* fhandler.h (fhandler_console::save_top): Save top of screen coordinates.
* fhandler_console.cc (dev::save_restore): Record top of screen coordinates.
Clear entire buffer when restoring saved buffer and try to position the cursor
on the save relative place on the screen.
written row and, because of this, don't bother trying to restore the screen
buffer size. Set cursor position after refilling buffer.
(fhandler_console::write): Use absolute paths when saving/restoring cursor
position or suffer odd problems after a saved screen is restored.
(fhandler_console::dwCursorPosition): Ditto.
(fhandler_console::wAttributes): Ditto.
(fhandler_console::b): New field encompassing previously disparate screen
buffer info.
(fhandler_console::save_bufsize): Rename from savebufsiz
(fhandler_console::save_buf): Rename sfrom savebuf.
(fhandler_console::save_cursor): New field.
(fhandler_console::save_restore): New function.
(fhandler_console::con): Rename from dev_state.
(fhandler_console::focus_aware): Accommodate name change.
* fhandler_console.cc: Use 'b' field of dev_console throughout instead of
disparate names. Accommodate dev_state -> con rename.
(dev_state:save_restore): New function. Attempt to save the entire screen
buffer rather than just the visible part. Clear the buffer when saving, like
Linux.
(fhandler_console::char_command): Use con.save_restore() for Save/restore
screen sequence.
* fhandler_console.cc (fhandler_console::scroll_buffer_screen): New function.
(fhandler_console::char_command): Use scroll_buffer_screen as appropriate.
(dev_console::scroll_buffer): Remove if 0'ed block.
(dev_console::scroll_window): Return bool indicating success.
(dev_console::scroll_screen): New function.
(dev_console::clear_screen): New function.
(fhandler_console::clear_screen): Make __reg3.
(fhandler_console::cursor_set): Ditto.
(fhandler_console::cursor_get): Ditto.
(fhandler_console::cursor_rel): Ditto.
* fhandler_console.cc (dev_console::scroll_buffer): Adapt from
fhandler_console.
(fhandler_console::scroll_buffer): Use dev_console function.
(dev_console::is_fullscreen): Delete.
(dev_console::scroll_window): Return true if we cleared the screen.
Shrink/grow buffer first before scrolling to ensure that there is sufficient
space after scrolling.
(fhandler_console::clear_screen): Make reg3, use dev_console function.
(dev_console::clear_screen): New function adapted from fhandler_console.
(fhandler_console::cursor_set): Make __reg3.
(fhandler_console::cursor_rel): Ditto.
(fhandler_console::cursor_get): Ditto.
(fhandler_console::write): Fix "reverse index".
* fhandler.h (dev_console::state): Remove trailing underscore.
(dev_console::args): Ditto.
(dev_console::nargs): Ditto.
(dev_console::info): Eliminate subclass.
(dev_console::dwEnd): New field.
(dev_console::scroll_window): New function.
(dev_console::is_fullscreen): Ditto.
(dev_console::fillin): Rename from fillin_info.
(fhandler_console::scroll_buffer): Rename from scroll_screen.
* fhandler_console.cc: Throughout s/dev_state\.info/dev_state/g. Accommodate
other name changes.
(dev_console::fillin): Accommodate rename. Notice max x/y written to. Forgo
memset if GetConsoleScreenBufferInfo fails.
(fhandler_console::scroll_buffer): Accommodate rename. Don't treat y
coordinate of zero as top of screen.
(dev_console::is_fullscreen): New function.
(dev_console::scroll_window): Ditto.
(fhandler_console::clear_screen): Just scroll the screen when clearing the
screen in a state where the screen buffer is bigger than the screen.
(fhandler_console::char_command): Try harder to get 'S' and 'T' working in the
presence of a screen buffer. Use temporary 'n' variable rather than
dev_state.args[0]. Use GNU ?: shortcut method.
* fhandler_console.cc (dev_console::console_attrs::set_cl_x): Honor buffer
locations.
(dev_console::console_attrs::set_cl_y): Ditto.
(fhandler_console::write): On reset, use absolute positioning to go to
beginning of buffer. Clear entire buffer.
(cltype): New enum.
(dev_console::console_attrs): Define struct name.
(dev_console::console_attrs::set_cl_x): New function.
(dev_console::console_attrs::set_cl_y): New function.
(fhandler_console::clear_screen): Redefine input params.
