GTK: SIGTERM/SIGHUP always terminates the program and dumps recovery files

* SIGTERM used to insert the ^KCLOSE key macro.
  However with the default ^KCLOSE macro, which inserts `EX`,
  this may fail to terminate the editor if buffers are modified.
  If the process is consequently killed by a non-ignorable signal,
  we may still loose data.
* SIGTERM is used to gracefully shut down, so we now always terminate.
  Since we have recovery files, they are now dumped before terminating.
  This makes sure that recovery files are more up-to-date during
  unexpected but gracefull terminations.
* The same functionality is planned on Curses, but requires more fundamental
  changes (TODO).

8 files changed, 61 insertions, 39 deletions

diff --git a/doc/sciteco.1.in b/doc/sciteco.1.in
index e47ca93..83dba44 100644
--- a/doc/sciteco.1.in
+++ b/doc/sciteco.1.in
@@ -425,13 +425,12 @@ Note that this signal can usually also be generated when pressing
 .TP
 .SCITECO_TOPIC "SIGTERM"
 .B SIGTERM
+.TQ
+.SCITECO_TOPIC "SIGHUP"
+.B SIGHUP
 Try to gracefully shut down \*(ST.
-In batch mode this only interrupts the currently running macro
-similar to \fBSIGINT\fP causing \*(ST to exit.
-If technically possible, user interfaces will additionally
-process \fBSIGTERM\fP in interactive mode as if the \fICLOSE\fP
-function key has been pressed, which will result in unconditional
-program termination or user-programmed behaviour.
+If technically possible, this will immediately dump recovery
+files unless recovery file dumping is disabled (\(lq0,6EJ\(rq).
 .
 .
 .SH FILES
diff --git a/src/core-commands.c b/src/core-commands.c
index 528fa64..2dc1da7 100644
--- a/src/core-commands.c
+++ b/src/core-commands.c
@@ -2194,6 +2194,8 @@ teco_state_ecommand_flags(teco_machine_main_t *ctx, GError **error)
  * They are removed automatically when no longer required,
  * but may be left around when the \*(ST crashes or terminates
  * unexpectedly.
+ * During graceful shutdowns (\fBSIGTERM\fP etc.) recovery
+ * files may be dumped immediately even before the interval expires.
  * After changing the interval, the new value may become
  * active only after the previous interval expires.
  * Recovery files are not dumped in batch mode.
diff --git a/src/interface-curses/interface.c b/src/interface-curses/interface.c
index b49540b..569b13a 100644
--- a/src/interface-curses/interface.c
+++ b/src/interface-curses/interface.c
@@ -125,7 +125,8 @@ teco_console_ctrl_handler(DWORD type)
 {
 	switch (type) {
 	case CTRL_C_EVENT:
-		teco_interrupted = TRUE;
+	case CTRL_BREAK_EVENT:
+		teco_interrupted = TECO_INTERRUPTED;
 		return TRUE;
 	}
 
@@ -1022,7 +1023,7 @@ teco_interface_getch(gboolean widechar)
 			case KEY_ENTER:
 				return '\n';
 			case TECO_CTL_KEY('C'):
-				teco_interrupted = TRUE;
+				teco_interrupted = TECO_INTERRUPTED;
 				/* fall through */
 			case TECO_CTL_KEY('D'):
 				/* emulates EOF on stdin */
@@ -1799,7 +1800,7 @@ teco_interface_popup_clear(void)
 gboolean
 teco_interface_is_interrupted(void)
 {
-	return teco_interrupted != FALSE;
+	return teco_interrupted == TECO_INTERRUPTED;
 }
 
 #else /* !CURSES_TTY && !PDCURSES_WINCON && !NCURSES_WIN32 */
@@ -1818,7 +1819,7 @@ teco_interface_is_interrupted(void)
 {
 	if (!teco_interface.input_pad)
 		/* batch mode */
-		return teco_interrupted != FALSE;
+		return teco_interrupted == TECO_INTERRUPTED;
 
 	/*
 	 * NOTE: wgetch() is configured to be nonblocking.
@@ -1833,7 +1834,7 @@ teco_interface_is_interrupted(void)
 		                  GINT_TO_POINTER(key));
 	}
 
-	return teco_interrupted != FALSE;
+	return teco_interrupted == TECO_INTERRUPTED;
 }
 
