* exceptions.cc (unused_sig_wrapper): Remove _raise.
* sigproc.h (class sigframe): Default frames to skip to zero or suffer from
exuberant optimization.
* fhandler_tty.cc (fhandler_tty::write): Set appropriate errno when WriteFile
to pipe fails.
* pinfo.cc (pinfo::release): Move here from pinfo.h.
* sigproc.cc (proc_terminate): Remove bogus 'pinfo child' which caused strange
destruction of random regions of memory when destructor was invoked.
(_dll_crt0): To here.
(cygwin_dll_init): And here.
* external.cc (fillout_pinfo): Use more foolproof method for scanning for pids.
* pinfo.cc (set_myself): Eliminate myself_identity.init.
* sigproc.cc (wait_sig): Do it here instead to reduce the amount of time where
there could potentially be two processes with the same pid.
* spawn.cc (spawn_guts): Eliminate duplicate initialization.
* include/sys/cygwin.h: Mark unused PID_* elements.
exception handling on threads not created by cygwin.
* sigproc.cc (proc_terminate): Don't release pinfo structs since we are
exiting.
* include/sys/cygwin.h: Add CW_INIT_EXCEPTIONS.
(regopt): Use correct path to find LOCAL_MACHINE registry options.
* fhandler.cc (fhandler_base::open): Set binary mode only when binmode ==
O_BINARY.
* pipe.cc (pipe): Pipe handling should rely on binmode not _fmode now that the
two are different.
the process. Use new second argument to set_myself.
(cygwin_dll_init): Initialize exception list and constructor stuff here.
(_dll_crt0): And here. Also, deal with inherited pinfo shared memory region
from parent.
* pinfo.cc (set_myself): Accept a second argument signifying the a shared
memory region, passed from an execing parent.
(pinfo_init): Ditto.
* pinfo.h: Ditto.
* shared.h (child_info): Add a handle field to pass to child.
* spawn.cc (spawn_guts): Create a shared handle to pass to an execed child.
* winsup.h: Remove extraneous declaration.
required.
* errno.cc: Use DWORD to hold Windows errors.
(geterrno_from_win_error): New function.
(seterrno_from_win_error): Use geterrno_from_win_error to convert supplied
windows error (suggested by Corinna Vinschen).
* path.cc (symlink_info): Add error element.
* path.cc (path_conv::check): Remove errno setting. Use new symlink_info errno
element to set path_conv error, where appropriate.
(symlink_info::check): Set error element rather than attempting to manipulate
errno. Add more checks for trailing / and /.. even though they are currently
useless. Avoid setting EINVAL.
* path.cc (normalize_posix_path): Correct check for trailing /.
if fd is invalid. Return POLLERR for each valid fd if cygwin_select
returned with error.
include/sys/poll.h: Change POLLERR comment according to above change.
(cygwin_select): Move fd_set copying logic from ::wait to here. Use common
return through sell.poll.
(select_stuff::wait): Just return success or failure and let caller fill in
fd_set.
* pinfo.h (pinfo): Eliminate self-referential pointer to sidbuf since pinfo
structure exists at random locations now.
* fork.cc (fork): Use 'use_psid' element to control when the psid is relevant.
* shared.cc (sec_user): Ditto.
* spawn.cc (spawn_guts): Ditto.
* uinfo.cc (internal_getlogin): Ditto.
* syscall.cc (seteuid): Ditto. Set use_psid element.
since we are already bounds checked by default.
* thread.cc (ResourceLocks::Lock): Streamline this function since it is called
a lot.
(ReleaseResourceLock): Ditto.
recovery.
* spawn.cc (spawn_guts): Reorganize slightly to consolidate handling when there
is a CreateProcess error.
(_spawnve): Only longjmp back to vfork handling when a process has been
successfuly started.
* winsup.h (vfork_save): Extend to include frame info. Remove obsolete cpplus
conditionals.
* *.cc: put winsup.h before other headers (for __INSIDE_CYGWIN__);
use cur_environ() instead of just environ
* times.cc: remove import protections
* glob.c: add winsup.h
* localtime.c: ditto
* smallprint.c: ditto
* Makefile.in: don't __INSIDE_CYGWIN__ as it messes up profiling.
variable argument macros when possible.
* sigproc.cc: Throughout, use sigproc_printf rather than sip_printf.
