* path.cc (symlink_info::check_reparse_point): Return -1 for volume
mount points. Explain why.
(symlink_info::check): Call fs.update again for volume mount points.
Explain why.
(run_dtors): New wrapper function which avoids calling dtors more than once.
* dll_init.cc (dll_global_dtors): Use dll.run_dtors wrapper.
(dll_list::detach): Ditto.
(dll_list::alloc): Set has_dtors flag.
whether set_name should be called or not.
(dtable::dup_worker): Call build_fh_pc with new second parameter set
to false. Explain why. If fhandler's dup failed, delete rather than
cfree newfh and set newfh to NULL to indicate failure correctly.
* dtable.h (build_fh_pc): Change declaration according to above change.
Default set_name parameter to true.
* mmap.cc (mmap_record::free_fh): Delete rather than cfree fh.
ill-advised attempt to optimize "." and ".." handling by checking for
specific position in directory listing. Explain why.
(fhandler_disk_file.cc (fhandler_disk_file::readdir): Ditto.
Special-case opening file on NFS to fetch inode number and add longish
comment to explain why.
AF_LOCAL sockets.
(fhandler_socket::getpeername): Ditto.
* net.cc (socketpair): Don't set sun_path and peer_sun_path to
make sure getsockname and getpeername return the correct values
for AF_LOCAL sockets.
then constant size. Truncate returned data, but return full address
length as per POSIX.
(fhandler_socket::getsockname): Truncate returned data, but return full
address length as per POSIX.
(fhandler_socket::getpeername): Ditto.
(fhandler_socket::set_peer_sun_path): New method.
(fhandler_socket::get_peer_sun_path): New method.
* fhandler_socket.cc (fhandler_socket::fhandler_socket): Initialize
peer_sun_path to NULL.
(fhandler_socket::~fhandler_socket): Free peer_sun_path if necessary.
(fhandler_socket::dup): Duplicate peer_sun_path.
(fhandler_socket::accept): Ditto. Return fake unbound peer content
and len in case of AF_LOCAL sockets.
(fhandler_socket::getsockname): Always use local sockaddr_storage to
store socket address and copy over to incoming address. Handle every
namelen correctly per POSIX.
(fhandler_socket::getpeername): Ditto. Add code path to return
correct value for AF_LOCAL sockets.
(fhandler_socket::set_peer_sun_path): New method.
* net.cc (socketpair): Set peer_sun_path to empty string, just like
sun_path.
the native NT socket device.
(dtable::init_std_file_from_handle): Remove unused tmp_pathbuf
variable. Move check for sockets into FILE_TYPE_PIPE clause.
Rely on handle_to_fn having recognized socket, or check if
getsockopt works to accommodate NT4 shortcoming.
(handle_to_fn): Use tmp_pathbuf for OBJECT_NAME_INFORMATION
buffer and simplify code due to that. Check name returned by
NtQueryObject for socket device.
* debug.cc (lock_debug::acquired): Delete.
(lock_debug::lock_debug): Simplify.
(lock_debug::unlock): Ditto.
(find_handle): Don't set endh here.
(add_handle): Add new handle to beginning of the list rather than trying to
maintain an end list pointer.
(delete_handle): Minor optimization.
(mark_closed): Make logic clearer.
(verify_handle): Lock handle list before scanning.
(setclexec): Ditto.
(modify_handle): Ditto.
(newh): Don't lock handle list here. Assume caller did this.
(mark_closed): Ditto.
(close_handle): Remove unneeded #if.
* dtable.cc (dtable::dup2): Tweak debug output.
the length exceeds it.
* net.cc (fdsock): Use 65535 as window size, just like the comment says or we
run into problems with DuplicateHandle.
* path.cc (patch_conv::check): Use set_path to set invalid filename.
* path.h (path_conv::path_conv): Ditto.
(pdrive_buf): New place to hold information about cygdrive.
* fhandler_disk_file.cc (fhandler_cygdrive::set_drives): Store drive info in
pdrive_buf since get_win32_name() could now be too small to hold everything.
(fhandler_cygdrive::rewinddir): Reset pdrive to pdrive_buf.
(fhandler_cygdrive::closedir): Ditto.
* pipe.cc (fhandler_pipe::init): Be more defensive when referencing
get_win32_name(). Rework logic which made a copy of the POSIX path and then
never used it.