* fhandler_console.cc: Update copyright. Throughout, reflect change in
arguments to fhandler_console::clear_screeen.
(fhandler_console::mouse_aware): Simplify logic slightly.
(fhandler_console::scroll_screen): Remove hopefully obsolete win95 code.
(dev_console::console_attrs::set_cl_x): New function.
(dev_console::console_attrs::set_cl_y): New function.
(fhandler_console::clear_screen): Redefine input params. Calculate position
based on enum value.
(region_split): Change arguments. Simplify.
(ReadConsoleOutputWrapper): Remove coord argument since we now always use 0, 0.
Send extra arguments to region_split.
(delta): Ditto.
(ReadConsoleOutputWrapper): Ditto.
(fhandler_console::char_command): Use ReadConsoleOutputWrapper to avoid OOM
condition from ReadConsoleOutputW. Add more debugging.
included by default.
* winlean.h: Add long comment to explain why we have to define certain
symbols.
(_NORMALIZE_): Define.
(_WINNLS_): Drop definition and subsequent undef.
(_WINNETWK_): Ditto.
(_WINSVC_): Ditto.
2013-11-23 Eric Blake <eblake@redhat.com>
warnings between regparm definitions and declarations.
* smallprint.cc (__small_vswprintf): Conditionalize declaration and
setting of l_opt for only x86_64.
* spawn.cc (child_info_spawn::worker): Remove unused 'pid' variable.
* thread.cc (verifyable_object_isvalid): Temporarily define as
non-inline with gcc 4.7+, regardless of target.
* exceptions.cc (sig_handle_tty_stop): Make sure that incyg is cleared when
exiting if we have no parent process. Only wait for signal_arrived.
(sigpacket::process): Make continue_now a bool. Delay sending signal_arrived
until the end. Make code more defensive to avoid calling signal handler when
stopped. Only set signal_arrived when stopped.
* sigproc.cc (sig_hold): Rename from sigCONT. Make static.
(sig_send): Accommodate sigCONT -> sig_hold rename.
(wait_sig): Ditto.
* sigproc.h (sigCONT): Delete declaration.
* fhandler_console.cc (fhandler_console::write): Use new '%0c' facility to
print characters. Change to paranoid to avoid excessive strace output.
* fhandler_tty.cc (fhandler_pty_master::accept_input): Make frequent strace
printf "paranoid" to help cut down on strace output size.
* signal.cc (sigsuspend): Add standard syscall strace output.
(sigpause): Ditto.
(pause): Ditto.
* cygtls.h (_cygtls::reset_signal_arrived): New function.
* devices.in (exists_console): Use fhandler_console::exists () rather than raw
test.
* devices.cc: Regenerate.
* fhandler.h (fhandler_console::exists): Define new function.
* fhandler_console.cc (fhandler_console::need_invisible): Use
fhandler_console::exists () rather than raw test.
* spawn.cc: Rename assitant to assistant throughout.
(child_info_spawn::worker): Simplify test for when to start a non-Cygwin
process in its own process group. Just do it whenever we start a non-Cygwin
process.
(dtable::fixup_after_exec): Use fixup_close() and detect when it was not
possible to open an inherited file handle.
(dtable::fixup_after_fork): Defensively close any file handles which were not,
for some reason, inheritable.
* dtable.h: Make #pragma once.
(dtable::fixup_close): Declare new function.
* fhandler_console.cc (fhandler_console::set_unit): Set I/O handles to NULL
when this function fails.
specifically called setsid.
* fhandler_tty.cc (fhandler_pty_slave::dup): Ditto. Also add comment
documenting research into rxvt problem.
* fhandler_termios.cc (fhandler_termios::tcsetpgrp): Don't check specifically
for myself->ctty == -1. Test for > 0 as that is the correct test.
(fhandler_termios::sigflush): Ditto.
prevois patch.
(fhandler_console::open_setup): Install Ctrl-C handler here, if this
console is the controlling tty and the process hasn't been started by
a Cygwin process.
* cygheap.h (init_cygheap::manage_console_count): Ditto.
(init_cygheap::console_count): Ditto.
* fhandler.h (fhandler_console::has_a): Ditto.
(fhandler_console::free_console): Declare new function.
* fhandler_console.cc (fhandler_console::free_console): Define new function.
(fhandler_console::open_setup): Delete call to manage_console_count.
(fhandler_console::close): Ditto. Replace with call to free_console().
