path: root/os2/Changes

after 5.003_05:
	PERLLIB_PREFIX was not active if it matches an element of @INC
		as a whole.
	Do not need PERL_SBRK if crtdll-revision is >= 50.
	Use -Zsmall-conv if crtdll-revision is >= 50 (in static perl!).
:7: warning: #warning <dirent.h> requires <sys/types.h>
	We compile miniperl static. It cannot fork, thus there may be
		problems with pipes (since HAS_FORK is in
		place). Pipes are required by makemaker.
	We compile perl___.exe A.OUT and dynamic. It should be able to
		fork.
	If we can fork, we my_popen by popen unless "-|". Thus we
		write a cooky "-1" into the pid array to indicate
		this.
	Apparently we can fork, and we can load dynamic extensions
		now, though probably not simultaneously.
	*DB tests corrected for OS/2 one-user stat[2].
	/bin/sh is intercepted and replaced by SH_PATH.
	Note that having '\\' in the command line of one-arg `system'
		would trigger call via shell.
	Segfault with system {'ls'} 'blah'; corrected.
	Documentation of OS/2-different features added to main PODs.
	New buitins in Cwd::

		Cwd::current_drive
		Cwd::sys_chdir		- leaves drive as it is.
		Cwd::change_drive
		Cwd::sys_is_absolute	- has drive letter and is_rooted
		Cwd::sys_is_rooted	- has leading [/\\] (maybe
					  after a drive)
		Cwd::sys_is_relative	- changes with current dir
		Cwd::sys_cwd		- Interface to cwd from EMX.
		Cwd::sys_abspath(name, dir)	
					- Really really odious
					  function. Returns absolute
					  name of file which would 
					  have 'name' if CWD were 'dir'.
					Dir defaults to the current dir.
		Cwd::extLibpath [type]	- Get/set current value of extended
		Cwd::extLibpath_set	- library search path.
			path [type]
					The optional last argument redirects
					   to END-path if true,
					   default is to search BEGIN-path.
		(Note that some of these may be moved to different
		  libraries - eventually).
	Executables: 
		perl - can fork, can dynalink (but not simultaneously)
		perl_ - can fork, cannot dynalink
		perl__ - same as perl___, but PM.
		perl___ - cannot fork, can dynalink.
	The build of the first one - perl - is rather convoluted, and
	  requires a build of miniperl_.

after 5.003_07:
	custom tmpfile and tmpname which may use $TMP, $TEMP.
	all the calls to OS/2 API wrapped so that it is safe to use
		them under DOS (may die(), though).
	Tested that popen works under DOS with modified PDKSH and RSX.
	File::Copy works under DOS.
	MakeMaker modified to work under DOS (perlmain.c.tmp and sh -c true).

after 5.003_08:
	OS2::PrfDB exports symbols as documented;
	should work on OS/2 2.1 again.
	uses reliable signals when spawing.
	do not use popen() any more - no intermediate shell unless needed.

after 5.003_11:
	Functions emx_{malloc,realloc,calloc,free} are exported from DLL.
	get_sysinfo() bugs corrected (flags were not used and wrongly defined).

after 5.003_20:
	_isterm is substituted instead of isatty, s?random instead of srand.
	`register' disabled if -DDEBUGGING and not AOUT build: stupid SD386.
	3-argument select() was stomping over memory.

after 5.003_21:
	Can start scripts by executing 'dir/script' and
	'script.sh'. Form without extension will call shell only if
	the specified file exists (will not look on path) (to prohibit
	trying to run shell commands directly). - Needed by magic.t.

after 5.003_27:
	ALTERNATE_SHEBANG="extproc " supported, thus options on this
	line are processed (possibly twice). -S is made legal on such
	a line. This -S -x is not needed any more.
	perl.dll may be used from non-EMX programs (via PERL_SYS_INIT
	- the caller should have valid variable "env" with
	environment). Known problems: $$ does not work - is 0, waitpid
	returns immediately, thus Perl cannot wait for completion of
	started programs.

after 5.004_01:
	flock emulation added (disable by setting env PERL_USE_FLOCK=0),
		thanks to Rocco Caputo;
	RSX bug with missing waitpid circumvented;
	-S bug with full path with \ corrected.

before 5.004_02:
	-S switch to perl enables a search with additional extensions 
	.cmd, .btm, .bat, .pl as well.  This means that if you have
	mycmd.pl or mycmd.bat on PATH, 
		perl -S mycmd
	will work.  Perl will also look in the current directory first.
	Moreover, a bug with \; in PATH being non-separator is fixed.

after 5.004_03:
	$^E tracks calls to CRT now.  (May break if Perl masks some
	changes to errno?)
	$0 may be edited to longer lengths (at least under OS/2).
	OS2::REXX->loads looks in the OS/2-ish fashion too.

after 5.004_04:
	Default perl.exe was built with a shorter stack than expected.
	Strip extensions DLLs too (unless debugging build).
	./os2.c being RO could stop cp.
	When starting scripts, Perl will find them on path (using the same
	  extensions as for -S command-line switch).  If it finds magic
	  `extproc ' or `#!' cookies, it will start the scripts directly.
	May use `cmd /c more <' as a pager.
	If a program could not be started, this might have been hidden.
	End of pipe was closed twice when `open'ing a pipeline.

after 5.004_53:
	Minimal thread support added.  One needs to manually move pthread.h

after 5.004_64:
	Make DLL names different if thread-enabled.
	Emit more informative internal DLL descriptions.