* cygheap.h: Remove stuff now included in cygheap_malloc.h and include that
file. Make cygheap_init a standard c++ function. Remove unneeded child_info
declaration.
* path.h: Include cygheap_malloc.h. Remove extra cstrdup declaration.
(path_conv): Reorganize to group variables together.
(path_conv::path): Make const char *.
(path_conv::known_suffix): Ditto.
(path_conv::normalized_path): Ditto.
(path_conv::path_conv): Reorganize initializers to reflect new element
ordering.
(path_conv::get_win32): Change return value to const char *.
(path_conv::set_path): Move back here from spawn.cc.
(parh_conv::modifiable_path): New function.
* path.cc (path_conv::add_ext_from_sym): Accommodate const'ness of
known_suffixes.
(path_conv::set_normalized_path): Ditto for normalized_path.
(path_conv::check): Use modifiable_path whereever we need to modify the path
element. Use set_path to set the path.
(path_conv::~path_conv): Accommodate new const'ness.
* spawn.cc (perhaps_suffix): Declare ext as const since that's what is being
returned.
(path_conv::set_path): Move back to path.h.
* winf.f (linebuf): Perform minor cleanup.
(linebuf::fromargv): Change second parameter to const.
* winf.cc (linebuf::fromargv): Ditto.
* dcrt0.cc (__main): Schedule dll_global_dtors to run
atexit before global dtors.
(do_exit): Delete test for ES_GLOBAL_DTORS and call to
dll_global_dtors.
Initialize to NULL in constructors. Drop normalized_path_size member.
(path_conv::size): Remove.
(path_conv::operator =): Always copy with sizeof path_conv. Always
duplicate path on cygheap.
(path_conv::set_path): Move implementation to spawn.cc.
* path.cc (path_conv::set_normalized_path): Always allocate
normalized_path on cygheap.
(path_conv::check): Don't work on path, rather allocate THIS_path in
TLS and use it throughout. When finished, allocate path on cygheap
and copy over. Defer tacking on extension after having copied path.
* spawn.cc (path_conv::set_path): Implement here.
(IMPLEMENT_FS_FLAG): New define.
(class fs_info): Convert filesystem type status flags into an enum
fs_info_type. Add cifs FS. Revert change to has_buggy_open and
has_buggy_fileid_dirinfo. Make them normal; status flags again.
Implement is_FS functions using IMPLEMENT_FS_FLAG.
* mount.cc (fs_info::update): Define MINIMAL_WIN_NTFS_FLAGS and
FS_IS_WINDOWS_NTFS. Add comment. Only test remote filesystems
for "NTFS" once. Add is_cifs check using FS_IS_WINDOWS_NTFS.
Set has_buggy_open flag for SUNWNFS. Set has_buggy_fileid_dirinfo
flag for UNIXFS and all cifs type filesystems. Only check for
caseinsensitivity once.
(fillout_mntent): Create locale fs_names array. Use for setting
_my_tls.locals.mnt_type.
* sigproc.cc (wait_for_sigthread): Ditto. Don't synchronize with wait_sig
after receiving an event that it is ready to go.
(init_sig_pipe): New function.
(wait_sig): Call init_sig_pipe to create pipes for communicating signals to
this process. Don't send sigCONT signal when initializing.
* fork.cc (frok::child): Accommodate wait_for_sigpipe parameter change.
* fhandler.h (fhandler_*::write): Make ssize_t/__stdcall.
(fhandler_*::write_overlapped): Ditto.
(fhandler_*::raw_write): Ditto.
(fhandler_*::readv): Ditto.
(fhandler_*::writev): Ditto.
(fhandler_*::raw_read): Make __stdcall.
* fhandler: Accommodate changes to read/write functions throughout.
* fhandler_clipboard.cc: Ditto.
* fhandler_console.cc: Ditto.
* fhandler_dsp.cc: Ditto.
* fhandler_fifo.cc: Ditto.
* fhandler_mailslot.cc: Ditto.
* fhandler_mem.cc: Ditto.
* fhandler_mem.cc: Ditto.
* fhandler_random.cc: Ditto.
* fhandler_tape.cc: Ditto.
* fhandler_tty.cc: Ditto.
* fhandler_virtual.cc: Ditto.
* fhandler_windows.cc: Ditto.
* fhandler_zero.cc: Ditto.
* syscalls.cc (readv): Use ssize_t as temp variable.
