* data.c (pure_write_error):
Use xsignal2, not Fsignal, as Fsignal might return.
* eval.c (set_backtrace_debug_on_exit): Now static.
(backtrace_p, backtrace_top, backtrace_next, record_in_backtrace):
No longer inline. EXTERN_INLINE is needed only for functions
defined in .h files. Reindent function header as per GNU style.
(backtrace_p, backtrace_top, backtrace_next):
Mark EXTERNALLY_VISIBLE so they don't get optimized away by the
compiler or linker. Add extern decls to pacify gcc -Wall.
* frame.c, frame.h (Qgeometry, Qworkarea, Qmm_size, Qframes, Qsource):
Now static.
* frame.c (free_monitors): Define only on platforms that need it.
* nsterm.m (ns_term_init):
* process.c (catch_child_signal):
Don't worry about whether SIGCHLD is defined, as SIGCHLD is
defined on all porting targets these days.
* process.c, process.h (catch_child_signal):
Make it extern only if NS_IMPL_GNUSTEP is defined.
* nextstep/templates/Info-gnustep.plist.in: Add NSDocumentClass EmacsDocument.
* src/nsfns.m (x_set_foreground_color, x_set_background_color): Use
EmacsCGFloat.
(ns_implicitly_set_icon_type, Fx_create_frame): Make static, remove
unused variables.
(Fns_read_file_name): Keep track if panel is for save. Use
ns_filename_from_panel/ns_directory_from_panel.
(Fns_list_services): delegate only used for COCOA.
(Fns_convert_utf8_nfd_to_nfc): Remove warning for GNUStep. Just
return the input if GNUStep.
(x_screen_planes): Remove.
(Fxw_color_values): Use EmacsCGFloat
(Fns_display_monitor_attributes_list): Only get screen number for
Cocoa.
(getDirectory, getFilename): Removed from EmacsOpenPanel and
EmacsSavePanel.
(EmacsOpenPanel🆗): Use ns_filename_from_panel and
ns_directory_from_panel.
* src/nsfont.m (ns_attribute_fvalue, ns_spec_to_descriptor)
(ns_charset_covers, ns_get_covering_families, nsfont_open):
Use F suffix on floats.
(ns_char_width): Returns CGFloat.
(ns_ascii_average_width): w is CGFloat instead of float.
(nsfont_draw): cbuf and c are unsigned. Cast to char* in call to
DPSxshow.
(ns_glyph_metrics): CGFloat instead of float.
* src/nsimage.m (setXBMColor:, getPixelAtX:Y:): Use EmacsCGFloat.
* src/nsmenu.m (ns_update_menubar): Make static.
(x_activate_menubar): Surround with ifdef NS_IMPL_COCOA
(fillWithWidgetValue:): Add cast to SEL for setAction.
(addSubmenuWithTitle:forFrame:): Add cast to SEL for action.
(update_frame_tool_bar): Update code for GNUStep.
(clearAll): New method.
(addDisplayItemWithImage:idx:tag:helpText:enabled:): Handle new tag
argument. Call insertItemWithItemIdentifier when NS_IMPL_GNUSTEP. Move
identifierToItem setObject and activeIdentifiers addObject before
call to insertItemWithItemIdentifier.
(validateVisibleItems): Fix indentation.
(toolbarAllowedItemIdentifiers:): Return activeIdentifiers.
(initWithContentRect:styleMask:backing:defer:): Add ClosableWindow and
UtilityWindow to aStyle, remove call to setStyleMask.
* src/nsselect.m (ns_get_local_selection): Remove unused variable type.
* src/nsterm.h (EmacsCGFloat): Typedef for OSX and GNUStep when the size
of CGFloat differs.
(EmacsApp): New variable nextappdefined. Declare sendFromMainThread
when NS_IMPL_GNUSTEP.
(EmacsDocument): Declare when NS_IMPL_GNUSTEP.
(EmacsView): Remove unlockFocusNeedsFlush, add windowDidMove.