5.004_72:
	Updated OS2::Process (v0.2) included.
	
after 5.004_73:
	Fixed a bug with argv not NULL-terminated when starting scripts.
	Support all the forms of starting scripts.
	Support killing a child when receiving a signal during system()
	(in two stage, on first send the same signal, on the next
	send SIGKILL).
	Add the same logic for scripts as in pdksh, including 
		stripping the path from #! line if needed, 
		calling EXECSHELL or COMSPEC for magic-less scripts;
	Now pdksh is called only if one-arg system()/friends contains
	metachars, or if magic-line asks for sh, or there is no magic
	line and EXECSHELL is set to sh.
	Shell is supplied the original command line if possible.

after 5.005_02:
	Can start PM programs from non-PM sessions by plain system()
		and friends.  Can start DOS/Win programs.  Can start
		fullscreen programs from non-fullscreen sessions too.
	In fact system(P_PM,...) was broken.
	We mangle the name of perl*.DLL, to allow coexistence of different
		versions of Perl executables on the system.  Mangling of
		names of extension DLL is also changed, thus running two
		different versions of the executable with loaded
		extensions should not lead to conflicts (since 
		extension-full-name and Perl-version mangling work in the 
		same set ot 576 possible keys, this may lead to clashes).
	$^E was reset on the second read, and contained ".\r\n" at the end.

after 5.005_53:
	Would segfault system()ing non-existing program;
	AOUT build was hosed;
	warning-test for getpriority() might lock the system hard on 
		pre-fixpak22 configuration (calling getpriority() on 
		non-existing process triggers a system-wide bug).


	PrfDB was using a bug in processing XSUBs returning U32.

	Variable $OS2::emx_rev implemented (string and numeric values
		are the same as C variables _emx_rev and _emx_vprt).
	Variable $OS2::emx_env implemented (same as C variable _emx_env).
	Variable $OS2::os_ver implemented (_osmajor + 0.001 * _osminor).

	Improved centralized management of HAB and HMQ.  To get Perl's
		HAB, call perl_hab_GET().  (After the initial call one
		can use Perl_hab instead.)  To require Perl's HMQ,
		call perl_hmq_GET(), to release it call perl_hmq_UNSET(),
		to obtain it between these calls use Perl_hmq.
	HMQ management is refcounted, and the program will morph
		itself into/from PM if required.
	If perl.h cannot be included, hab may be obtained by Perl_hab_GET().

	New function OS2::Error(do_harderror,do_exception).  Returns
		undef if it was not called yet, otherwise bit 1 is
		set if on previous call do_harderror was enabled, bit
		2 is set if if on previous call do_exception was enabled.
	This function enables/disables error popups associated with 
		hardware errors (Disk not ready etc.) and software exceptions.

	New function OS2::Errors2Drive(drive).  Returns undef if it was 
		not called yet, otherwise return false if Errors were
		not requested to be written to a hard drive, or the
		drive letter if this was requested.
	This function may redirect error popups associated with 
		hardware errors (Disk not ready etc.) and software exceptions
		to the file POPUPLOG.OS2 at the root directory of the
		specified drive.  Overrides OS2::Error() specified by 
		individual programs.  Given argument undef will
		disable redirection.  Has global effect, persists
		after the application exits.

	New function OS2::SysInfo().  Returns a hash with system information.
		The keys of the hash are

		MAX_PATH_LENGTH, MAX_TEXT_SESSIONS, MAX_PM_SESSIONS,
		MAX_VDM_SESSIONS, BOOT_DRIVE, DYN_PRI_VARIATION,
		MAX_WAIT, MIN_SLICE, MAX_SLICE, PAGE_SIZE,
		VERSION_MAJOR, VERSION_MINOR, VERSION_REVISION,
		MS_COUNT, TIME_LOW, TIME_HIGH, TOTPHYSMEM, TOTRESMEM,
		TOTAVAILMEM, MAXPRMEM, MAXSHMEM, TIMER_INTERVAL,
		MAX_COMP_LENGTH, FOREGROUND_FS_SESSION,
		FOREGROUND_PROCESS

	New function OS2::BootDrive(force).  Returns a letter without colon.

	New functions OS2::MorphPM(serve)/OS2::UnMorphPM(serve).  Transforms
		the current application into a PM application and back.
		The argument true means that a real message loop is
		going to be performed.
	OS2::MorphPM() returns the PM message queue handle as an integer.