* fhandler.cc (fhandler_base::read): Coerce returned len to signed or it will
never be treated as < 0.
(fhandler_base::wait_overlapped): Minimize calls to GetLastError. Remove
duplicate debugging test. Fix error return.
* fhandler.h (fhandler_fifo::fifo_name): Declare new function.
(fhandler_fifo::close): Ditto.
(fhandler_fifo::dup): Ditto.
(fhandler_fifo::close_on_exec): Ditto.
* fhandler.cc (fhandler_fifo::fifo_name): Define new function.
(FIFO_BUF_SIZE): New define.
(cnp): Ditto.
(fhandler_fifo::open): Rework. Use cnp to open named pipe. Always open write
side as a client. Open dummy client when writing and can't connect.
(wait): Rework. Implement fifo_wait_for_next_client. Handle signals during
connect better. Add new fifo_wait_for_server code which polls
(sigh) waiting for server.
(fhandler_fifo::raw_read): Handle transition states when one client closes and
another is available.
(fhandler_fifo::close): Define.
(fhandler_fifo::dup): Ditto.
(fhandler_fifo::close_on_exec): Ditto.
(fs_info::clear): Clear fsn.
(fs_info::fsname): New read accessor for fsn.
* mount.cc (fs_info::update): Fill in fsn member with lowercased
filesystem name if filesystem is not well-known. Fall back to
"unknown" if filesystem name is missing.
(fillout_mntent): Print filesystem name retrieved in fs_info::update
rather than static string "unknown".
(fhandler_base::del_my_locks): Declare taking a del_lock_called_from
as argument.
* fhandler.cc (fhandler_base::close): Call del_my_locks with "on_close".
(fhandler_base::fixup_after_fork): Call del_my_locks with "after_fork".
(fhandler_base::fixup_after_exec): Call del_my_locks with "after_exec".
* flock.cc (fhandler_base::del_my_locks): Take del_lock_called_from
as argument. Call node->del_my_locks with NULL handle in after_exec
case. Explain why.
for MVFS. Explain why.
(fhandler_disk_file::utimens): Drop local variables lastaccess and
lastwrite. Copy timestamps right into FILE_BASIC_INFORMATION structure
to avoid copying them twice.
* wincap.cc: Implement above element throughout.
* wchar.h (__sjis_mbtowc): Declare.
(__eucjp_mbtowc): Ditto.
(__gbk_mbtowc): Ditto.
(__kr_mbtowc): Ditto.
(__big5_mbtowc): Ditto.
* syscalls.cc (internal_setlocale): Convert to char * function.
Return parameter by default. Return NULL if request to use a
charset can't be satisfied due to missing codepage support in the
underlying OS. Fix comment.
(setlocale): Store original locale. Restore to original locale if
internal_setlocale returns NULL.
* mount.h (fs_info::sttaus): Move filesystem type flags into
substructure. Add union to allow simple test for having set any
one filesystem type flag. Replace has_buggy_open flag with is_sunwnfs
flag. Replace has_buggy_fileid_dirinfo with is_unixfs flag.
(fs_info::got_fs): New private method.
(fs_info::has_buggy_open): New explicit implementation.
(fs_info::has_buggy_fileid_dirinfo): Ditto.
* mount.cc (fs_info::update): Optimize filesystem checks for speed.
* winsup.h (IMPLEMENT_STATUS_FLAG): Change write accessor to return
value just set.
* ntdll.h (PROCESSINFOCLASS): Remove unneeded trailing comma.
* pinfo.cc (_pinfo::dup_proc_pipe): Remove unneeded assignment.
* sigproc.cc (sig_send): Don't send signal to myself if this is an exec stub.
* Makefile.common (COMPILE_CXX): Add support for per-file overrides
to exclude $(nostdinc) and $(nostdincxx) from compiler flags.
(COMPILE_CC): Likewise for $(nostdinc).
winsup/cygwin/ChangeLog:
* Makefile.in (DLL_OFILES): Add libstdcxx_wrapper.o
(libstdcxx_wrapper_CFLAGS): Add flags for new module.
(_cygwin_crt0_common_STDINCFLAGS): Define per-file override.
(libstdcxx_wrapper_STDINCFLAGS, cxx_STDINCFLAGS): Likewise.
* cxx.cc: Include "cygwin-cxx.h".
(operator new): Tweak prototype for full standards compliance.