(EmacsToolbar): Add clearAll. Add tag argument to
addDisplayItemWithImage.
(EmacsSavePanel, EmacsOpenPanel): Remove getFilename and getDirectory.
* src/nsterm.m: Include src/process.h if NS_IMPL_GNUSTEP.
(ns_menu_bar_is_hidden, menu_will_open_state): Define only if
NS_IMPL_COCOA.
(x_set_cursor_type): Remove declaration.
(ns_update_begin): Only use r and bp if NS_IMPL_COCOA.
(ns_update_end, ns_focus, ns_unfocus): Remove GNUStep specific code.
(x_set_window_size): Remove 3 pixels from toolbar if NS_IMPL_GNUSTEP.
(ns_get_color): Use F suffix on float.
(ns_color_to_lisp, ns_query_color): Use EmacsCGFloat.
(ns_get_rgb_color): Remove.
(x_set_frame_alpha): Move view inside NS_IMPL_COCOA.
(note_mouse_movement): x and y are CGFloat.
(ns_draw_fringe_bitmap): Remove unused rowY.
Change #if to COCOA && >= 10_6.
(ns_draw_window_cursor): Remove unused overspill.
(ns_draw_underwave): width and x are EamcsCGFloat.
(ns_draw_box): thickness is CGFloat.
(ns_dumpglyphs_image): Change #if to COCOA && >= 10_6.
(ns_send_appdefined): When NS_IMPL_GNUSTEP, redirect to main thread
if not in main thread.
(ns_get_pending_menu_title, ns_check_menu_open)
(ns_check_pending_open_menu): Put inside #if COCOA && >= 10_5.
(ns_term_init): Call catch_child_signal if NS_IMPL_GNUSTEP && SIGCHLD.
(sendFromMainThread:): New method.
(changeFont:): size is CGFloat.
(keyDown:): Check for Delete when NS_IMPL_GNUSTEP.
Disable warning about permanent text.
(characterIndexForPoint:): Adjust return type depending on GNUStep
version.
(mouseDown:): delta is CGFloat.
(updateFrameSize): Remove unised variable f.
(initFrameFromEmacs): Move toggleButton inside NS_IMPL_COCOA.
Cast float to EmacsCGFloat.
(windowWillUseStandardFrame:defaultFrame:): Set maximized_height
also to -1 when restoring.
(windowDidExitFullScreen:): Put call to updateCollectionBehaviour
inside NS_IMPL_COCOA.
(toggleFullScreen:): Put call to toggleFullScreen inside
NS_IMPL_COCOA. Cast float to EmacsCGFloat.
(setPosition:portion:whole:): por is CGFloat.
(getMouseMotionPart🪟x:y:): Add F suffix to float.
(mouseDown:): Use CGFloat.
(mouseDragged:): Remove unised variable edge.
(EmacsDocument): Implement for NS_IMPL_GNUSTEP.
* src/process.c (catch_child_signal): New function.
(init_process_emacs): Call it.
* src/process.h (catch_child_signal): Declare.
* callproc.c, process.h (record_kill_process):
New function, containing part of the old call_process_kill.
(call_process_kill): Use it.
This does not change call_process_kill's behavior.
* process.c (Fdelete_process): Use record_kill_process to fix a
race condition that could cause Emacs to lose track of a child.
Fixing this bug required some cleanup of the signal-handling code.
As a side effect, this change also fixes a longstanding rare race
condition whereby Emacs could mistakenly kill unrelated processes,
and it fixes a bug where a second C-g does not kill a recalcitrant
synchronous process in GNU/Linux and similar platforms.
The patch should also fix the last vestiges of Bug#9488,
a bug which has mostly been fixed on the trunk by other changes.
* callproc.c, process.h (synch_process_alive, synch_process_death)
(synch_process_termsig, sync_process_retcode):
Remove. All uses removed, to simplify analysis and so that
less consing is done inside critical sections.