	New function OS2::Serve_Messages(force).  Fake on-demand
		retrieval of outstanding PM messages.  If force is false,
		will not dispatch messages if a real message loop is known to
		be present.  Returns number of messages retrieved.
	Dies with "QUITing..." if WM_QUIT message is obtained.

	New function OS2::Process_Messages(force [, cnt]).  Retrieval
		of PM messages until window creation/destruction.  
		If force is false, will not dispatch messages 
		if a real message loop is known to be present.  
		Returns change in number of windows.  If cnt is given,
		it is incremented by the number of messages retrieved.
	Dies with "QUITing..." if WM_QUIT message is obtained.

after 5.005_54:
 	Opening pipes from/to processes could fail if (un)appropriate
 	combination of STDIN/STDOUT was closed.
 
 	If the only shell-metachars of a command are ' 2>&1' at the
 	end of a command, it is executed without calling the external shell.

after 5.005_57:
	Make UDP sockets return correct caller address (OS2 API bug);
	Enable TCPIPV4 defines (works with Warp 3 IAK too?!);
	Force Unix-domain sockets to start with "/socket", convert
	  '/' to '\' in the calls;
	Make C<system 1, $cmd> to treat $cmd as in C<system $cmd>;
	Autopatch Configure;
	Find name and location of g[nu]patch.exe;
	Autocopy perl????.dll to t/ when testing;

after 5.005_62:
	Extract a lightweight DLL access module OS2::DLL from OS2::REXX
	   which would not load REXX runtime system;
	Allow compile with os2.h which loads os2tk.h instead of os2emx.h;
	Put the version of EMX CRTL into -D define;
	Use _setsyserror() to store last error of OS/2 API for $^E;
	New macro PERL_SYS_INIT3(argvp, argcp, envp);
	Make Dynaloader return info on the failing module after failed dl_open();
	OS2::REXX test were done for interactive testing (were writing
	  "ok" to stderr);
	system() and friends return -1 on failure (was 0xFF00);
	Put the full name of executable into $^X
	  (alas, uppercased - but with /);
	t/io/fs.t was failing on HPFS386;
	Remove extra ';' from defines for MQ operations.

pre 5.6.1:
	Resolved: "Bad free()" messages (e.g., from DB_File) with -Zomf build.
	   The reason was: when an extension DLL was linked, the order of
	   libraries was similar to this:
		f1.obj f2.obj libperl.lib -llibr1 -llibr2
	   (with C RTL implicitly after this).  When libperl.lib overrides
	   some C RTL functions, they are correctly resolved when mentioned
	   in f1.obj and f2.obj.  However, the resolution for libr1.lib and
	   libr2.lib is implementation-dependent.

	   With -Zomf linking the symbols are resolved for libr1.lib and
	   libr2.lib *only if* they reside in .obj-file-sections of libperl.lib
	   which were already "picked up" for symbols in f1.obj f2.obj.
	   However, libperl.lib is an import library for a .DLL, so *each
	   symbol in libperl.lib sits in its own pseudo-section*!

	   Corollary: only those symbol from libperl.lib which were already
	   mentioned in f1.obj f2.obj would be used for libr1.lib and
	   libr2.lib.  Example: if f1.obj f2.obj do not mention calloc() but
	   libr1.lib and libr2.lib do, then .lib's will get calloc() of C RTL,
	   not one of libperl.lib.

	   Solution: create a small duplicate of libperl.lib with overriding
	   symbols only.  Put it *after* -llibr1 -llibr2 on the link line.
	   Map strdup() and putenv() to Perl_strdup() and Perl_putenv()
	   inside this library.

	Resolved: rmdir() and mkdir() do not accept trailing slashes.
	   Wrappers are implemented.
	Resolved: when loading modules, FP mask may be erroneously changed by
	   _DLLInitTerm() (e.g., TCP32IP).
		Solutions: a) dlopen() saves/restores the FP mask.
			   b) When starting, reset FP mask to a sane value
				(if the DLL was compile-time linked).
	New functions in package OS2:
		unsigned _control87(unsigned new,unsigned mask)	# as in EMX
		unsigned get_control87()
		# with default values good for handling exception mask:
		unsigned set_control87_em(new=MCW_EM,mask=MCW_EM)
	    Needed to guard against other situations when the FP mask is
	    stomped upon.  Apparently, IBM used a compiler (for some period
	    of time around '95?) which changes FP mask right and left...
	Resolved: $^X was always uppercased (cosmetic).  Solution:
	    use argv[0] if it differs from what the OS returns only in case.
	Resolved: when creating PM message queues, WinCancelShutdown() was
	    not called even if the application said that it would not serve
	    messages in this queue.  Could result in PM refusing to shutdown.