(operator new[]): Likewise.
(operator new (nothrow)): New fallback function.
(operator new[] (nothrow), operator delete (nothrow),
operator delete[] (nothrow)): Likewise.
(default_cygwin_cxx_malloc): New struct of pointers to the above,
for final last-resort fallback default.
* cygwin-cxx.h: New file.
(struct per_process_cxx_malloc): Define.
(default_cygwin_cxx_malloc): Declare extern.
* cygwin.din (__wrap__ZdaPv): Export new wrapper.
(__wrap__ZdaPvRKSt9nothrow_t, __wrap__ZdlPv,
__wrap__ZdlPvRKSt9nothrow_t, __wrap__Znaj,
__wrap__ZnajRKSt9nothrow_t, __wrap__Znwj,
__wrap__ZnwjRKSt9nothrow_t): Likewise.
* globals.cc (__cygwin_user_data): Init newly-repurposed 'forkee'
field (now 'cxx_malloc') to point to default_cygwin_cxx_malloc.
* libstdcxx_wrapper.cc: New file.
(__wrap__ZdaPv, __wrap__ZdaPvRKSt9nothrow_t, __wrap__ZdlPv,
__wrap__ZdlPvRKSt9nothrow_t, __wrap__Znaj,
__wrap__ZnajRKSt9nothrow_t, __wrap__Znwj,
__wrap__ZnwjRKSt9nothrow_t): Define wrapper functions for libstdc++
malloc operators and their overrides.
* winsup.h (default_cygwin_cxx_malloc): Declare extern.
* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
* include/sys/cygwin.h (struct per_process_cxx_malloc): Forward
declare here.
(struct per_process::forkee): Rename and repurpose from this ...
(struct per_process::cxx_malloc): ... to this.
* lib/_cygwin_crt0_common.cc: Include cygwin-cxx.h.
(WEAK): Define shorthand helper macro.
(__cygwin_cxx_malloc): Define and populate with weak references
to whatever libstdc++ malloc operators will be visible at final
link time for Cygwin apps and dlls.
(_cygwin_crt0_common): Always look up cygwin DLL's internal
per_process data, and don't test for (impossible) failure. Inherit
any members of __cygwin_cxx_malloc that we don't have overrides
for from the DLL's default and store the resulting overall set of
overrides back into the DLL's global per_process data.
memory used by socket select functions. Combine them into a single
struct select.
* cygtls.cc: Accommodate above change throughout.
(_cygtls::init_thread): Drop initalizing of sockevt to
INVALID_HANDLE_VALUE.
(_cygtls::fixup_after_fork): Reset sockevt to NULL.
(_cygtls::remove): Don't use sockevt value to bail out prematurely.
Set sockevt to NULL. Free malloced select members.
* select.h (struct select_socket_info): Drop max_w4 member.
* select.cc (thread_socket): Use INFINITE timeout value if number of
objects to wait for is <= MAXIMUM_WAIT_OBJECTS. Use num_w4 member
of select_socket_info struct rather than dropped max_w4.
(init_tls_select_info): New inline function to initialize TLS select
members.
(start_thread_socket): Just call init_tls_select_info to initialize TLS
select members and use them later on.
(socket_cleanup): Don't free select_socket_info pointer members since
they are thread local now.
* fhandler.h (fhandler_console::create_invisible_console): Declare new
function.
(create_invisible_console_workaround): Ditto.
* fhandler_console.cc (fhandler_console::create_invisible_console): Define new
function.
(create_invisible_console_workaround): Ditto. Add too much code to deal with
broken Windows 7. Use a helper app to start an invisible console window.
(fhandler_console::need_invisible): Reorganize to use helper functions to
create invisible console.
* spawn.cc (spawn_guts): Avoid zeroing already zeroed fields in si.
(initial_env): Set jit_debug when we are automatically starting a gdb process.
* dtable.cc (dtable::get_debugger_info): Don't tty tricks when we are being
debugged by our own captive gdb, as determined by jit_debug == true.
(dtable::init_std_file_from_handle): Detect errors when initializing a tty
early rather than at random points later.
* fhandler.h (fhandler_*::init): Return int to indicate success/failure.
* fhandler.cc (fhandler_base::init): Reflect change in return value.
* pipe.cc (fhandler_pipe::init): Ditto.
(fhandler_pipe::create_selectable): Don't say we're retrying when we aren't.