* strace.cc (strace::prntf): Remove 'active' check, since callers are supposed
to ensure this.
(__system_printf): Remove. Subsumed by strace::prntf.
* winsup.h: Define "NEW_MACRO_VARARGS" to indicate when to use new macro
varargs capability.
(get_nonascii_key): Simplify previous patch to return ascii char if it is
non-zero. Add a second "temporary buffer" argument to help with thread safety.
* select.cc (peek_console): Pass a temporary buffer argument to
get_nonascii_key.
the changes below. Redefine process structure to avoid a fixed size table.
Redefine pinfo/_pinfo classes. Use these throughout.
* dcrt0.cc (dll_crt0_1): Accomodate set_myself argument change.
(__api_fatal): Accomodate _pinfo::record_death argument change.
* exceptions.cc (really_exit): Ditto.
(sig_handle_tty_stop): Use pinfo constructor to access process info.
(events_init): Don't create pinfo_mutex since it is no longer required.
* external.cc (fillout_pinfo): Use winpids class to iterate over all system
pids.
(cygwin_internal): lock_pinfo_for_update and unlock_pinfo are now noops.
* fhandler_termios.cc (fhandler_termios::set_ctty): Use pinfo constructor to
access process info.
* fork.cc (fork): Reorganize to initialize child info after the child has
started since that is when we know the child's winpid, which is necessary to
allocate the pinfo shared memory.
* mmap.cc (recreate_mmaps_after_fork): Change arg type to _pinfo.
* pinfo.cc: Rename pinfo methods to _pinfo throughout. Eliminate pinfo_list
stuff.
(set_myself): Accept a pid argument now. Call pinfo initializer to initialize
myself. Detect when this is an "execed" process and create an "indirect" pid
block.
(pinfo_init): Accomodate set_myself arg change.
(procinfo): Remove.
(pinfo::lock_pinfo): Remove.
(pinfo::unlock_pinfo): Remove.
(pinfo::init): New method. Allocates shared memory space for process pinfo
structure.
(pinfo::record_death): Don't call locking functions.
(cygwin_winpid_to_pid): Simplify by using new pinfo constructor.
(EnumProcessesW95): New function for iterating over processes on Windows 95.
(winpids::winpids): New constructor for winpids class. Sets up a list of
process ids.
(enum_init): Initialize w95/wnt pid enumerators.
* shared.cc (shared-info::initialize): Remove pid initialization.
* shared.h: Move pinfo stuff into pinfo.h.
(class shared_info): Remove pinfo_list element.
* signal.cc (kill_worker): Use pinfo constructor to access process info.
(kill_pgrp): Ditto. Use winpids methods to access list of processes.
* sigproc.cc: Throughout, modify to use _pinfo where appropriate.
(proc_exists (pid_t)): New function. Determines if a process exists based on
the pid.
(proc_exists (_pinfo *p): Use new proc_exists function above.
(proc_subproc): Copy pinfo stuff around rather than _pinfo pointers. Try to be
careful about releasing shared memory when we don't need it anymore. Remove
pinfo locks.
(remove_zombies): Remove pinfo memory when zombie is going away.
* sigproc.h: Reflect _pinfo/pinfo changes in sigproc.cc.
* spawn.cc (spawn_guts): Eliminate pinfo *child argument. Reorganize to only
initialize child pinfo after process has been started and we know the windows
pid.
(_spawnve): Reflect spawn_guts changes.
* syscalls.cc (setpgid): Use pinfo constructor to access process info.
(getpgid): Ditto.
(internal_getlogin): Use _pinfo.
* winsup.h: Eliminate pinfo_mutex. Eliminate spawn_guts declaration since it
is static now. Reflect set_myself argument change.
* include/sys/cygwin.h: Add some PID_* enums to accomodate new pinfo stuff.
* include/cygwin/version.h: Update minor version for cygdrive changes below.
* lib/cygwin_crt0.c: Inexplicably need to define alloca for newer compilers.
* fhandler.h (fhandler_console): Add new method.
* fhandler.cc (fhandler_console::set_cursor_maybe): New method.
(fhandler_console::read): Set cursor if it has moved to make it visible.
* external.cc (get_cygdrive_prefixes): New function.
(cygwin_internal): Add CW_GET_CYGDRIVE_PREFIXES case.
* path.cc (mount_info::read_cygdrive_info_from_registry): Read system cygdrive
prefix if user one is undefined.