	    Solution: resolve WinCancelShutdown at run time, keep the refcount
	    of who is going to serve the queue.
	Resolved: Perl_Deregister_MQ() segfaulted (pid/tid not initialized).
	Resolved: FillWinError() would not fetch the error.
	    Solution: resolve WinGetLastError at run time, call it.
	Resolved: OS2::REXX would ignore arguments given to a Perl function
	    imported into the REXX compartment via REXX_eval_with().
	Resolved: OS2::REXX would treat arguments given to a Perl function
	    imported into the REXX compartment via _register() as ASCIIZ
	    strings inside of binary strings.
	Resolved: OS2::REXX did not document _register().
	Resolved: OS2::REXX would not report the error to REXX if an error
	    condition appeared during a call to Perl function from REXX
	    compartment.  As a result, the return string was not initialized.
	A complete example of a mini-application added to OS2::REXX.
	README.os2 updated to reflect the current state of Perl.

pre 5.7.2:
	aout build: kid bootstrap_* were not associated with XS.
	bldlevel did not contain enough info.
	extLibpath* was failing on the call of the second type.
	Configure defines flushNULL now (EMX -Zomf bug broke autodetection).
	Configure did not find SIGBREAK.
	extLibpath supports LIBSTRICT, better error detection.
	crypt() used if present in -lcrypt or -lufc.
	dumb getpw*(), getgr*() etc. supported; as in EMX, but if no
	    $ENV{PW_PASSWD}, the passwd field contains a string which
	    cannot be returned by crypt() (for security reasons).
	The unwound recursion in detecting executable by script was
	    using static buffers.  Thus system('pod2text') would fail if the
	    current directory contained an empty file named 'perl'.
	Put ordinals in the base DLL.
	Enable EXE-compression.
	    Load time (ms):  Without /e:2: 70.6; With /e:2: 75.3; Lxlite: 62.8
	    Size drops from 750K to 627K, with lxlite to 515K.
	    lxlite /c:max gives 488K, but dumps core in t/TEST
	os2ish.h defines SYSLOG constants ==> Sys::Syslog works.
	Corrected warnings related to OS/2 code.
	    At one place = was put instead of ==.
	Setting $^E should work.
	Force "SYS0dddd=0xbar: " to error messages and to dlerror().
	    ($^E == 2 printed SYS0002 itself, but 110 did not.)
	$OS2::nsyserror=0 switches off forcing SYSdddd on $^E.
	perl_.exe does not require PM dlls any more (symbols resolved at
	    runtime on the as needed basis).
	OS2::Process:
	    get/set: term size; codepages; screen's cursor; screen's contents
	    reliable session name setting;
	    process's parent pid, and the session id;
	    switching to and enumeration of sessions
	    window hierarchy inspection
	    post a message to a window
	More robust getpriority() on older Warps.

	New C APIs for runtime loading of entry points from DLLs
	(useful for entry points not present on older versions of
	OS/2, or with DLLs not present on floppy-boot stripped down
	setups): CallORD(), DeclFuncByORD(), DeclVoidFuncByORD(),
	DeclOSFuncByORD(), DeclWinFuncByORD(), AssignFuncPByORD().

pre 5.7.3:
	Testing with PERL_TEST_NOVREXX=1 in environment makes tests
	noninteractive (VREXX test requires pressing a button on a dialog).

	New (ugly and voodooish) hack to work around a bug in EMX
	runtime architecture:

	  EMX.DLL is *not* initialized from its _DLL_InitTerm()
	  routine, but the initialization is postponed until
	  immediately before main() is called by the principal
	  executable (may be the initialization also happens during
	  InitTerm of -Zso -Zsys DLLs?).  The only reason I can see is
	  to postpone the initialization until the "layout" structure
	  is available, so the type of the executable is known.
	  [Instead, one should have broken the initialization into two
	  steps, with no-layout-known initialization ASAP, and the
	  finishing touch done when "layout" is known.]

	  It is due to this hack that -Zsys, -Zso etc. are needed so
	  often.

	  If during initialization of the Perl runtime environment we
	  discover that EMX environment is not set up completely, this
	  can be because of either our DLL being called from an
	  uncompatible flavor of EMX executable, or from an
	  unrelated-to-EMX.DLL (e.g., -Zsys or compiled with a
	  different compiler) executable.  In the first case only the
	  CRTL is not completely initialized, in the other case
	  EMX.DLL may be not initialized too.

	  We detect which of these two situations takes place, then
	  explicitly call the initialization entry points of EMX.DLL
	  and of CRT.  The large caveat is that the init-entry point
	  of EMX.DLL also moves the stack pointer (another defect of
	  EMX architecture, the init() and
	  set_exception_handlers_on_stack() entry points should have
	  been separated).  Thus we need some inline-assembler to
	  compensate for this, and need to remove the installed
	  exception handler - it is useless anyway, since exception
	  handlers need to be on the stack.  [This one is on the
	  stack, but will be overwritten on exit from the function.]

	  We also install an extra hack to run our atexit() handlers
	  on termination of the process (since the principal
	  executable does not know about *this* CRTL, we need to do it
	  ourselves - and longjmp() out of the chain of exception
	  handlers at a proper moment :-().

	The net result: Perl DLL can be now used with an arbitrary
	application.  PERLREXX DLL is provided which makes Perl usable
	from any REXX-enabled application.