* fhandler_console.cc (fhandler_console::init): Ditto. Return success/failure.
* fhandler_serial.cc (fhandler_serial::init): Ditto.
* fhandler_tty.cc (fhandler_tty_slave::init): Ditto.
(fhandler_tty_slave::open): Make debugging output more detailed.
* tty.cc (tty_list::terminate): Don't close I/O handles before all slaves have
checked in.
(tty::slave_alive): Make a non-inlined function. Check if tty pipe handles can
be created as an additional exists check.
* tty.h (tty::slave_alive): Just define here.
to store and retrieve the SO_RCVBUF and SO_SNDBUF sizes.
* fhandler_socket.cc (fhandler_socket::dup): Duplicate new members.
(fhandler_socket::send_internal): Check for SO_SNDBUF size and
restrict send to 1 byte less per KB 823764. Leave loop immediately
if WSASendMsg has been used.
* net.cc (fdsock): Change comment again. Set buffer sizes to 65536.
Store values in fhandler_socket.
(cygwin_setsockopt): Store SO_RCVBUF and SO_SNDBUF sizes in
fhandler_socket.
(cygwin_sendto): Drop call to sig_dispatch_pending.
(cygwin_recvfrom): Ditto.
(cygwin_recvmsg): Ditto.
(cygwin_sendmsg): Ditto.
(select_record::select_record): Define do-nothing constructor for "new" to
avoid gratuitous zeroing.
(select_info): New base class.
(select_pipe_info): New class with methods for dealing with pipes.
(select_socket_info): New class with methods for dealing with sockets.
(select_serial_info): Dummy class for serial.
(select_mailslot_info): Dummy class for mailslots.
(select_stuff): Define device_specific_* as actual classes rather than void *.
* dtable.h (dtable::select_read): Accommodate return value change to 'bool' and
argument change to "select_stuff".
(dtable::select_write): Ditto.
(dtable::select_except): Ditto.
* dtable.cc (dtable::select_read): Accommodate return value change to 'bool'
and argument change to "select_stuff".
(dtable::select_write): Ditto.
(dtable::select_except): Ditto.
* fhandler.h: Excise select-related classes.
(fhandler_*::select_read): Change argument to select_stuff.
(fhandler_*::select_write): Ditto.
(fhandler_*::select_except): Ditto.
* select.cc (UNIX_FD_ZERO): Use memset rather than bzero.
(select_stuff::test_and_set): Change return type to bool. Allocate
select_record on entry and let fhandler_*::select_* operate on the start.next
field of select_stuff.
(pipeinf): Delete.
(select_pipe_info::select_pipe_info): New constructor. Allocates event for
controlling pipe waits.
(select_pipe_info::~select_pipe_info): New destructor. Destroy event. Stop
thread.
(select_pipe_info::add_watch_handle): New function.
(thread_pipe): Wait for the hEvent part of any overlapped pipes before peeking.
(start_thread_pipe): Don't allocate device_specific_pipe stuff here. Assume
that it has been allocated earlier.
(pipe_cleanup): Rely on select_pipe_info destructor to clean up pipe
paraphenalia.
(fhandler_*::select_*): Derive select_record from new select_stuff argument.
(fhandler_pipe::select_*): Ditto. Allocate pipe-specific field if not already
allocated.
(serialinf): Delete.
(thread_serial): serialinf -> select_serial_info.
(fhandler_base::ready_for_read): Rewrite to accommodate change in argument to
fhandler_*::select_*.
(socketinf): Delete.
(thread_socket): socketinf -> select_socket_info.
(mailslotinf): Delete.
(thread_mailslot): mailslotinf -> select_mailslot_info.
whether the overlapped event should be tested.
(fhandler_base::read_overlapped): Pass is_overlapped state to has_ongoing_io.
(fhandler_base::write_overlapped): Ditto.
* fhandler.h (fhandler_base::has_ongoing_io): Accommodate argument change.
* select.cc (peek_pipe): Ditto.
* fhandler.cc (fhandler_base::has_ongoing_io): Define new function.
(fhandler_base::read_overlapped): Use has_ongoing_io to avoid writing when
handle has not completed last I/O.
(fhandler_base::write_overlapped): Ditto.
* select.cc (peek_pipe): Be more careful about accessing hEvent field from
get_overlapped().
value.
(get_ipv4fromreg_ipcnt): New static function to fetch number of
configured IPv4 addresses for a given NIC from registry.