* callproc.c (call_process_exited): Remove. All uses replaced
with !synch_process_pid.
* callproc.c (synch_process_pid, synch_process_fd): New static vars.
These take the role of what used to be in unwind-protect arg.
All uses changed.
(block_child_signal, unblock_child_signal):
New functions, to avoid races that could kill innocent-victim processes.
(call_process_kill, call_process_cleanup, Fcall_process): Use them.
(call_process_kill): Record killed processes as deleted, so that
zombies do not clutter up the system. Do this inside a critical
section, to avoid a race that would allow the clutter.
(call_process_cleanup): Fix code so that the second C-g works again
on common platforms such as GNU/Linux.
(Fcall_process): Create the child process in a critical section,
to fix a race condition. If creating an asynchronous process,
record it as deleted so that zombies do not clutter up the system.
Do unwind-protect for WINDOWSNT too, as that's simpler in the
light of these changes. Omit unnecessary call to emacs_close
before failure, as the unwind-protect code does that.
* callproc.c (call_process_cleanup):
* w32proc.c (waitpid): Simplify now that synch_process_alive is gone.
* process.c (record_deleted_pid): New function, containing
code refactored out of Fdelete_process.
(Fdelete_process): Use it.
(process_status_retrieved): Remove. All callers changed to use
child_status_change.
(record_child_status_change): Remove, folding its contents into ...
(handle_child_signal): ... this signal handler. Now, this
function is purely a handler for SIGCHLD, and is not called after
a synchronous waitpid returns; the synchronous code is moved to
wait_for_termination. There is no need to worry about reaping
more than one child now.
* sysdep.c (get_child_status, child_status_changed): New functions.
(wait_for_termination): Now takes int * status and bool
interruptible arguments, too. Do not record child status change;
that's now the caller's responsibility. All callers changed.
Reimplement in terms of get_child_status.
(wait_for_termination_1, interruptible_wait_for_termination):
Remove. All callers changed to use wait_for_termination.
* syswait.h: Include <stdbool.h>, for bool.
(record_child_status_change, interruptible_wait_for_termination):
Remove decls.
(record_deleted_pid, child_status_changed): New decls.
(wait_for_termination): Adjust to API changes noted above.
Fixes: debbugs:12980
This is a backport from the trunk, consisting of:
2012-11-17 Eli Zaretskii <eliz@gnu.org>
* nt/inc/sys/wait.h: New file, with prototype of waitpid and
definitions of macros it needs.
* nt/inc/ms-w32.h (wait): Don't define, 'wait' is not used anymore.
(sys_wait): Remove prototype.
* nt/config.nt (HAVE_SYS_WAIT_H): Define to 1.
* src/w32proc.c (create_child): Don't clip the PID of the child
process to fit into an Emacs integer, as this is no longer a
restriction.
(waitpid): Rename from sys_wait. Emulate a Posix 'waitpid' by
reaping only the process specified by PID argument, if that is
positive. Use PID instead of dead_child to know which process to
reap. Wait for the child to die only if WNOHANG is not in
OPTIONS.
(sys_select): Don't set dead_child.
* src/sysdep.c (wait_for_termination_1): Remove the WINDOWSNT portion,
as it is no longer needed.
* src/process.c (waitpid, WUNTRACED) [!WNOHANG]: Remove definitions,
no longer needed.
(record_child_status_change): Remove the setting of
record_at_most_one_child for the !WNOHANG case.
2012-11-03 Paul Eggert <eggert@cs.ucla.edu>
Fix a race condition that causes Emacs to mess up glib (Bug#8855).
This is a backport from the trunk.
The symptom is a diagnostic "GLib-WARNING **: In call to
g_spawn_sync(), exit status of a child process was requested but
SIGCHLD action was set to SIG_IGN and ECHILD was received by
waitpid(), so exit status can't be returned." The diagnostic
is partly wrong, as the SIGCHLD action is not set to SIG_IGN.