	New test targets added to test how well Perl DLL runs with
	different flavors of executables (see all_harness etc).  To
	avoid waiting for the user button press, run with env
	PERL_TEST_NOVREXX=1.

	Another hack: on init of Perl runtime environment, the
	executable is tested for being an aout EMX executable.  The
	test is the same done by gdb, so although this test is very
	voodoo, it should be pretty robust (the beginning of the
	executable code - at 0x10000 - is tested for a known bit
	pattern).  The result is used to set $OS2::can_fork, which is
	eventually used to set $Config::Config{can_fork}.

	REXX::eval_REXX() made reenterable.  ADDRESS PERLEVAL
	available for the run REXX code.  PERLLASTERROR available.

	A .map file is created for the .dll.  Now easier to debug the
	failures which do not happen with a debugging executable.

	Duplicate libperl.lib as perl.lib etc. to make Embed happier.

	File::Spec better adjusted to OS/2 (still does not support aa:/dir/).

	New module OS::Process::Const with necessary constants for the
	Perl calls which mimic OS/2 API calls.

After @14577:
	$Config{pager} better (but needs work in the binary installer!).

	New API: OS2::DLLname([type], [\&sub])

	New OS2::Process APIs:

		 process_hwnd winTitle_set winTitle swTitle_set bothTitle_set
                 hWindowPos hWindowPos_set DesktopWindow
                 ActiveWindow_set
                 EnableWindow EnableWindowUpdate IsWindowEnabled
                 IsWindowVisible IsWindowShowing WindowPtr WindowULong
                 WindowUShort SetWindowBits SetWindowPtr
                 SetWindowULong
                 SetWindowUShort MPFROMSHORT MPVOID MPFROMCHAR
                 MPFROM2SHORT
                 MPFROMSH2CH MPFROMLONG

	OS::Process::Const symbols exportable from OS::Process too.

	OS::Process: prototypes on subroutines which do not naturally
	take "vectors" as arguments (not backwards compatible!).

	New C API: SaveCroakWinError(), WinError_2_Perl_rc,
	DeclWinFuncByORD_CACHE(), DeclWinFuncByORD_CACHE_survive(),
	DeclWinFuncByORD_CACHE_resetError_survive(),
	DeclWinFunc_CACHE(), DeclWinFunc_CACHE_resetError(),
	DeclWinFunc_CACHE_survive(),
	DeclWinFunc_CACHE_resetError_survive(); many new OS2 entry
	points conveniently available via wrappers which will do the
	necessary run-time dynalinking.

After @15047:
	makes PerlIO preserve the binary/text mode of filehandles
	chosen by CRT library.  (However, TTY handles still are not
	clean, since switching them to TERMIO mode and back changes
	the NL translation law at runtime, and PerlIO level does not
	know this.)

After @18156:
	mkdir() rmdir() tolerate trailing slashes.
	"localized" morphing to PM when already morphed would unmorph at end.
	Convert \n to \r\n in REXX commands (Classic REXX would allow \r and
		\r\n, but not \n as line-ends).

After @19053:
	Better detection of OS/2 in Configure scripts (if c:/ is not readable).
	Better Configure support for \\ inside cpp-emited # lineno "filename".
	Export pthread-support functions from threaded DLL.
	[older change] If perl5.def file is present, the new perl5.def has
		compatible ordinals.
	OS/2 code compiles with threads enabled; much more robust pthreads
		emulation (but some statics still present); survives fork().
	New attributes supported with [f]stat() and chmod()
		  archived is 0x1000000 =  0100000000
		  hidden   is 0x2000000 =  0200000000
		  system   is 0x4000000 =  0400000000
		If extra flag 0x8000000 = 01000000000 is missing during
		chmod(), these 3 flags are ignored; this extra flag
		is set in the result of stat() [this provides backward
		compatibility, as well as transparency of stat()/
		chmod() supporting DOSISH].
	OS/2-specific modules use XSLoader now.
	Remove DLLs manually after failing build (link386 would not?!).
	Special-case stat()ing "/dev/nul" and "/dev/null" too.
	Update dlopen() and friends: preserve i387 flags, better error messages,
		support name==NULL (load for "this" DLL);
	OS2::DLL does not eval() generated functions, uses closes instead;
		new method wrapper_REXX() for DLL objects.

