Restructure shutdown flow and behavior for improved robustness * file-editor-interface.h (file_editor_interface::check_closing): Remove closing_state argument from input. * file-editor-tab.cc (file_editor_tab::_cancelled): New static variable for managing chain of file closes. (file_editor_tab::file_editor_tab): Discard _app_closing and _modal_dialog initializations. (file_editor_tab::closeEvent): Upon accepting the close event, als request tab removal. (file_editor_tab::check_modified_file): New simple routine checking for modified file if there hasn't been cancellation yet. (file_editor_tab::run_file): Remove use of _modal_dialog. (file_editor_tab::show_dialog): Add modal input setting. Remove use of _app_closing and _modal_dialog. (file_editor_tab::check_file_modified): Remove situational message for just one. If modified, call show_dialog with modal true, return QMessageBox::Cancel if anything cancelled, otherwise the user decision. (file_editor_tab::handle_file_modified_answer): Do not remove file editor tab in any case. If user cancelled, set _cancelled true. (file_editor_tab::save_file): Add "false" (non-modal) to show_dialog() call. (file_editor_tab::save_file_as): Add "false" (non-modal) to show_dialog() call. (file_editor_tab::conditional_close): Remove input argument and use of variable _app_closing. * file-editor-tab.h (file_editor_tab::conditional_close): Remove input argument. (file_editor_tab::reset_cancel): New member function declaration for managing cancellation of tab chain saves. (file_editor_tab::was_cancel): New member function for indicating any cancellation when saving modified files. (file_editor_tab::check_modified_file): New slot declaration for checking and saving file modifications. (file_editor_tab::show_dialog): Add modal option input argument. (file_editor_tab::_app_closing, file_editor_tab::_modal_dialog): Remove. (file_editor_tab::_cancelled): Add. * file-editor.cc (file_editor::file_editor): Remove _check_closing_done initialization. (file_editor::~file_editor): Remove use of _check_closing_done and check_closing(). (file_editor::check_closing): Clear cancellation history and check all files for modifications, without closing. Close all tabs and delete associated widgets if no cancellation. Remove use of _check_closing_done. (file_editor::request_close_file): Remove argument from conditional_close() function call. (file_editor::request_close_all_files): Ditto. (file_editor::request_close_other_files): Ditto. (file_editor::handle_tab_close_request): Ditto. (file_editor::handle_tab_remove_request): Add comment about deleting sender. (file_editor::add_file_editor_tab): Connect fetab_check_modified_file signal to check_modified_file slot. * file-editor.h (file_editor::fetab_check_modified_file): New signal. (file_editor::check_closing): Remove input argument. (file_editor::_check_closing_done): Remove. * main-window.cc (main_window::confirm_shutdown_octave): Rename of member function main_window::confirm_exit_octave(). Change return type to void. Set octave/qt link confirmation result then awake worker process. (main_window::exit_app): Rename of member function main_window::exit(). (main_window::closeEvent): Rather than post callback event, queue "exit" in the command buffer. (main_window::construct_octave_qt_link): Connect confirm_shutdown_signal to confirm_shutdown_octave slot. Connect exit_app_signal to exit_app slot. (main_window::exit_callback): Remove. (main_window::confirm_exit_octave): Renamed as confirm_shutdown_octave(). * main-window.h (main_window::confirm_shutdown_octave): Rename of slot confirm_exit_octave(). (main_window::exit): Renamed exit_app(). (main_window::exit_callback): Removed declaration. (main_window::confirm_exit_octave): Renamed confirm_shutdown_octave(). * octave-qt-link.cc (octave_qt_link::do_confirm_shutdown): New virtual function definition for initiating GUI shutdown and confirm exit. Worker process goes into sleep mode after issuing cross-thread signal. Return confirmation result. (octave_qt_link::do_exit): Change exit_signal to exit_app_signal. octave-qt-link.h (octave_qt_link::do_confirm_shutdown): New virtual function declaration for qt GUI. (octave_qt_link::mutex): Added. A QMutex for communicating with Qt GUI. (octave_qt_link::waitcondition): Added. For process wait. (octave_qt_link::shutdown_confirmation): Added. Store confirmation result. (octave_qt_link::_shutdown_confirm_result): Added. Confirmation result. (octave_qt_link::exit_signal): Signal renamed exit_app_signal. (octave_qt_link::confirm_shutdown_signal): Added. (octave_qt_link::exit_app_signal): Renamed of exit_signal. octave-link.h (octave_link::confirm_shutdown): Added. Access virtual function do_confirm_shutdown. (octave_link::do_confirm_shutdown): Added. Virtual function for GUI link. toplev.cc (clean_up_and_exit): Change 'retval' to 'status', as header file uses argument name 'status'. (quit): First initiate GUI shutdown via octave_link::confirm_shutdown() and if not confirmed, immediately return thereby avoiding exit sequence.