The real bug is a race condition between Emacs and glib: Emacs
does a waitpid (-1, ...) and reaps glib's subprocess by mistake,
so that glib can't find it. Work around the bug by invoking
waitpid only on subprocesses that Emacs itself creates.
* src/process.c (create_process, record_child_status_change):
Don't use special value -1 in pid field, as the caller now must
know the pid rather than having the callee infer it. The
inference was sometimes incorrect anyway, due to another race.
(create_process): Set new 'alive' member if child is created.
(process_status_retrieved): New function.
(record_child_status_change): Use it.
Accept negative 1st argument, which means to wait for the
processes that Emacs already knows about. Move special-case code
for DOS_NT (which lacks WNOHANG) here, from caller. Keep track of
processes that have already been waited for, by testing and
clearing new 'alive' member.
(CAN_HANDLE_MULTIPLE_CHILDREN): Remove, as record_child_status_change
now does this internally.
(handle_child_signal): Let record_child_status_change do all
the work, since we do not want to reap all exited child processes,
only the child processes that Emacs itself created.
* src/process.h (Lisp_Process): New boolean member 'alive'.
The symptom is a diagnostic "GLib-WARNING **: In call to
g_spawn_sync(), exit status of a child process was requested but
SIGCHLD action was set to SIG_IGN and ECHILD was received by
waitpid(), so exit status can't be returned." The diagnostic
is partly wrong, as the SIGCHLD action is not set to SIG_IGN.
The real bug is a race condition between Emacs and glib: Emacs
does a waitpid (-1, ...) and reaps glib's subprocess by mistake,
so that glib can't find it. Work around the bug by invoking
waitpid only on subprocesses that Emacs itself creates.
* process.c (create_process, record_child_status_change):
Don't use special value -1 in pid field, as the caller now must
know the pid rather than having the callee infer it. The
inference was sometimes incorrect anyway, due to another race.
(create_process): Set new 'alive' member if child is created.
(process_status_retrieved): New function.
(record_child_status_change): Use it.
Accept negative 1st argument, which means to wait for the
processes that Emacs already knows about. Move special-case code
for DOS_NT (which lacks WNOHANG) here, from caller. Keep track of
processes that have already been waited for, by testing and
clearing new 'alive' member.
(CAN_HANDLE_MULTIPLE_CHILDREN): Remove, as record_child_status_change
now does this internally.
(handle_child_signal): Let record_child_status_change do all
the work, since we do not want to reap all exited child processes,
only the child processes that Emacs itself created.
* process.h (Lisp_Process): New boolean member 'alive'.
Fixes: debbugs:8855
Replace all uses with calls to new setter functions.
Use INLINE_HEADER_BEGIN, INLINE_HEADER_END.
(PROCESS_INLINE): New macro.
(pset_childp): New setter function.
(pset_gnutls_cred_type) [HAVE_GNUTLS]: New setter function.
* process.c (PROCESS_INLINE):
Define to EXTERN_INLINE, so that the corresponding functions
are compiled into code.
(pset_buffer, pset_command, pset_decode_coding_system)
(pset_decoding_buf, pset_encode_coding_system)
(pset_encoding_buf, pset_filter, pset_log, pset_mark, pset_name)
(pset_plist, pset_sentinel, pset_status, pset_tty_name)
(pset_type, pset_write_queue): New setter functions.
Fixes: debbugs:12215
* src/process.h (PVAR): New macro. Adjust style.
(struct Lisp_Process): Change Lisp_Object members to INTERNAL_FIELD.
* src/print.c, src/process.c, src/sysdep.c, src/w32.c:
* src/xdisp.c: Users changed.
* admin/coccinelle/process.cocci: Semantic patch to replace direct
access to Lisp_Object members of struct Lisp_Process to PVAR.
* process.c (make_process): Initialize write_queue.
(write_queue_push, write_queue_pop): New functions.
(send_process): Use them to maintain correct ordering of process writes.
Fixes: debbugs:10815
* gnutls.c (gnutls_log_function2i): Convenience log function.