(mount_info::write_cygdrive_info_to_registry): Write cygdrive prefix to the
appropriate registry hive. Overwrite in-memory copy of cygdrive, if
appropriate.
(mount_info::remove_cygdrive_info_from_registry): New method.
(mount_info::get_cygdrive_prefixes): New method.
(cygwin_umount): Remove cygdrive prefix, if appropriate.
* registry.cc (reg_key::killvalue): New method.
* shared.h (class reg_key): Add killvalue, remove_cygdrive_info_to_registry,
and get_cygdrive_prefixes declarations.
* include/sys/cygwin.h (cygwin_getinfo_types): Add CW_GET_CYGDRIVE_PREFIXES.
EXIT_SIGNAL bit and reorganizes exit value for backwards cygwin handling.
(handle_exceptions): Call signal_exit. Set "core dumped" bit.
(sig_handle): Call signal_exit. Set "core dumped" bit appropriately.
(_addenv): Remove check_null_empty_path from here.
(putenv): Call check_nullempty_path.
(setenv): Call check_nullempty_path for name as well here.
Don't report an error if value is empty string.
(environ_init): Revert usage of newp.
Change type to enum. Change storage class to static. Adjust comments.
(read_etc_passwd): Set passwd_state to different values when loaded
from file in contrast to being emulated.
(search_for): Return default passwd entry if passwd is emulated or
it's a request for the current user. Otherwise return NULL.
pseudo randomness.
* fhandler_random.cc: Rearrange. Use pseudo random number generator
as entropy source if system entropy isn't available and if device is
used as /dev/urandom. Allow initializing device by calling write().
to be set when variable blocksize mode is on.
* fhandler_raw.cc: Eliminate `\n' from trace output.
(clear): Set `varblkop' to 0.
(dup): Copy varblkop as well.
(writebuf): Care for variable blocksize.
(open): Ditto.
(raw_read): Ditto.
(raw_write): Ditto.
* fhandler_tape.cc (open): Ditto.
(ioctl): Ditto. Some cleanups.
* winsup.h: Add new macros sys_wcstombs and sys_mbstowcs.
* syscalls.cc (_link): Replace calls to mbstowcs by call to
sys_mbstowcs.
* uinfo.cc (internal_getlogin): Replace calls to wcstombs and
mbstowcs by calls to sys_wcstombs and sys_mbstowcs. Replace
usage of constants by meaningful defines. Use result of
GetSystemDirectory for HOMEPATH and HOMEDRIVE as a last resort.
* syscalls.cc (chroot): Set new root for process.
* path.cc (getcwd_inner): Add parameter to force use of
new root from chroot() call.
(ischrootpath): New macro.
(normalize_posix_path): Care for changed root dir.
(normalize_win32_path): Ditto.
(getcwd_inner): Ditto.
(chdir): Eliminate trailing path component consisting
entirely of dots.
* fork.cc (fork): Copy pinfo members regarding chroot().
* spawn.cc (_spawnve): Ditto.
* dir.cc (opendir): Don't use computed win32 path if
chroot() took place.
for second argument.
* path.h: Generalize SYMLINK_* constants to PC_*.
(path_conv): Create a new method. Fold third argument into second.
* dll_init.cc (dll_list::alloc): Try harder to find space to allocate dll
struct.
(dll_dllcrt0): Don't check sanity if we've already called dll_crt0.
* path.cc (path_conv::check): Don't check for a null or empty path unless
specifically told with a flag setting.
(check_null_empty_path): New function, adapted from macro.
* syscalls.cc (_rename): Use already-determined file attributes rather than
checking again.
* lib/cygwin/cygwin_attach.dll.c (cygwin_attach_dll): Use a static per_process
structure since this is apparently supposed to be zeroed.
* lib/cygwin_crt0.c (cygwin_crt0): Zero per_process structure sent to older
DLLs.
(environ_init): Explicitly initialize __cygwin_environ.
(cur_environ): New function. Detects when user has updated their environment.
* exec.cc: Use 'environ' define throughout rather than __cygwin_environ.
* spawn.cc: Ditto.
* winsup.h: Declare cur_environ, main_environ, environ.
detect when there are no fds to pass.
* dcrt0.cc (host_dependent_constants::init): Revert Sat Mar 18 01:32:04 2000
change.
(dll_crt0_1): Set "cygwin_finished_initializing" flag.