* fhandler_tty.cc (fhandler_pty_slave::open): Delete call to
manage_console_count.
(fhandler_pty_slave::cleanup): Ditto.
(fhandler_pty_slave::close): Call fhandler_console::free_console() if this is
our controlling tty.
* pinfo.cc (_pinfo::set_ctty): Skip function if tty in question == our ctty.
Delete call to manage_console_count.
* syscalls.cc (close_all_files): Avoid locking and avoid setting errno when
iterating over fds.
for stuff".
* fhandler.cc (fhandler_base_overlapped::wait_overlapped): Use simplified arg
form of cygwait.
* fhandler_console.cc (fhandler_console::read): Ditto.
* fhandler_audio.cc (fhandler_dev_dsp::Audio_out::waitforspac): Ditto.
(fhandler_dev_dsp::Audio_in::waitfordata): Ditto.
* fhandler_fifo.cc (fhandler_fifo::wait): Ditto.
* fhandler_serial.cc (fhandler_serial::raw_read): Ditto.
(fhandler_serial::raw_write): Ditto.
* select.cc (cygwin_select): Ditto.
* sigproc.h (cygwait): Rename from cygWFMO. Define two argument and single
argument forms of this function.
* fhandler_tty.cc (fhandler_pty_slave::open): Use method to query if tty is
open.
(fhandler_pty_slave::read): Send SIGHUP when master is detected as closed.
(fhandler_pty_common::close): Close input_available_event in callers since
master may need to signal it first.
(fhandler_pty_master::close): Lie and set input_available_event when closing,
then close input_available_event.
(fhandler_pty_slave::close): Close input_available_event explicitly here.
* tty.h (tty::is_master_closed): Declare new method.
never remember what it stands for.
(sig_handle_tty_stop): Remove obsolete call to sig_handle_tty_stop.
(_cygtls::call_signal_handler): Rework to grab signal information from
_main_tls if none is set for _my_tls. Try harder to keep thread locked.
(reset_signal_arrived): Delete.
* fhandler.cc (fhandler_base_overlapped::wait_overlapped): Use new cygWFMO call
to wait for an event + standard cygwin stuff. Modify debug output to
acccomodate new function.
* fhandler_console.cc (fhandler_console::read): Replace WaitForMultipleObjects
with cygWFMO.
* fhandler_socket.cc (get_inet_addr): Add comment.
* gendef (_sigdelayed): Remove call to reset_signal_arrived.
* sigproc.cc (_cygtls::signal_exit): Don't close my_readsig here unless we're
in the signal thread.
(create_signal_arrived): Create signal_arrived as auto-reset so that only one
thread is woken when a signal arrives.
* sigproc.h (cygWFMO): New function.
(reset_signal_arrived): Delete declaration.
Throughout, change syscalls to report on return values using new %R format
option.
* smallprint.cc (__small_vsprintf): Add parsing for %R to report on return
values and possible errno from syscalls.
* errno.cc (errmap): Add PRIVILEGE_NOT_HELD.
* fhandler_tty.cc (fhandler_pty_master::setup): When creating a thread use
shorter name to reduce debuggging output.
* select.cc (start_thread_pipe): Ditto.
(start_thread_serial): Ditto.
(start_thread_socket): Ditto.
(start_thread_mailslot): Ditto.
* sigproc.cc (talktome): Ditto.
Throughout rename _PROC_* to _CH_*.
* child_info.h: Include "pinfo.h".
(child_info_types): Rename _PROC_* -> _CH_* to avoid confusion with similarly
named constants.
(_PROC_*): Delete unneeded aliases.
(PROC_*): Ditto.
(CURR_CHILD_INFO_MAGIC): Ditto.
(cchildren): Define using "pinfo_minimal".
(child_info::set_saw_ctrl_c): Move to
(child_info_spawn::set_saw_ctrl_c): Here.
(child_info_spawn::lock): New field.
(child_info_spawn::hExeced): Ditto.
(child_info_spawn::ev): Ditto.
(child_info_spawn::~child_info_spawn): Move to sigproc.cc.
(child_info_spawn::child_info_spawn): Ditto.
(child_info_spawn::cleanup): Declare new function.
(child_info_spawn::set_saw_ctrl_c): Move to this class. Set flag only when
execed and return true when we have set the flag.
(child_info_spawn::child_info_spawn::signal_myself_exited): New function.
(child_info_spawn::wait_for_myself): Ditto.