(emacs_gnutls_read): Use new log functions,
`gnutls_handshakes_tried' process member, and
`GNUTLS_EMACS_HANDSHAKES_LIMIT' to limit the number of handshake
attempts per process (connection).
* gnutls.h: Add `GNUTLS_EMACS_HANDSHAKES_LIMIT' upper limit. Add
convenience `GNUTLS_LOG2i' macro.
* process.c (make_process):
* process.h: Add integer `gnutls_handshakes_tried' member to
process struct.
to compare Lisp_Objects.
* src/gnutls.c (syms_of_gnutls): Rename Vgnutls_log_level to
global_gnutls_log_level, don't mistake it for a Lisp_Object.
(init_gnutls_functions, emacs_gnutls_handle_error): Fix up uses.
GCC 4.6.0 optimizes based on type-based alias analysis. For
example, if b is of type struct buffer * and v of type struct
Lisp_Vector *, then gcc -O2 was incorrectly assuming that &b->size
!= &v->size, and therefore "v->size = 1; b->size = 2; return
v->size;" must therefore return 1. This assumption is incorrect
for Emacs, since it type-puns struct Lisp_Vector * with many other
types. To fix this problem, this patch adds a new type struct
vector_header that documents the constraints on layout of vectors
and pseudovectors, and helps optimizing compilers not get fooled
by Emacs's type punning. It also adds the macros XSETTYPED_PVECTYPE
XSETTYPED_PSEUDOVECTOR, TYPED_PSEUDOVECTORP, for similar reasons.
* lisp.h (XVECTOR_SIZE): New convenience macro. All previous uses of
XVECTOR (foo)->size replaced to use this macro, to avoid the hassle
of writing XVECTOR (foo)->header.size.
(XVECTOR_HEADER_SIZE): New macro, for use in XSETPSEUDOVECTOR.
(XSETTYPED_PVECTYPE): New macro, specifying the name of the size
member.
(XSETPVECTYPE): Rewrite in terms of new macro.
(XSETPVECTYPESIZE): New macro, specifying both type and size.
This is a bit clearer, and further avoids the possibility of
undesirable aliasing.
(XSETTYPED_PSEUDOVECTOR): New macro, specifying the size.
(XSETPSEUDOVECTOR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR
and XVECTOR_HEADER_SIZE.
(XSETSUBR): Rewrite in terms of XSETTYPED_PSEUDOVECTOR and XSIZE,
since Lisp_Subr is a special case (no "next" field).
(ASIZE): Rewrite in terms of XVECTOR_SIZE.
(struct vector_header): New type.
(TYPED_PSEUDOVECTORP): New macro, also specifying the C type of the
object, to help avoid aliasing.
(PSEUDOVECTORP): Rewrite in terms of TYPED_PSEUDOVECTORP.
(SUBRP): Likewise, since Lisp_Subr is a special case.
* lisp.h (struct Lisp_Vector, struct Lisp_Char_Table):
(struct Lisp_Sub_Char_Table, struct Lisp_Bool_Vector):
(struct Lisp_Hash_Table): Combine first two members into a single
struct vector_header member. All uses of "size" and "next" members
changed to be "header.size" and "header.next".
* buffer.h (struct buffer): Likewise.
* font.h (struct font_spec, struct font_entity, struct font): Likewise.
* frame.h (struct frame): Likewise.
* process.h (struct Lisp_Process): Likewise.
* termhooks.h (struct terminal): Likewise.
* window.c (struct save_window_data, struct saved_window): Likewise.
* window.h (struct window): Likewise.
* alloc.c (allocate_buffer, Fmake_bool_vector, allocate_pseudovector):
Use XSETPVECTYPESIZE, not XSETPVECTYPE, to avoid aliasing problems.
* buffer.c (init_buffer_once): Likewise.
* lread.c (defsubr): Use XSETTYPED_PVECTYPE, since Lisp_Subr is a
special case.