(get_ipv4fromreg): New static function to fetch configured IPv4
addresses for a given NIC from registry.
(get_friendlyname): New static function to generate friendly name.
(get_hwaddr): New static function to copy hardware address.
(get_xp_ifs): Restructure slightly. Add code to generate IPv4 entries
entries for interfaces which are disconnected.
* fhandler.cc (fhandler_base::fcntl): Fix comment.
(fhandler_base::wait_overlapped): Accept an optional len parameter. Use the
len parameter when WriteFile fails with ERROR_IO_PENDING. Make debug output
less alarming.
(fhandler_base::write_overlapped): Pass len to wait_overlapped.
* fhandler.h (fhandler_base::wait_overlapped): Add an optional argument
denoting the number of characters intended to be written.
* fhandler_tty.cc (fhandler_pty_master::close): Don't close archetype handles
when cygwin is still initializing since the handles aren't actually opened at
that point.
writes. Don't reset event handle when we see a ERROR_IO_PENDING.
* sigproc.cc (stopped_or_terminated): Use bool constants for consistency.
* wait.cc (wait4): Remove nonsensical comment.
* fhandler_proc.cc (format_proc_uptime): Use global system_info rather
than retrieving a local copy of the SYSTEM_INFO. Drop call to
GetSystemTimes and retrieve SystemPerformanceInformation on all systems
again with buffer size big enough for 64 bit systems.
(format_proc_stat): Use global system_info rather than retrieving a
local copy of the SYSTEM_INFO. Retrieve SystemPerformanceInformation
with buffer size big enough for 64 bit systems.
* fhandler_proc.cc (format_proc_uptime): Use GetSystemInfo to retrieve
processor count. Use GetSystemTimes when available to retrieve system
idle time. Improve debug output.
(format_proc_stat): Use GetSystemInfo to retrieve processor
count. Improve debug output. Ignore if SystemPerformanceInformation
returns error. Explain why.
(init_cygheap): Inherit locale field via mini_cygheap.
* cygheap.cc (cygheap_at_start): Define new variable.
(cygheap): Initialize as cygheap_at_start so that locale information is always
available.
(cygheap_init): Initialize cygheap iff it is set to cygheap_at_start.
* shared_info.h (memory_init): Accommodate argument change.
* memory.cc (memory_init): Accept an argument indicating whether cygheap should
be initialized or not.
* dcrt0.cc (child_info_fork::handle_fork): Pass false to memory_init().
(child_info_spawn::handle_spawn): Ditto.
(dll_crt0_0): Pass true to memory_init when not forking or execing.
* cygheap.h (cygheap_types::HEAP_2_DLL): New enum.
* dll_init.h (dll): Remove unused namelen field.
(dll_list::load_after_fork): Accommodate change in arguments.
* dll_init.cc (dll_list::alloc): Allocate dll information in the cygwin heap.
(dll_list::detach): Free dll information from the cygwin heap.
(dll_list::load_after_fork): Use dll information in the cygwin heap directly
rather than querying parent.
* fork.cc (frok::first_dll): Delete.
(frok::child): Don't report on first_dll. Don't pass it to load_on_fork.
(frok::parent): Don't set first_dll.
(fork): Ditto.
object. Explain why. Drop call to GetSystemInfo, rather call
getpagesize to get allocation granularity. Only align to allocation
granularity under WOW64. Use roundup2 to align.
(dll_list::detach): Call NtUnmapViewOfSection instead of VirtualFree.
* dll_init.cc: Fix formatting.
(dll_list::alloc): Only allocate as much memory for struct dll as
necessary for given DLL name.
(dll_list::load_after_fork): Only read a single page of parent memory.
Only read more if namelen indicates that it's necessary.
(set_clipboard): Add basic error checking. Set errno here. Per MSDN,
don't call GlobalFree on data block transferred to clipboard.
(fhandler_dev_clipboard::write): Drop setting errno after call to
set_clipboard.
(fhandler_dev_clipboard::read): Add basic error checking. Simplify code.
of the change to sys_cp_mbstowcs from 2009-05-30.
(sys_cp_mbstowcs): Slightly reformat. Fix comment to accommodate
change to sys_cp_wcstombs. Don't write to *ptr if dst is NULL.
Christopher Faylor
Corinna Vinschen
Eric Blake
Dave Korn