 #endif
@@ -2122,7 +2123,7 @@ teco_interface_blocking_getch(void)
 	gint key = wgetch(teco_interface.input_pad);
 	teco_memory_start_limiting();
 	/* allow asynchronous interruptions on <CTRL/C> */
-	teco_interrupted = FALSE;
+	teco_interrupted = TECO_NORMAL;
 	wtimeout(teco_interface.input_pad, 0);
 #if defined(CURSES_TTY) || defined(PDCURSES_WINCON) || defined(NCURSES_WIN32)
 	noraw(); /* FIXME: necessary because of NCURSES_WIN32 bug */
diff --git a/src/interface-gtk/interface.c b/src/interface-gtk/interface.c
index 1540245..a31790f 100644
--- a/src/interface-gtk/interface.c
+++ b/src/interface-gtk/interface.c
@@ -78,7 +78,7 @@ static void teco_interface_popup_clicked_cb(GtkWidget *popup, gchar *str, gulong
                                             gpointer user_data);
 static gboolean teco_interface_window_delete_cb(GtkWidget *widget, GdkEventAny *event,
                                                 gpointer user_data);
-static gboolean teco_interface_sigterm_handler(gpointer user_data) G_GNUC_UNUSED;
+static gboolean teco_interface_termination_handler(gpointer user_data) G_GNUC_UNUSED;
 static gchar teco_interface_get_ansi_key(GdkEventKey *event);
 
 #define TECO_UNNAMED_FILE	"(Unnamed)"
@@ -477,7 +477,7 @@ teco_interface_getch_process_event(GdkEvent *event, teco_int_t *cp)
 			*cp = TECO_CTL_KEY(g_ascii_toupper(*cp));
 			switch (*cp) {
 			case TECO_CTL_KEY('C'):
-				teco_interrupted = TRUE;
+				teco_interrupted = TECO_INTERRUPTED;
 				/* fall through */
 			case TECO_CTL_KEY('D'):
 				/* emulates EOF on stdin */
@@ -823,7 +823,7 @@ teco_interface_is_interrupted(void)
 {
 	if (!gtk_main_level())
 		/* batch mode */
-		return teco_interrupted != FALSE;
+		return teco_interrupted == TECO_INTERRUPTED;
 
 	/*
 	 * By polling only every TECO_POLL_INTERVAL microseconds
@@ -833,11 +833,11 @@ teco_interface_is_interrupted(void)
 	guint64 now_ts = g_get_monotonic_time();
 
 	if (G_LIKELY(last_poll_ts+TECO_POLL_INTERVAL > now_ts))
-		return teco_interrupted != FALSE;
+		return teco_interrupted == TECO_INTERRUPTED;
 	last_poll_ts = now_ts;
 
 	gtk_main_iteration_do(FALSE);
-	return teco_interrupted != FALSE;
+	return teco_interrupted == TECO_INTERRUPTED;
 }
 
 void
@@ -1298,13 +1298,12 @@ teco_interface_event_loop(GError **error)
 #endif
 
 	/*
-	 * SIGTERM emulates the "Close" key just like when
-	 * closing the window if supported by this version of glib.
-	 * Note that this replaces SciTECO's default SIGTERM handler
-	 * so it will additionally raise(SIGINT).
+	 * SIGTERM and SIGHUP terminate the program, but will
+	 * dump recovery files first (if enabled).
 	 */
 #ifdef G_OS_UNIX
-	g_unix_signal_add(SIGTERM, teco_interface_sigterm_handler, NULL);
+	g_unix_signal_add(SIGTERM, teco_interface_termination_handler, NULL);
+	g_unix_signal_add(SIGHUP, teco_interface_termination_handler, NULL);
 #endif
 
 	/* the interval might have been changed in the profile */
@@ -1428,7 +1427,7 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 			 * If the execution thread is currently blocking,
 			 * the key is delivered like an ordinary key press.
 			 */
-			teco_interrupted = TRUE;
+			teco_interrupted = TECO_INTERRUPTED;
 		else
 			g_queue_push_tail(teco_interface.event_queue,
 			                  gdk_event_copy(event));
@@ -1469,7 +1468,7 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 		const teco_view_t *last_view = teco_interface_current_view;
 		sptr_t last_vpos = teco_interface_ssm(SCI_GETFIRSTVISIBLELINE, 0, 0);
 
-		teco_interrupted = FALSE;
+		teco_interrupted = TECO_NORMAL;
 		switch (event->type) {
 		case GDK_KEY_PRESS:
 			teco_interface_handle_key_press(&event->key, &error);
@@ -1486,7 +1485,7 @@ teco_interface_input_cb(GtkWidget *widget, GdkEvent *event, gpointer user_data)
 		default:
 			g_assert_not_reached();
 		}
-		teco_interrupted = FALSE;
+		teco_interrupted = TECO_NORMAL;
 
 		teco_interface_update(teco_interface_current_view != last_view);
 		/* always expand folds, even after mouse clicks */
@@ -1596,16 +1595,23 @@ teco_interface_window_delete_cb(GtkWidget *widget, GdkEventAny *event, gpointer
 }
 
 static gboolean
-teco_interface_sigterm_handler(gpointer user_data)
+teco_interface_termination_handler(gpointer user_data)
 {
+	teco_interface_msg(TECO_MSG_WARNING, "Received termination signal - dumping recovery files");
+	teco_interrupted = TECO_TERMINATED;
+
 	/*
-	 * Similar to window deletion - emulate "close" key press.
+	 * This may be an emergency shutdown or another kind of
+	 * termination that we cannot ignore, so better dump
+	 * recovery files before terminating.
 	 */
-	GtkWidget *widget = teco_interface.window;
+	if (teco_ring_recovery_interval != 0)
+		teco_ring_dump_recovery();
 