* process.c (Fformat_network_address): Use local var for size,
for brevity.
This makes it easier for human readers (and static analyzers)
to see whether these variables are used from other modules.
* alloc.c, buffer.c, bytecode.c, callint.c, casetab.c, category.c:
* ccl.c, character.c, charset.c, cmds.c, coding.c, composite.c:
* data.c, dbusbind.c, dired.c, editfns.c, eval.c, fileio.c, fns.c:
* font.c, frame.c, fringe.c, ftfont.c, image.c, keyboard.c, keymap.c:
* lread.c, macros.c, minibuf.c, print.c, process.c, search.c:
* sound.c, syntax.c, textprop.c, window.c, xdisp.c, xfaces.c, xfns.c:
* xmenu.c, xselect.c:
Declare Q* vars static if they are not used in other modules.
* ccl.h, character.h, charset.h, coding.h, composite.h, font.h:
* frame.h, intervals.h, keyboard.h, lisp.h, process.h, syntax.h:
Remove decls of unexported vars.
* keyboard.h (EVENT_HEAD_UNMODIFIED): Remove now-unused macro.
* src/keyboard.c (input_available_signal): Declare.
(kbd_buffer_nr_stored): New function.
(kbd_buffer_store_event_hold): If kbd_buffer_nr_stored returns
more than KBD_BUFFER_SIZE/2, stop reding input (Bug#6571).
(kbd_buffer_get_event): If input is suspended and kbd_buffer_nr_stored
returns less than KBD_BUFFER_SIZE/4, resume reding input (Bug#6571).
(tty_read_avail_input): If input is on hold, return.
Don't read more that free slots in kbd_buffer (Bug#6571).
* src/process.c (kbd_is_on_hold): New variable.
(hold_keyboard_input, unhold_keyboard_input, kbd_on_hold_p):
New functions.
(wait_reading_process_output): If kbd_on_hold_p returns non-zero,
select on empty input mask.
(init_process): Initialize kbd_is_on_hold to 0.
* src/process.h (hold_keyboard_input, unhold_keyboard_input)
(kbd_on_hold_p): Declare.
* src/dbusbind.c: Include process.h.
(dbus_fd_cb, xd_find_watch_fd, xd_toggle_watch)
(xd_read_message_1): New functions.
(xd_add_watch, xd_remove_watch): Call xd_find_watch_fd. Handle
watch for both read and write.
(Fdbus_init_bus): Also register xd_toggle_watch.
(Fdbus_call_method_asynchronously, Fdbus_method_return_internal)
(Fdbus_method_error_internal, Fdbus_send_signal): Remove call
to dbus_connection_flush.
(xd_read_message): Move most of the code to xd_read_message_1.
Call xd_read_message_1 until status is COMPLETE.
* src/keyboard.c (readable_events, gobble_input): Remove DBUS code.
* src/process.c (gpm_wait_mask, max_gpm_desc): Remove.
(write_mask): New variable.
(max_input_desc): Renamed from max_keyboard_desc.
(fd_callback_info): New variable.
(add_read_fd, delete_read_fd, add_write_fd, delete_write_fd): New
functions.
(Fmake_network_process): FD_SET write_mask.
(deactivate_process): FD_CLR write_mask.
(wait_reading_process_output): Connecting renamed to Writeok.
check_connect removed. check_write is new. Remove references to
gpm. Use Writeok/check_write unconditionally (i.e. no #ifdef
NON_BLOCKING_CONNECT) instead of Connecting.
Loop over file descriptors and call callbacks in fd_callback_info
if file descriptor is ready for I/O.
(add_gpm_wait_descriptor): Just call add_keyboard_wait_descriptor.
(delete_gpm_wait_descriptor): Just call delete_keyboard_wait_descriptor.
(keyboard_bit_set): Use max_input_desc.
(add_keyboard_wait_descriptor, delete_keyboard_wait_descriptor): Remove
#ifdef subprocesses. Use max_input_desc.
