+++ b/lib/overload.pm
@@ -149,9 +149,10 @@ the "class" C<Number> (or one of its base classes)
 for the assignment form C<*=> of multiplication.  
 
 Arguments of this directive come in (key, value) pairs.  Legal values
-are values legal inside a C<&{ ... }> call, so the name of a subroutine,
-a reference to a subroutine, or an anonymous subroutine will all work.
-Legal keys are listed below.
+are values legal inside a C<&{ ... }> call, so the name of a
+subroutine, a reference to a subroutine, or an anonymous subroutine
+will all work.  Note that values specified as strings are
+interpreted as methods, not subroutines.  Legal keys are listed below.
 
 The subroutine C<add> will be called to execute C<$a+$b> if $a
 is a reference to an object blessed into the package C<Number>, or if $a is
@@ -161,6 +162,10 @@ C<$a+=7>, or C<$a++>.  See L<MAGIC AUTOGENERATION>.  (Mathemagical
 methods refer to methods triggered by an overloaded mathematical
 operator.)
 
+Since overloading respects inheritance via the @ISA hierarchy, the
+above declaration would also trigger overloading of C<+> and C<*=> in
+all the packages which inherit from C<Number>.
+
 =head2 Calling Conventions for Binary Operations
 
 The functions specified in the C<use overload ...> directive are called
@@ -269,12 +274,46 @@ see L<SPECIAL SYMBOLS FOR C<use overload>>.
 
 See L<"Fallback"> for an explanation of when a missing method can be autogenerated.
 
+=head2 Inheritance and overloading
+
+Inheritance interacts with overloading in two ways.
+
+=over
+
+=item Strings as values of C<use overload> directive
+
+If C<value> in
+
+  use overload key => value;
+
+is a string, it is interpreted as a method name.
+
+=item Overloading of an operation is inherited by derived classes
+
+Any class derived from an overloaded class is also overloaded.  The
+set of overloaded methods is the union of overloaded methods of all
+the ancestors. If some method is overloaded in several ancestor, then
+which description will be used is decided by the usual inheritance
+rules:
+
+If C<A> inherits from C<B> and C<C> (in this order), C<B> overloads
+C<+> with C<\&D::plus_sub>, and C<C> overloads C<+> by C<"plus_meth">,
+then the subroutine C<D::plus_sub> will be called to implement
+operation C<+> for an object in package C<A>.
+
+=back
+
+Note that since the value of the C<fallback> key is not a subroutine,
+its inheritance is not governed by the above rules.  In the current
+implementation, the value of C<fallback> in the first overloaded
+ancestor is used, but this is accidental and subject to change.
+
 =head1 SPECIAL SYMBOLS FOR C<use overload>
 
 Three keys are recognized by Perl that are not covered by the above
 description.
 
-=head2  Last Resort
+=head2 Last Resort
 
 C<"nomethod"> should be followed by a reference to a function of four
 parameters.  If defined, it is called when the overloading mechanism
@@ -321,6 +360,9 @@ C<"nomethod"> value, and if this is missing, raises an exception.
 
 =back
 
+B<Note.> C<"fallback"> inheritance via @ISA is not carved in stone
+yet, see L<"Inheritance and overloading">.
+
 =head2 Copy Constructor
 
 The value for C<"="> is a reference to a function with three
@@ -484,31 +526,40 @@ Returns C<undef> or a reference to the method that implements C<op>.
 
 What follows is subject to change RSN.
 
-The table of methods for all operations is cached as magic in the
-symbol table hash for the package.  The table is rechecked for changes due to
-C<use overload>, C<no overload>, and @ISA only during
-C<bless>ing; so if they are changed dynamically, you'll need an
-additional fake C<bless>ing to update the table.
-
-(Every SVish thing has a magic queue, and magic is an entry in that queue.
-This is how a single variable may participate in multiple forms of magic
-simultaneously.  For instance, environment variables regularly have two
-forms at once: their %ENV magic and their taint magic.)
+The table of methods for all operations is cached in magic for the
+symbol table hash for the package.  The cache is invalidated during
+processing of C<use overload>, C<no overload>, new function
+definitions, and changes in @ISA. However, this invalidation remains
+unprocessed until the next C<bless>ing into the package. Hence if you
+want to change overloading structure dynamically, you'll need an
+additional (fake) C<bless>ing to update the table.
+
+(Every SVish thing has a magic queue, and magic is an entry in that
+queue.  This is how a single variable may participate in multiple
+forms of magic simultaneously.  For instance, environment variables
+regularly have two forms at once: their %ENV magic and their taint
+magic. However, the magic which implements overloading is applied to
+the stashes, which are rarely used directly, thus should not slow down
+Perl.)
 
 If an object belongs to a package using overload, it carries a special
 flag.  Thus the only speed penalty during arithmetic operations without
 overloading is the checking of this flag.
 
-In fact, if C<use overload> is not present, there is almost no overhead for
-overloadable operations, so most programs should not suffer measurable
-performance penalties.  A considerable effort was made to minimize the overhead
-when overload is used and the current operation is overloadable but
-the arguments in question do not belong to packages using overload.  When
-in doubt, test your speed with C<use overload> and without it.  So far there
-have been no reports of substantial speed degradation if Perl is compiled
-with optimization turned on.
-
-There is no size penalty for data if overload is not used. 
+In fact, if C<use overload> is not present, there is almost no overhead
+for overloadable operations, so most programs should not suffer
+measurable performance penalties.  A considerable effort was made to
+minimize the overhead when overload is used in some package, but the
+arguments in question do not belong to packages using overload.  When
+in doubt, test your speed with C<use overload> and without it.  So far
+there have been no reports of substantial speed degradation if Perl is
+compiled with optimization turned on.
+
+There is no size penalty for data if overload is not used. The only
+size penalty if overload is used in some package is that I<all> the
+packages acquire a magic during the next C<bless>ing into the
+package. This magic is three-words-long for packages without
+overloading, and carries the cache tabel if the package is overloaded.
 
 Copying (C<$a=$b>) is shallow; however, a one-level-deep copying is 
 carried out before any operation that can imply an assignment to the
@@ -527,6 +578,14 @@ Ilya Zakharevich E<lt>F<ilya@math.mps.ohio-state.edu>E<gt>.
 When Perl is run with the B<-Do> switch or its equivalent, overloading
 induces diagnostic messages.
 
+Using the C<m> command of Perl debugger (see L<perldebug>) one can
+deduce which operations are overloaded (and which ancestor triggers
+this overloading). Say, if C<eq> is overloaded, then the method C<(eq>
+is shown by debugger. The method C<()> corresponds to the C<fallback>
+key (in fact a presence of this method shows that this package has
+overloading enabled, and it is what is used by the C<Overloaded>
+function).
+
 =head1 BUGS
 
 Because it is used for overloading, the per-package associative array