After @19774:
	Use common typemap for OS2:: modules.
	New test file os2/perlrexx.cmd (should be run manually; does not it
		exit too early???).
	Export fork_with_resources(), croak_with_os2error() from DLL.
	usleep() availability put in %Config{}.
	Combine most (but not all!) statics into one struct.
	New load-on-demand C functions 
		Dos32QueryHeaderInfo
		DosTmrQueryFreq
		DosTmrQueryTime
		WinQueryActiveDesktopPathname
		WinInvalidateRect
		WinCreateFrameControl
		WinQueryClipbrdFmtInfo
		WinQueryClipbrdOwner
		WinQueryClipbrdViewer
		WinQueryClipbrdData
		WinOpenClipbrd
		WinCloseClipbrd
		WinSetClipbrdData
		WinSetClipbrdOwner
		WinSetClipbrdViewer
		WinEnumClipbrdFmts 
		WinEmptyClipbrd
		WinAddAtom
		WinFindAtom
		WinDeleteAtom
		WinQueryAtomUsage
		WinQueryAtomName
		WinQueryAtomLength
		WinQuerySystemAtomTable
		WinCreateAtomTable
		WinDestroyAtomTable
		WinOpenWindowDC
		DevOpenDC
		DevQueryCaps
		DevCloseDC
		WinMessageBox
		WinMessageBox2
		WinQuerySysValue
		WinSetSysValue
		WinAlarm
		WinFlashWindow
		WinLoadPointer
		WinQuerySysPointer	
	Check "\\SEM32\\PMDRAG.SEM" before loading PM-specific DLLs.
	Handling of system {realname} was not correct in presence of
		exe-type deduction, #!-emulation etc.
	Use optimized PUSHTARG etc. XSUB convention.
	$^E stringification contains PMERR_INVALID_HWND, PMERR_INVALID_HMQ, 
		PMERR_CALL_FROM_WRONG_THREAD, PMERR_NO_MSG_QUEUE,
		PMERR_NOT_IN_A_PM_SESSION if these errors are not in .MSG file
		(at least on Warp3fp42).
	PERLLIB_PREFIX augmented by PERLLIB_582_PREFIX, PERLLIB_58_PREFIX,
		PERLLIB_5_PREFIX (example for 5.8.2, the first one present is
		considered).
	New flag bit 0x2 for OS2::MorphPM(): immediately unmorph after creation
		of message queue.
	(De)Registring MQ preserves i386 flags.
	When die()ing inside OS2:: API, include $^E in the message.
	New function OS2::Timer(): returns Tmr-timer ticks (about 1MHz) since
		start of OS/2, converted to number of seconds (keep in mind
		that this timer uses a different crystal than the real-time
		clock; thus these values have only weak relationship to the
		wall clock time; behaviour with APM on is not defined).
	New function OS2::DevCap() [XXX Wrong usage message!!!]
		Usage: OS2::DevCap([WHAT, [HOW=0]]); the default for WHAT is
		the memory device context, WHAT should be a device context
		(as integer) if HOW==0 and a window handle (as integer) if
		HOW==1.  Returns a hash with keys
			FAMILY IO_CAPS TECHNOLOGY DRIVER_VERSION WIDTH HEIGHT
			WIDTH_IN_CHARS HEIGHT_IN_CHARS HORIZONTAL_RESOLUTION
			VERTICAL_RESOLUTION CHAR_WIDTH CHAR_HEIGHT
			SMALL_CHAR_WIDTH SMALL_CHAR_HEIGHT COLORS COLOR_PLANES
			COLOR_BITCOUNT COLOR_TABLE_SUPPORT MOUSE_BUTTONS
			FOREGROUND_MIX_SUPPORT BACKGROUND_MIX_SUPPORT
			VIO_LOADABLE_FONTS WINDOW_BYTE_ALIGNMENT BITMAP_FORMATS
			RASTER_CAPS MARKER_HEIGHT MARKER_WIDTH DEVICE_FONTS
			GRAPHICS_SUBSET GRAPHICS_VERSION GRAPHICS_VECTOR_SUBSET
			DEVICE_WINDOWING ADDITIONAL_GRAPHICS PHYS_COLORS
			COLOR_INDEX GRAPHICS_CHAR_WIDTH GRAPHICS_CHAR_HEIGHT
			HORIZONTAL_FONT_RES VERTICAL_FONT_RES DEVICE_FONT_SIM
			LINEWIDTH_THICK DEVICE_POLYSET_POINTS
	New function OS2::SysValues(which = -1, hwndDesktop = HWND_DESKTOP).
		If which != -1, returns the corresponding SysValue.  Otherwise
		returns a hash with keys:
			SWAPBUTTON DBLCLKTIME CXDBLCLK CYDBLCLK
			CXSIZEBORDER CYSIZEBORDER ALARM 7 8 CURSORRATE
			FIRSTSCROLLRATE SCROLLRATE NUMBEREDLISTS WARNINGFREQ
			NOTEFREQ ERRORFREQ WARNINGDURATION NOTEDURATION
			ERRORDURATION 19 CXSCREEN CYSCREEN CXVSCROLL CYHSCROLL
			CYVSCROLLARROW CXHSCROLLARROW CXBORDER CYBORDER