-	g_autoptr(GdkEvent) close_event = gdk_event_new(GDK_KEY_PRESS);
-	close_event->key.window = gtk_widget_get_parent_window(widget);
-	close_event->key.keyval = GDK_KEY_Close;
+	/*
+	 * Otherwise we terminate and clean up as if by `-EX`.
+	 */
+	gtk_main_quit();
 
-	return teco_interface_input_cb(widget, close_event, NULL);
+	return G_SOURCE_REMOVE;
 }
diff --git a/src/main.c b/src/main.c
index 8bc02f1..33ab26f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -66,12 +66,15 @@
 teco_int_t teco_ed = TECO_ED_AUTOEOL;
 
 /**
- * Whether there was an asyncronous interruption (usually after pressing CTRL+C).
+ * Whether there was an asynchronous interruption (usually after
+ * pressing CTRL+C) or termination (SIGTERM).
  * However you should always use teco_interface_is_interrupted(),
  * to check for interruptions because of its side effects.
  * This variable is safe to set to TRUE from signal handlers and threads.
+ *
+ * This is a teco_interrupted_t.
  */
-volatile sig_atomic_t teco_interrupted = FALSE;
+volatile sig_atomic_t teco_interrupted = TECO_NORMAL;
 
 /*
  * FIXME: Move this into file-utils.c?
@@ -346,7 +349,7 @@ teco_initialize_environment(void)
 static void
 teco_sigint_handler(int signal)
 {
-	teco_interrupted = TRUE;
+	teco_interrupted = TECO_INTERRUPTED;
 }
 
 #ifdef G_OS_WIN32
@@ -386,7 +389,6 @@ main(int argc, char **argv)
 #endif
 
 	signal(SIGINT, teco_sigint_handler);
-	signal(SIGTERM, teco_sigint_handler);
 
 	/*
 	 * Important for Unicode handling in curses and glib.
diff --git a/src/ring.c b/src/ring.c
index 8bb825c..9feb444 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -143,7 +143,12 @@ teco_buffer_save(teco_buffer_t *ctx, const gchar *filename, GError **error)
 static inline void
 teco_buffer_free(teco_buffer_t *ctx)
 {
-	if (ctx->state > TECO_BUFFER_DIRTY_NO_DUMP) {
+	/*
+	 * During graceful, but unexpected shutdowns (SIGTERM etc.),
+	 * we must preserve the recovery files.
+	 */
+	if (ctx->state > TECO_BUFFER_DIRTY_NO_DUMP &&
+	    teco_interrupted != TECO_TERMINATED) {
 		g_autofree gchar *filename_recovery = teco_buffer_get_recovery(ctx);
 		g_unlink(filename_recovery);
 	}
@@ -317,7 +322,8 @@ guint teco_ring_recovery_interval = 2*60;
 /**
  * Create recovery files for all dirty buffers.
  *
- * Should be called by the interface every teco_ring_recovery_interval seconds.
+ * Should be called by the interface every teco_ring_recovery_interval seconds
+ * or before graceful terminations (SIGTERM etc.).
  * This does not generate or expect undo tokens, so it can be called
  * even when idlying.
  */
diff --git a/src/sciteco.h b/src/sciteco.h
index 16dba69..88078c2 100644
--- a/src/sciteco.h
+++ b/src/sciteco.h
@@ -109,6 +109,12 @@ teco_default_codepage(void)
 	return teco_ed & TECO_ED_DEFAULT_ANSI ? SC_CHARSET_ANSI : SC_CP_UTF8;
 }
 
+typedef enum {
+	TECO_NORMAL = 0,
+	TECO_INTERRUPTED,
+	TECO_TERMINATED
+} teco_interrupted_t;
+
 /* in main.c */
 extern volatile sig_atomic_t teco_interrupted;
 
diff --git a/src/spawn.c b/src/spawn.c
index 61718fd..716bafa 100644
--- a/src/spawn.c
+++ b/src/spawn.c
@@ -869,7 +869,7 @@ teco_spawn_idle_cb(gpointer user_data)
 {
 	if (G_LIKELY(!teco_interface_is_interrupted()))
 		return G_SOURCE_CONTINUE;
-	teco_interrupted = FALSE;
+	teco_interrupted = TECO_NORMAL;
 
 	/*
 	 * The first CTRL+C will try to gracefully terminate the process.