(dll_crt0): Don't perform memcpy if uptr is already set to internal structure.
(_dll_crt0): Remember location of programs envptr.
* dll_init.h (per_module, dll, dll_list): Revamp.
* dll_init.cc: Revamp. Use new classes.
* fork.cc (fork): Use new revamped dll, dll_list, and per_module stuff.
* environ.cc: Use __cygwin_environ throughout rather than the
user_data->envptr.
* exec.cc: Ditto.
* spawn.cc: Ditto.
* winsup.h: Declare update_envptrs, cygwin_finished_initializing.
* lib/_cygwin_crt0_common.cc (_cygwin_crt0_common): Revert previous change.
* lib/cygwin_attach_dll.cc (cygwin_attach_dll): Always pass in own per_process
structure or we end up overwriting information from the main program.
an fd.
* external.cc (cygwin_internal): Add handling of perfile_table setting.
* fhandler.cc (perfile_table): New global.
(fhandler_base::get_default_fmode): New method to return a file's default mode
based on its name.
(fhandler_base::open): Use get_default_mode method to determine a file's mode.
Record file mode in file flags.
* fhandler.h (fhandler_base): Declare get_default_fmode
* syscalls.cc (getmode): New function.
* sys/cygwin.h (__cygwin_perfile): New structure.
(cygwin_getinfo_types): Move outside of WINVER conditional.
(per_process): Move inside of WINVER conditional.
* include/sys/cygwin.h: Allow definition of per_process even when not compiling
with C++.
(cygwin_getinfo_types): Add CW_USER_DATA.
* lib/_cygwin_crt0_common.cc (_cygwin_crt0_common): Get __cygwin_user_data
pointer from cygwin_internal. If it doesn't exist, return failure. Use either
this pointer or passed in pointer throughout. Clear forkee.
* lib/crt0.h: Accomodate argument changes to _cygwin_crt0_common.
* lib/cygwin_attach_dll.c (cygwin_attach_dll): Reorganize to allow use of newer
binaries with older DLLs. Detect older DLLs when _cygwin_crt0_common returns 0
and allocate space for a per_process structure on the stack.
* lib/cygwin_crt0.c (cygwin_crt0): Ditto.
(dll_crt0_1): Eliminate user_data initialization.
(dll_crt0): Set up impure_ptr_ptr for older executables.
(cygwin_dll_init): Eliminate user_data initializations.
(__api_fatal): Don't check for user_data initialization.
* dll_init.cc (struct dll): Store entire contents of per_process rather than
just a pointer.
(add): Ditto.
(initOneDll): Don't check for user_data initialization.
(DllList::recordDll): Store contents of per_process argument.
(DllList::detachDll): Pass address of per_process field.
(DllList::initAll): Ditto.
(DllList::doGlobalDestructorsOfDlls): Ditto.
(DllListIterator::operator *): Ditto.
(dll_dllcrt0): Default to __cygwin_user_data if arg is NULL.
* include/sys/cygwin.h: Reorganize per_process to eliminate obsolete fields and
accomodate new way of initializing.
* lib/_cygwin_crt0_common: Initialize _impure_ptr from
__cygwin_user_data.impure_ptr.
* (dummy_autoload): Add functions used in fhandler_console.
* fhandler_console.cc (fhandler_console::read): Use ENCHANCED_KEY flag to
distinguish extended keys. Translate an input character from the OEM code page
to the ANSI code page.
* (fhandler_console::write_normal): Translate output characters from the ANSI
code page to the OEM code page.
* syscalls.cc (_link): Use MultiByteToWideChar instead of OemToCharW.
(handle_exceptions): Be more assertive in finding ebp for use under W2K.
Create a dummy stack frame for cases where program is dying and a stack dump is
being output.
(sig_handle): Fill out a GetThreadContext for use with a user-generated "core
dump".
* fork.cc (fork): Use above defines instead of numerical constants.
* shared.cc (sec_user): Ditto.
* shared.h (class pinfo): Ditto.
* syscall.cc (seteuid): Ditto.
* spawn.cc (_spawnve): Ditto. Eliminate conditional.
(spawn_guts): Set child->uid = USHRT_MAX when user context will be
changed in child process.
* uinfo.cc (uinfo_init): Check for myself->uid instead of myself->psid
to avoid reloading of /etc/passwd on process startup if ntsec is off.