			CXDLGFRAME CYDLGFRAME CYTITLEBAR CYVSLIDER CXHSLIDER
			CXMINMAXBUTTON CYMINMAXBUTTON CYMENU
			CXFULLSCREEN CYFULLSCREEN CXICON CYICON
			CXPOINTER CYPOINTER DEBUG CPOINTERBUTTONS POINTERLEVEL
			CURSORLEVEL TRACKRECTLEVEL CTIMERS MOUSEPRESENT
			CXALIGN CYALIGN
			DESKTOPWORKAREAYTOP DESKTOPWORKAREAYBOTTOM
			DESKTOPWORKAREAXRIGHT DESKTOPWORKAREAXLEFT 55
			NOTRESERVED EXTRAKEYBEEP SETLIGHTS INSERTMODE 60 61 62 63
			MENUROLLDOWNDELAY MENUROLLUPDELAY ALTMNEMONIC
			TASKLISTMOUSEACCESS CXICONTEXTWIDTH CICONTEXTLINES
			CHORDTIME CXCHORD CYCHORD CXMOTIONSTART CYMOTIONSTART
			BEGINDRAG ENDDRAG SINGLESELECT OPEN CONTEXTMENU CONTEXTHELP
			TEXTEDIT BEGINSELECT ENDSELECT BEGINDRAGKB ENDDRAGKB
			SELECTKB OPENKB CONTEXTMENUKB CONTEXTHELPKB TEXTEDITKB
			BEGINSELECTKB ENDSELECTKB ANIMATION ANIMATIONSPEED
			MONOICONS KBDALTERED PRINTSCREEN		/* 97, the last one on one of the DDK header */
			LOCKSTARTINPUT DYNAMICDRAG 100 101 102 103 104 105 106 107
	New function OS2::SysValues_set(which, val, hwndDesktop = HWND_DESKTOP).
	Support new keys NUMPROCESSORS MAXHPRMEM MAXHSHMEM MAXPROCESSES
		VIRTUALADDRESSLIMIT INT10ENABLE from OS2::SysInfo(); support
		up to 10 unnamed values after the last named one.
	New function OS2::SysInfoFor(id[,count=1]). [Wrong usage message!!!]
	New function OS2::Beep(freq = 440, ms = 100).
	New flags mod_name_C_function = 0x100, mod_name_HMODULE = 0x200 in
		addition to old mod_name_handle = 0, mod_name_shortname = 1,
		mod_name_full = 2 for OS2::DLLname(flag, cv); use an address
		(as integer) or module handle instead of cv.
	New function OS2::_headerInfo(req,size[,handle,[offset]]).
	New function OS2::libPath(); returns the value of LIBPATH.
	New function OS2::mytype(which=0) to query current process type:
		0:	type immediately after startup or last fork();
		1:	type immediately after startup;
		2:	type before the first morphing;
		3:	type as set now in the header.
	New function OS2::mytype_set(type);
	New function OS2::incrMaxFHandles(delta = 0); returns updated value
		for the possible number of open file descriptors.
	Make check_emx_runtime() thread-safe.
	Fix float-to-string conversion in the range .0001..0.1 (would return
		in exponential notation, per gcvt()).
	Make fork(): a) preserve i387 flags;
		     b) preserve the dynamically loaded (system) DLLs;
		     c) preserve morphed status;
	Make sleep() work with time > 0xffffffff/1000.
	Implement usleep() via _sleep2(); make select() with num_files==0
		thread-safe (via calling DosSleep()).
	OS2::Process::Const() manages (MB|MBID|CF|CFI|SPTR)_.* constants too.
	New (exported) functions from OS2::Process (some undocumented???):
		process_codepage_set
		TopLevel
		FocusWindow_set_keep_Zorder
		ActiveDesktopPathname
		InvalidateRect
		CreateFrameControl
		ClipbrdFmtInfo
		ClipbrdOwner
		ClipbrdViewer
		ClipbrdData
		OpenClipbrd
		CloseClipbrd
		ClipbrdData_set
		ClipbrdOwner_set
		ClipbrdViewer_set
		EnumClipbrdFmts
		EmptyClipbrd
		AddAtom
		FindAtom
		DeleteAtom
		AtomUsage
		AtomName
		AtomLength
		SystemAtomTable
		CreateAtomTable
		DestroyAtomTable
		_ClipbrdData_set
		ClipbrdText
		ClipbrdText_set
		_MessageBox
		MessageBox
		_MessageBox2
		MessageBox2
		LoadPointer
		SysPointer
		Alarm
		FlashWindow
	Do not use AUTOLOAD in OS2::DLL; moved to OS2::DLL::dll.
	New method OS2::DLL->module() (to replace botched ->new() method).
	New functions call20(), call20_p(), call20_rp3(), call20_rp3_p(),
		call20_Dos(), call20_Win(), call20_Win_0OK(),
		call20_Win_0OK_survive() in OS2::DLL to call C functions via
		pointers.

