xC: use the correct way of resetting libedit

The only remaining major annoyance is incremental search
seemingly not giving back control.

xC.c

@@ -761,7 +761,6 @@ struct input_el
 {
 	struct input super;                 ///< Parent class
 	EditLine *editline;                 ///< The EditLine object
-	FILE *null;                         ///< Output redirect
 
 	bool active;                        ///< Are we a thing?
 	char *prompt;                       ///< The prompt we use
@@ -1027,39 +1026,16 @@ input_el__restore (struct input_el *self)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-// XXX: Editline keeping its own history position (look for "eventno" there).
-//   Invoking ed-next-history through our bind from app_editline_init() seems
-//   like the only viable hack to get consistent history behaviour.
+// Editline keeping its own history position (look for "eventno" there).
+// This is the only sane way of resetting it.
 static void
-input_el__bottom (struct input_el *self)
+input_el__start_over (struct input_el *self)
 {
-	// First, we need to redirect output to avoid ringing the terminal bell.
-	// Assuming that the line has just been erased but not redisplayed
-	// by caller, we need to CC_REFRESH first.
-	input_el__redisplay (self);
+	wchar_t x[] = { L'g' & 31, 0 };
+	el_wpush (self->editline, x);
 
-	FILE *out = NULL;
-	el_wget (self->editline, EL_GETFP, 1, &out);
-	el_wset (self->editline, EL_SETFP, 1, self->null);
-
-	// Invoke hist_get() to make the history pointer's cursor match "eventno".
-	int down = 1, dummy_count = 0;
-	el_wpush (self->editline, L"\x1bn");
+	int dummy_count = 0;
 	(void) el_wgets (self->editline, &dummy_count);
-
-	// It doesn't seem like we can just retrieve the position.
-	HistEventW ev;
-	while (!history_w (self->current->history, &ev, H_PREV))
-		down++;
-	while (down--)
-	{
-		el_wpush (self->editline, L"\x1bn");
-		(void) el_wgets (self->editline, &dummy_count);
-	}
-
-	// Otherwise input may survive our erasing, reproducer: a^Rb^[^N
-	input_el_clear_line (self);
-	el_wset (self->editline, EL_SETFP, 1, out);
 }
 
 static void
@@ -1075,7 +1051,7 @@ input_el_buffer_switch (void *input, input_buffer_t input_buffer)
 
 	self->current = buffer;
 	el_wset (self->editline, EL_HIST, history, buffer->history);
-	input_el__bottom (self);
+	input_el__start_over (self);
 	input_el__restore_buffer (self, buffer);
 }
 
@@ -1170,7 +1146,6 @@ input_el_destroy (void *input)
 		free (iter->help);
 		ffi_closure_free (iter);
 	}
-	fclose (self->null);
 	free (self->prompt);
 	free (self);
 }
@@ -1184,7 +1159,6 @@ input_el_new (void)
 {
 	struct input_el *self = xcalloc (1, sizeof *self);
 	self->super.vtable = &input_el_vtable;
-	self->null = fopen ("/dev/null", "w");
 	return &self->super;
 }
 
@@ -13947,8 +13921,6 @@ on_editline_return (EditLine *editline, int key)
 
 	const LineInfoW *info = el_wline (editline);
 	int len = info->lastchar - info->buffer;
-	int point = info->cursor - info->buffer;
-
 	wchar_t *line = calloc (sizeof *info->buffer, len + 1);
 	memcpy (line, info->buffer, sizeof *info->buffer * len);
 
@@ -13965,9 +13937,8 @@ on_editline_return (EditLine *editline, int key)
 		xstrndup (info_mb->buffer, info_mb->lastchar - info_mb->buffer));
 	poller_idle_set (&ctx->input_event);
 
-	el_cursor (editline, len - point);
-	el_wdeletestr (editline, len);
-	input_el__bottom (self);
+	// We must invoke ch_reset(), which isn't done for us with EL_UNBUFFERED.
+	input_el__start_over (self);
 	return CC_REFRESH;
 }
 
@@ -13992,8 +13963,12 @@ app_editline_init (struct input_el *self)
 	CALL_ (input, bind_control, 'w', "ed-delete-prev-word");
 	// Just what are you doing?
 	CALL_ (input, bind_control, 'u', "vi-kill-line-prev");
+
 	// See input_el__redisplay(), functionally important
 	CALL_ (input, bind_control, 'q', "ed-redisplay");
+	// This is what buffered el_wgets() does, functionally important;
+	// perhaps it could be bound somewhere more appropriate
+	CALL_ (input, bind_control, 'g', "ed-start-over");
 
 	// We need to hide the prompt and input first
 	CALL_ (input, bind, "\r", "send-line");