(child_info_spawn::has_execed_cygwin): Ditto.
(child_info_spawn::has_execed): Ditto. Replaces "hExeced" test.
(child_info_spawn::operator HANDLE&): New operator.
(child_info_spawn::worker): Define old "spawn_guts" as class member.
(ch_spawn): Declare.
(have_execed): Define.
(have_execed_cygwin): Ditto.
* cygheap.h: Update comment.
* dcrt0.cc (get_cygwin_startup_info): Use _CH_* enums.
(child_info_spawn::handle_spawn): Ditto.
(dll_crt0_0): Ditto.
(multiple_cygwin_problem): Ditto.
* exceptions.cc (chExeced): Delete obsolete declaration.
(ctrl_c_handler): Reference set_saw_ctrl_c via new ch_spawn global.
* globals.cc (hExeced): Delete.
* pinfo.cc (pinfo::thisproc): Refer to cygheap as ::cygheap for consistency in
handle naming when -DDEBUGGING.
(pinfo::init): Accommodate case where myself.h is known but h0 is passed in.
(pinfo::pinfo): New constructor for setting up a pinfo passed in by previous
exec'or.
(pinfo::proc_waiter): Don't handle subprocess if we're in the process of
exiting due to an exec of a cygwin process. Don't close rd_proc_pipe here.
Close it when we actually are finished with the process. Use new
ch_spawn.signal_myself_exited function to let exec stub know that subprocess
has exited.
(pinfo::wait): Clarify debugging output.
(pinfo::release): Use "close_h" to close all handles to avoid races.
(winpids::add): Assume that elements of the array do not need to be zeroed and
are properly initialized or suffer problems on pinfo::release. Don't close
hProcess since release does that now.
* pinfo.h: Update comment.
(pinfo_minimal): Move some elements from pinfo here so that child_info_spawn
can use them.
(pinfo): Inherit from pinfo_minimal.
(pinfo::pinfo): Modify to accommodate new pinfo_minimal.
(pinfo::allow_remove): New function.
* sigproc.cc (proc_subproc): Use boolean values for true/false. Implement
PROC_EXEC_CLEANUP.
(proc_terminate): Set ppid = 1 since the procs list will only be iterated when
the process has not execed. Don't do any cleanup here since it is now handled
in pinfo::release.
(sigproc_init): Initialize sync_proc_subproc earlier.
(child_info::child_info): Assume that all important fields are properly
initialized and avoid memset().
(child_info_spawn::child_info_spawn): Specifically test for execing and then
set up appropriate fields in the struct.
(child_info_spawn::cleanup): Define new function.
(child_info_spawn::record_children): Specifically test for being execed here.
Fill in pinfo_minimal part of children array.
(child_info_spawn::reattach_children): Use constructor to duplicate information
for previous exec'or. Add more debugging output.
(remove_proc): Force deletion of thread when exiting due to exec. Rely on
pinfo::cleanup in release.
* sigproc.h (PROC_EXEC_CLEANUP): New enum.
(PROC_DETACHED_CHILD): Delete.
* spawn.cc (chExeced): Delete.
(child_info_spawn::worker): Rename from spawn_guts. Use elements of
child_info_spawn throughout rather than ch.whatever. Use ::cygheap to refer to
global rather than element of child_info. Use wait_for_myself() rather than
waitpid(). Call child_info_spawn::cleanup on function return.
(spawnve): Reflect movement of spawn_guts functionality into
child_info_spawn::worker.
* syscalls.cc (popen): Ditto.
* winsup.h (spawn_guts): Delete declaration.
(dtable::init_std_file_from_handle): Close console handle early, before
initialization. Build up openflags for passing to open_setup, just to be safe.
(last_tty_dev): New variable.
(fh_last_tty_dev): New macro.
(fh_alloc): Try again to keep track of previously opened tty, this time by just
saving the device and using that to potentially open an archetype. Avoid
setting the "/dev/tty" name if the creation of the fhandler failed.
(build_fh_pc): Remove unused second argument. Reorganize how and where the
name is set. Set last_tty_dev as appropriate. Avoid a NULL dereference in a
debug printf.
* dtable.h (build_fh_pc): Reflect removal of second parameter.
* fhandler.cc (fhandler_base::reset): Use new '<<' operator to copy pc since it
preserves any potentially previously set name.
(fhandler_base::set_name): Ditto.