(init_process): Initialize write_mask and fd_callback_info.
* src/process.h (add_read_fd, delete_read_fd, add_write_fd)
(delete_write_fd): Declare.
* configure.in: Set up GnuTLS.
* lisp/net/gnutls.el: GnuTLS glue code to set up a connection.
* src/Makefile.in (LIBGNUTLS_LIBS, LIBGNUTLS_CFLAGS, ALL_CFLAGS)
(obj, LIBES): Set up GnuTLS support.
* src/config.in: Set up GnuTLS support.
* src/emacs.c: Set up GnuTLS support and call syms_of_gnutls.
* src/gnutls.c: The source code for GnuTLS support in Emacs.
* src/gnutls.h: The GnuTLS glue for Emacs, macros and enums.
* src/process.c (make_process, Fstart_process)
(read_process_output, send_process): Set up GnuTLS support for
process input/output file descriptors.
* src/process.h: Set up GnuTLS support.
* callproc.c (synch_process_death): Make const.
(Fcall_process): Make signame const.
* emacs.c (main): Pass char[] to putenv instead of literal.
* floatfns.c (matherr): Use a const char* variable for x->name.
* font.c (font_open_by_name): Make name const.
* font.h (font_open_by_name): Make name const.
* gtkutil.c (get_utf8_string): Always return an allocated string.
Parameter is const.
(create_dialog, xg_create_one_menuitem, create_menus)
(xg_item_label_same_p, xg_update_menu_item): Free result from
get_utf8_string.
(xg_separator_p, xg_item_label_same_p): label is const.
* gtkutil.h: Replace widget_value with struct _widget_value.
(enum button_type, struct _widget_value): Remove and use the one from
keyboard.h.
* keyboard.h (_widget_value): Add defined USE_GTK. Replace Boolean
with unsigned char and XtPointer with void *.
* menu.c (Fx_popup_menu): error_name is const.
* menu.h (w32_menu_show, ns_menu_show, xmenu_show): error parameter
is const char **.
* w32menu.c (w32_menu_show):
* nsmenu.m (ns_menu_show): error parameter is const char **.
* process.h (synch_process_death): Is const char*.
* xmenu.c (Fx_popup_dialog): error_name is const char*.
(xmenu_show): error parameter is const char **. pane_string is const
char *.
(button_names): Is const char *.
(xdialog_show): error_name and pane_string is const.
* xrdb.c (get_system_app): Make path const and use char *p for non-const
char.
* xselect.c (Fx_get_atom_name): Use char empty[] instead of literal "".
* xsmfns.c (NOSPLASH_OPT): Change to char[].
(smc_save_yourself_CB): Do xstrdup on all ->type and ->name for
props. Free them at the end.
* xterm.c (emacs_class): New char[] for EMACS_CLASS.
(xim_open_dpy, xim_initialize, xim_close_dpy): Use emacs_class.
(x_term_init): Use char[] display_opt and name_opt instead of
string literal. file is const char*.
* keyboard.c (input_available_signal): Declare.
(kbd_buffer_nr_stored): New function.
(kbd_buffer_store_event_hold): If kbd_buffer_nr_stored returns
more than KBD_BUFFER_SIZE/2, stop reding input (Bug#6571).
(kbd_buffer_get_event): If input is suspended and kbd_buffer_nr_stored
returns less than KBD_BUFFER_SIZE/4, resume reding input (Bug#6571).
(tty_read_avail_input): If input is on hold, return.
Don't read more that free slots in kbd_buffer (Bug#6571).
* process.h (hold_keyboard_input, unhold_keyboard_input)
(kbd_on_hold_p): Declare.
* process.c (kbd_is_on_hold): New variable.
(hold_keyboard_input, unhold_keyboard_input, kbd_on_hold_p): New
functions.
(wait_reading_process_output): If kbd_on_hold_p returns non-zero,
select on empty input mask.
(init_process): Initialize kbd_is_on_hold to 0.