/*

Copyright (C) 1993-2015 John W. Eaton

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

*/

#if !defined (GNULIB_NAMESPACE)
#define GNULIB_NAMESPACE gnulib
#endif

#if defined (__GNUC__)
#define GCC_ATTR_DEPRECATED __attribute__ ((__deprecated__))
#define HAVE_ATTR_DEPRECATED

#define GCC_ATTR_NORETURN __attribute__ ((__noreturn__))
#define HAVE_ATTR_NORETURN

#define GCC_ATTR_UNUSED __attribute__ ((__unused__))
#define HAVE_ATTR_UNUSED
#else
#define GCC_ATTR_DEPRECATED
#define GCC_ATTR_NORETURN
#define GCC_ATTR_UNUSED
#endif

#define X_CAST(T, E) (T) (E)

#if defined (CXX_BROKEN_REINTERPRET_CAST)
#define FCN_PTR_CAST(T, E) (T) (E)
#else
#define FCN_PTR_CAST(T, E) reinterpret_cast<T> (E)
#endif

#if ! defined (HAVE_DEV_T)
typedef short dev_t;
#endif

#if ! defined (HAVE_INO_T)
typedef unsigned long ino_t;
#endif

#if defined (_MSC_VER)
#define __WIN32__
#define WIN32
/* missing parameters in macros */
#pragma warning (disable: 4003)
/* missing implementations in template instantiation */
#pragma warning (disable: 4996)
/* deprecated function names (FIXME?) */
#pragma warning (disable: 4661)
#endif

#if defined (__WIN32__) && ! defined (__CYGWIN__)
#define OCTAVE_HAVE_WINDOWS_FILESYSTEM 1
#elif defined (__CYGWIN__)
#define OCTAVE_HAVE_WINDOWS_FILESYSTEM 1
#define OCTAVE_HAVE_POSIX_FILESYSTEM 1
#else
#define OCTAVE_HAVE_POSIX_FILESYSTEM 1
#endif

/* Define to 1 if we expect to have <windows.h>, Sleep, etc. */
#if defined (__WIN32__) && ! defined (__CYGWIN__)
#define OCTAVE_USE_WINDOWS_API 1
#endif

#if defined (__APPLE__) && defined (__MACH__)
#define OCTAVE_USE_OS_X_API 1
#endif

/* sigsetjmp is a macro, not a function. */
#if defined (sigsetjmp) && defined (HAVE_SIGLONGJMP)
#define OCTAVE_HAVE_SIG_JUMP
#endif

#if defined (_UNICOS)
#define F77_USES_CRAY_CALLING_CONVENTION
#endif

#if 0
#define F77_USES_VISUAL_FORTRAN_CALLING_CONVENTION
#endif

#ifdef USE_64_BIT_IDX_T
#define SIZEOF_OCTAVE_IDX_TYPE SIZEOF_INT64_T
#else
#define SIZEOF_OCTAVE_IDX_TYPE SIZEOF_INT
#endif

/* To be able to use long doubles for 64-bit mixed arithmetics, we need
   them at least 80 bits wide and we need roundl declared in math.h.
   FIXME: Maybe substitute this by a more precise check in the future?  */
#if (SIZEOF_LONG_DOUBLE >= 10) && defined (HAVE_ROUNDL)
# define OCTAVE_INT_USE_LONG_DOUBLE
# if (SIZEOF_LONG_DOUBLE < 16 \
      && (defined __i386__ || defined __x86_64__) && defined __GNUC__)
#define OCTAVE_ENSURE_LONG_DOUBLE_OPERATIONS_ARE_NOT_TRUNCATED 1
# endif
#endif

#define OCTAVE_EMPTY_CPP_ARG

/* oct-dlldefs.h */

#if defined (_MSC_VER)
#define OCTAVE_EXPORT __declspec(dllexport)
#define OCTAVE_IMPORT __declspec(dllimport)
#else
/* All other compilers, at least for now. */
#define OCTAVE_EXPORT
#define OCTAVE_IMPORT
#endif

/* API macro for libcruft */
#ifdef CRUFT_DLL
#define CRUFT_API OCTAVE_EXPORT
#else
#define CRUFT_API OCTAVE_IMPORT
#endif

/* API macro for liboctave */
#ifdef OCTAVE_DLL
#define OCTAVE_API OCTAVE_EXPORT
#else
#define OCTAVE_API OCTAVE_IMPORT
#endif

/* API macro for libinterp */
#ifdef OCTINTERP_DLL
#define OCTINTERP_API OCTAVE_EXPORT
#else
#define OCTINTERP_API OCTAVE_IMPORT
#endif

/* API macro for libinterp/graphics */
#ifdef OCTGRAPHICS_DLL
#define OCTGRAPHICS_API OCTAVE_EXPORT
#else
#define OCTGRAPHICS_API OCTAVE_IMPORT
#endif

/* API macro for libgui */
#ifdef OCTGUI_DLL
#define OCTGUI_API OCTAVE_EXPORT
#else
#define OCTGUI_API OCTAVE_IMPORT
#endif

/* oct-types.h */

#include <stdint.h>

typedef OCTAVE_IDX_TYPE octave_idx_type;

/* Tag indicating Octave config.h has been included */
#define OCTAVE_CONFIG_INCLUDED 1