* fhandler.h (fhandler_*::clone): Throughout use ccalloc to allocate new
fhandler, primarily to make sure that pc field is properly zeroed.
(fhandler_termios::last): Eliminate.
(fhandler_termios): Remove setting of last.
(fhandler_base::~fhandler_termios): Ditto.
* fhandler_console.cc (fhandler_console::open): Don't make decisions about
opening close-on-exec handles here since it makes no sense for archetypes.
(fhandler_console::init): Assume that input handle has already been opened.
* fhandler_termios.cc (fhandler_termios::last): Delete.
* path.h (path_conv::eq_worker): New function. Move bulk of operator = here.
(operator <<): New function.
(operator =): Use eq_worker to perform old functionality.
logs easier. Throughout, change /dev/tty* to /dev/pty*. Throughout, add flags
argument to fhandler_*::dup methods.
* devices.in: Rename (temporarily?) /dev/ttyN to /dev/ptyN. Add /dev/ptymN
devices for pty masters.
* devices.cc: Regenerate.
* devices.h (MAX_CONSOLES): Set to max number supported by devices.in.
(fh_devices::FH_PTMX): Rename from FH_PTYM.
(device::operator int): Return by reference.
* dtable.cc (fh_alloc): Take pc as an argument rather than just the device.
This makes debugging easier since more information is available. Actually
implement handling for already-allocated pty master devices. Make different
decisions when generating fhandler for not-opened devices. Add kludge to deal
with opening /dev/tty.
(cnew_no_ctor): New macro.
(build_fh_pc): Make debugging output more verbose. Use new clone() fhandler
interface to duplicate archetypes. Reset last term opened.
(dtable::dup_worker): Use Use new clone() fhandler interface to duplicate
archetypes. Pass flags to child dup handler.
(dtable::dup3): Set O_NOCTTY flag if newfd is not stdin/stdout/stderr.
* fhandler.cc (fhandler_base::reset): Rename from operator =() and reduce
functionality and sense of copy direction.
(fhandler_base::open_with_arch): Use published interface to query io_handle().
Use new copyto() fhandler method to copy from/to found archetype.
* fhandler.h: Throughout, delete size(), add copyout, clone, and fhandler_*
(void *) methods.
(fhandler_base::reset): Rename from operator =().
(fhandler_termios::is_dev_tty): Delete.
(fhandler_termios): change "protected" region to "private".
(fhandler_termios::is_dev_tty): Delete.
(fhandler_termios): Rearrange protected/public.
(fhandler_termios::fhandler_termios): Remember last fhandler_termios "opened".
(fhandler_termios::~fhandler_termios): Forget last fhandler_termios opened.
(ioctl): Rename from ioctl_termios. Take a void * argument. Reflect argument
change in pinfo::set_ctty.
(fhandler_console::dup): Declare new function. Set ctty here if appropriate.
(fhandler_pty_master::from_master): Privatize.
(fhandler_pty_master::to_master): Ditto.
(fhandler_pty_master::dwProcessId): Ditto.
(fhandler_pty_master::fhandler_pty_master): Add an `int' argument.
(fhandler_pty_master::open_setup): Declare new function.
(fhandler_pty_master::~fhandler_pty_master): Declare new method.
(fhandler_nodevice): Remove commented out function declaration.
* fhandler_console.cc: Use get_ttyp() instead of tc() throughout.
(fhandler_console::dup): Define new function to set controlling ctty on dup, as
appropriate.
(fhandler_console::ioctl): Reflect ioctl_termios name change.
(fhandler_console::setup): Rename from get_tty_stuff.
(fhandler_console::open_setup): Reflect argument change in pinfo::set_ctty.
(fhandler_console::fhandler_console): Set _tc here.
* fhandler_termios.cc (handler_termios::ioctl): Rename. Take a void * arg like
other ioctl functions.
* fhandler_tty.cc (fhandler_pty_slave::dup): Call myself->set_ctty to
potentially reset the controlling terminal.
(fhandler_pty_slave::ioctl): Reflect name/arg change for ioctl_termios.
(fhandler_pty_slave::fhandler_pty_slave): Take a "unit" argument. Call setup()
here so that we will know the unit number of this fhandler as soon as possible.
Set the unit as appropriate.
(handler_pty_master::open): Move most stuff to constructor and open_setup.
(handler_pty_slave::open_setup): Reflect argument change in pinfo::set_ctty.
(handler_pty_master::open_setup): Define new function.