Use above defines instead of numerical constants.
* security.cc: Move define for MAX_SID_LEN to winsup.h.
appropriate.
(LIBCOS): Find additional stub library stuff in their own subdirectory.
* dcrt0.cc: Convert user_data pointer to static __cygwin_user_data area.
(do_global_ctors): Check magic_bisquit for initialization.
(dll_crt0_1): First group of premain functions prior to fd initialization. Run
second group before calling main.
(dll_crt0 ()): New function, called from new initialization code.
(dll_crt0 (per_process *uptr)): Call new dll_crt0 () function on
initialization.
* debug.cc (thread_stub): Initialize bottom of stack with per-thread info.
* environ.cc (parse_thing): Use binmode global to control CYGWIN=binmode
behavior.
* fhandler.cc (fhandler_base::open): Allow explicit setting of __fmode to
O_BINARY or O_TEXT to override disk mount settings.
* libcmain.cc: Move to lib subdirectory.
* libccrt0.cc: Ditto.
* dll_main.cc: Ditto.
* dll_entry.cc: Ditto.
* getopt.c: Ditto.
* thread.cc (thread_init_wrapper): Call ExitThread explicitly rather than
returning, as a preliminary step towards placing per thread info at the bottom
of the stack.
* winsup.h: Move per_process class to include/sys/cygwin.h. Declare new
dll_crt0().
* include/cygwin/version.h: Bump API minor version.
* binmode.c: New file.
* textmode.c: Ditto.
* lib/_cygwin_crt0_common.cc: Ditto.
* lib/crt0.h: Ditto.
* lib/cygwin_attach_dll.c: Ditto.
* lib/cygwin_crt0.c: Ditto.
* lib/dll_entry.cc: Ditto.
* lib/dll_main.cc: Ditto.
* lib/getopt.c: Ditto.
* lib/libcmain.c: Ditto.
* lib/premain0.c: Ditto.
* lib/premain1.c: Ditto.
* lib/premain2.c: Ditto.
* lib/premain3.c: Ditto.
internal_getlogin().
* uinfo.cc (internal_getlogin): Use impersonation token instead
of process token in case of active impersonation. Add some comments.
(uinfo_init): Initializing myself->token and myself->impersonated
before calling internal_getlogin(). Add some comments.
* spawn.cc (_spawnve): Ditto.
* passwd.cc: Remove static from `passwd_in_memory_p'.
(read_etc_passwd): Remove static.
* uinfo.cc: Move global declaration of `read_etc_group' and
`group_in_memory_p' into `uinfo_init'.
(internal_getlogin): Try to get SID from current process first.
(uinfo_init): Don't set uid and gid if `myself' has a valid SID.
Only load /etc/passwd and /etc/group in that case.
for existing user hive.
Use MAX_PATH instead of numerical constant for array size.
Use return code of RegLoadKeyA instead of GetLastError for error output.
and `RegLoadKeyA'.
* registry.cc (get_registry_hive_path): New function.
(load_registry_hive): Ditto.
* security.cc (convert_sid_to_string_sid): New function.
(get_ssid): Renamed to `convert_string_sid_to_sid'.
(get_pw_sid): Call `convert_string_sid_to_sid' instead of `get_ssid'.
(get_gr_sid): Ditto.
(get_admin_sid): Ditto.
(get_system_sid): Ditto.
(get_creator_owner_sid): Ditto.
(get_world_sid): Ditto.
* shared.h: New prototypes for `get_registry_hive_path' and
`load_registry_hive'.
* spawn.cc (spawn_guts): Set child->psid to NULL to force calling
`internal_getlogin' from child process in case of changing user context.
Call `load_registry_hive' in case of changing user context.
(_spawnve): Copy user infos only if user context remains the same.
* uinfo.cc: Add load statement for `NetUserGetInfo'.
Remove load statement for `NetGetDCName'.
(internal_getlogin): Rewrite to speed up process startup
and to correct user environment in case user context changes.
(uinfo_init): Call internal_getlogin only if myself->psid is NULL,
that is user context changes.
* winsup.h: Add prototypes for `convert_sid_to_string_sid',
`convert_string_sid_to_sid' and `get_pw_sid'.
`cygwin_set_impersonation_token'.
* dcrt0.cc (dll_crt0_1): Eliminate superfluous conditional
statements.