After @20218:
	select() workaround broke build of x2p.
	New OS2::Process (exported, undocumented) functions:
		kbdChar
		kbdhChar
		kbdStatus
		_kbdStatus_set
		kbdhStatus
		kbdhStatus_set
		vioConfig
		viohConfig
		vioMode
		viohMode
		viohMode_set
		_vioMode_set
		_vioState
		_vioState_set
		vioFont
		vioFont_set
	Make CheckOS2Error() macro return the error code.
	New dynaloaded entry point DosReplaceModule().
	New function OS2::replaceModule(target [, source [, backup]]).

After @21211:
	Make Cwd::sys_abspath() default to '.' and taint the result.
	Fix os2_process*.t to work if the default for VIO windows is maximized.
	Fix to avoid non-existing PIDs for get_sysinfo() broke pid==0.
	Restore default mode for pipes to be TEXT mode.

After @21379:
	New OS2::Process functions: __term_mirror_screen() __term_mirror()
		io_term().
	Fix a.out build: special-case thread::shared, pick up all the build
		static libraries, not only those for top-level modules.
	Fix DLLname() test to work with the static build too.
	New dynaloaded entry point RexxRegisterSubcomExe(); make OS2::REXX use
		it so it is not linked with REXX*.DLLs any more.
	If system "./foo", and empty "./foo" and "./foo.exe" exist,
		argv[0] would be set to junk.
	Make perl2cmd convert .pl files and keep the command-line switches.
	Make XSLoader and Perl-specific parts of DynaLoader to die with static
		builds (new variable $OS2::is_static used);
	Move perlmain.obj to the DLL; export main() as dll_perlmain(); create
		a library libperl_dllmain to translate the exported symbol
		back to main(); link the executables with this library instead
		of perlmain.obj.
	Add /li to link386's options (line number info in the .map file).
	Another break from fix to avoid non-existing PIDs for get_sysinfo().

After @21574:
	Update import libraries when perl version changes (e.g., due to rsync).
	New exported symbols dup() and dup2() [the wrappers have workaround
		for off-by-one error + double fault in the pre-Nov2003 kernels
		when a (wrong) filedescriptor which is limit+1 is dup()ed].
	Enable disabling fd via a FILE* (to avoid close() during fclose()).
	New dynaloaded entry point DosPerfSysCall().
	New function OS2::perfSysCall(cmd = CMD_KI_RDCNT, ulParm1= 0,
				      ulParm2= 0, ulParm3= 0); when called
		with cmd == CMD_KI_RDCNT = 0x63 and no other parameters,
		returns: in the scalar context: the tick count of processor 1;
			 in the list context: 4 tick counts per processor:
				total/idle/busy/interrupt-time.
		with cmd == CMD_KI_GETQTY == 0x41 and no other parameters,
		returns the CPU count.  Currently in other cases the return
		is void.
	New executables perl___<number> generated with decreased stack size
		(good when virtual memory is low; e.g. floppy boot).

After 5.8.2 (@21668):
	Fixes to installperl scripts to avoid junk output, allow overwrite
		of existing files (File::Copy::copy is mapped to DosCopy()
		with flags which would not overwrite).
	Disable DynaLoading of Perl modules with AOUT build (will core anyway).
	For AOUT build: Quick hack to construct directories necessary for
		/*/% stuff [maybe better do it from hints/os2.sh?].
	AOUT build: do -D__ST_MT_ERRNO__ to simplify linking with -Zmtd
		(e.g., to test GD: gd.dll linked with -Zmtd).
	MANIFEST.SKIP was read without a drive part of the filename.
	Rename Cwd::extLibpath*() to OS2::... (old names still preserved).
	Install perl.lib and perl.a too.
	New methods libPath_find(),has_f32(),handle(),fullname() for OS2::DLL.
	Enable quad support using long long.
	New C exported functions os2_execname(), async_mssleep(), msCounter(),
		InfoTable(), dir_subst(), Perl_OS2_handler_install(),
		fill_extLibpath().
	async_mssleep() uses some undocumented features which allow usage of
		highest possible resolution of sleep() while preserving low
		priority (raise of resolution may be not available before
		Warp3fp40; resolution is 8ms/CLOCK_SCALE).
		usleep() and select(undef,undef,undef,$t) are using this
		interface for time up to 0.5sec.
	New convenience macros os2win_croak_0OK(rc,msg), os2win_croak(rc,msg),
		os2cp_croak(rc,msg).
	Supports ~installprefix, ~exe, ~dll in PERLLIB_PREFIX etc (actual
		directories are substituted).
	New functions OS2::msCounter(), OS2::ms_sleep(), OS2::_InfoTable().
	Checks stack when fixing EMX being under-initialized (-Zomf -Zsys
		produces 32K stack???).
	New environment variables PERL_BEGINLIBPATH, PERL_PRE_BEGINLIBPATH,
		PERL_POST_BEGINLIBPATH, PERL_ENDLIBPATH, 
		PERL_PRE_ENDLIBPATH PERL_POST_ENDLIBPATH (~-enabled);
		PERL_EMXLOAD_SECS.
	Better handling of FIRST_MAKEFILE (propagate to subdirs during test,
		do not require Makefile.PL present).
	perl2cmd converter: do not rewrite if no change.
	README.os2 updated with info on building binary distributions and
		custom perl executables (but not much else).