(fhandler_pty_master::cleanup): Clear handles as a flag that the destructor
does not have to do "close" operations.
(fhandler_pty_master::close): Ditto.
(fhandler_pty_master::~fhandler_pty_master): Define new method.
(fhandler_pty_master::ioctl): Reflect name/arg change for ioctl_termios.
(fhandler_pty_master::setup): Allocate tty here. Rely on handles being
returned from allocated test rather than opening them here. Avoid setting
_need_nl here since it is already zeroed in the constructor. Set up device
information with DEV_TTYM_MAJOR.
* path.h (path_conv &operator =): Take a const argument.
(path_conv::dup): Ditto.
(pathconv_arg::PC_OPEN): New enum.
(pathconv_arg::PC_CTTY): Ditto.
(path_types::PATH_CTTY): Ditto.
(path_types::PATH_OPEN): Ditto.
(path_conv::isopen): New method.
(path_conv::isctty_capable): Ditto.
* path.cc (path_conv::check): Set PATH_OPEN and PATH_CTTY as appropriate.
* pipe.cc (fhandler_pipe::open): Use copyto to copy pipe handle.
* syscall.cc (open): Reinstate fd > 2 check to disallow resetting ctty on
non-std* handles.
* tty.cc (tty_list::allocate): Pass out handles for allocated tty. use
`not_allocated' to find unallocated ttys. Avoid keeping the lock since the
allocation of the tty should be sufficient to prevent multiple access.
(tty::not_allocated): Clarify comment. Rename. Return handles when an unused
tty is found. Simply test for existing tty.
(tty::exists): Rewrite to use `not_allocated'.
* tty.h (NTTYS): Reset down to actual number supported by devices.in.
(tty::not_allocated): Declare new function.
(tty_list::allocate): Pass out read/write tty handles. Zero them when not
found.
* fhandler_proc.cc: Reflect name change from FH_PTYM -> FH_PTMX.
* pinfo.h (pinfo::set_ctty): Reduce/reorder arguments passed in.
* pinfo.cc (pinfo::set_ctty): Ditto. Just use tc() built into the passed-in
fhandler_termios pointer. Return true if ctty is assigned.
* syscalls.cc (open): Call build_fh_pc with PC_OPEN flag. Set PC_CTTY if
appropriate.
(stat_worker): Remove is_dev_tty () stuff.
* dtable.cc (fh_alloc): Revert ill-advised setting of major/minor. Use new
is_dev_tty to remember that this device was opened as /dev/tty.
* fhandler.cc (fhandler_base::fstat): Remove leftover debugging statement.
(fhandler_base::tcgetsid): New function.
* fhandler.h ((fhandler_base::tcgetsid): Declare new function.
(fhandler_base::is_dev_tty): Ditto.
(fhandler_termios::opened_as_dev_tty): Declare new field.
(fhandler_termios::is_dev_tty): Declare new function.
(fhandler_termios::tcgetsid): Ditto.
(fhandler_pty_common::use_archetype): Move here from subclass.
(fhandler_pty_slave::use_archetype): Move up.
(fhandler_pty_master::use_archetype): Ditto.
* fhandler_console.cc (fhandler_console::ioctl): Rename second argument from
`buf' to `arg' for consistency. Call ioctl_termios for common fhandler_termios
ioctl handling.
* fhandler_tty.cc (fhandler_pty_slave::ioctl): Call ioctl_termios for common
fhandler_termios ioctl handling.
(fhandler_pty_master::ioctl): Ditto.
* fhandler_termios.cc (fhandler_termios::tcgetsid): Implement new function.
(fhandler_termios::ioctl_termios): Ditto. Implements TIOCSCTTY handling.
* syscalls.cc (stat_worker): Set /dev/tty device info when appropriate.
* termios.cc (tcgetpgrp): Avoid extraneous "isatty" check.
(tcgetsid): Implement new function.
* include/cygwin/version.h: Bump CYGWIN_VERSION_API_MINOR to 253.
* include/sys/termios.h (TIOCSCTTY): Define.
* environ.cc (conv_start_chars): Move to shared cygwin region and initialize at
compile time.
(match_first_char): New generic function for querying conv_start_chars.
(posify_maybe): Rename from posify.
(environ_init): Remove conv_envvars initialization. Don't check
conv_start_chars, just allow posify_maybe to make the decision.
* fhandler_console.cc (__vt100_conv): Fix formatting. Mark as const.