Add load statements for `ImpersonateLoggedOnUser', `LogonUserA'
and `RevertToSelf'.
* fork.cc (fork): Care for correct impersonation of parent
and child process.
* security.cc (cygwin_set_impersonation_token): New function.
(cygwin_logon_user): Ditto.
shared.h (class pinfo): New members `orig_uid', `orig_gid',
`real_uid' nad `real_gid'.
spawn.cc (spawn_guts): Care for impersonation when starting
child process in a different user context.
* syscalls.cc (setgid): Call `setegid' now. Set real_gid.
(setuid): Call `seteuid' now. Set real_uid.
(seteuid): Functionality moved from setuid to here. Care for
correct impersonation.
(setegid): Functionality moved from setgid to here.
* uinfo.cc (uinfo_init): Initialization of additional pinfo
members.
(getuid): Return real uid.
(getgid): Return real gid.
(geteuid): Return effective uid.
(getegid): Return effective gid.
include/sys/cygwin.h: Add prototypes for `cygwin_logon_user' and
`cygwin_set_impersonation_token'.
include/cygwin/version.h: Bumb API minor version to 22.
* path.cc: Ditto.
(normalize_posix_path): Add some extra debugging info.
(chdir): Ditto. Store chdir'ed posix and MS-DOS directory names in "cache"
here rather than trying to derive them later.
(mount_slash): Eliminated.
(mount_info::read_mounts): Eliminate looking up existing entries. The
loop for deleting cygpath entries is done only when such entries exist.
(mount_info::from_registry): Eliminate sorting.
(mount_info::add_item): Call add_reg_mount if necessary. Check nmounts
more precisely. Use strcasematch in looking up existing entries.
(mount_info::del_item): Call del_reg_mount if necessary. Use
strcasematch. Use memmove instead of memcpy.
(mount_info::import_v1_registry): Everything is done in this method.
(mount_info::to_registry): Eliminated.
(mount_info::from_v1_registry): Eliminated.
(cygwin_umount): Simply call del_item.
shared.h: Modify the declaration of add_item and del_item. Remove the
declaration of from_v1_registry.
* autoload.h: Add additional field to autoload block for handling unimplemented
functions.
(LoadDLLfuncEx): New function which accepts additional parameter for
controlling unimplemented function behavior.
(LoadDLLfunc): Use LoadDLLfuncEx.
* dcrt0.cc: Use new arguments for LoadDLLfunc. Add advapi32 routines.
(noload): Rewrite in assembler. Handle new unimplemented function type.
* exceptions.cc: Eliminate another vestige of StackWalk stuff.
* net.cc: Use new arguments for LoadDLLfunc.
* uinfo.cc: Ditto.
* config.h.in: Remove obsolete define.
* path.h (isdrive): New macro.
* dcrt0.cc (globify): Use new macro to determine if a string refers to an
MS-DOS drive.
* environ.cc (winenv): Ditto.
* spawn.cc (find_exec): Ditto.
* path.cc (get_raw_device_number): Ditto.
(mount_info::conv_to_posix_path): Ditto.
(chdir): Ditto.
(cygwin_posix_path_list_p): Ditto.
(cygwin_split_path): Ditto.
(path_conv::check): Move tmp_buf to beginning of function since it can be used
earlier in the loop. Use tmp_buf rather than 'root' to hold root information.
(mount_info::conv_to_win32_path): Add trailing slash to end of mount path when
it translates to a drive. Add defensive code to avoid writing beyond the end
of 'dst'.
return always 1 for now.
(mkdir): Call set_file_attribute explicitely with S_IFDIR mode bit.
* syscalls.cc (chown_worker): Ditto.
(chmod): Ditto.
* security.cc (get_nt_attribute): Fix error in debug output.
Never set FILE_DELETE_CHILD for files.
Construct appropriate inherit attribute according to file type.
directory name when the ms-dos path spec is a root directory of a device.
* registry.cc (reg_key::build_reg): Set 'key_is_invalid' flag rather than using
an INVALID_HANDLE_KEY.
(reg_key::get_int): Test for key validity before performing registry
operations.
(reg_key::set_int): Ditto.
(reg_key::get_string): Ditto.
(reg_key::set_string): Ditto.
(reg_key::kill): Ditto.
(reg_key::~reg_key): Ditto.
Christopher Faylor
DJ Delorie
Corinna Vinschen