choose-tree: Reset top when toggling items

When choose-tree is told to expand/collapse items (especially when first
rendering collapsed to just show sessions), ensure that in addition to
setting the selected item, that the item itself appears on the bottom of the
screen, rather than off screen.

This was causing rendering glitches when a very small tmux window tried to
render a list of items in choose-tree much larger than itself, and the
selected item appeared off screen, and didn't show the selection until the
selection had wrapped around to the top of the screen.

2 files changed, 17 insertions, 9 deletions

diff --git a/cmd-choose-tree.c b/cmd-choose-tree.c
index a9b6ffbc..2fe6e171 100644
--- a/cmd-choose-tree.c
+++ b/cmd-choose-tree.c
@@ -228,7 +228,6 @@ windows_only:
 	free(final_win_template_last);
 
 	window_choose_ready(wl->window->active, cur_win, NULL);
-	window_choose_collapse_all(wl->window->active);
 
 	if (args_has(args, 'u')) {
 		window_choose_expand_all(wl->window->active);
diff --git a/window-choose.c b/window-choose.c
index 5ed85f0e..572581a5 100644
--- a/window-choose.c
+++ b/window-choose.c
@@ -81,6 +81,7 @@ int     window_choose_key_index(struct window_choose_mode_data *, u_int);
 int     window_choose_index_key(struct window_choose_mode_data *, int);
 void	window_choose_prompt_input(enum window_choose_input_type,
 	    const char *, struct window_pane *, int);
+void	window_choose_reset_top(struct window_pane *, u_int);
 
 void
 window_choose_add(struct window_pane *wp, struct window_choose_data *wcd)
@@ -107,8 +108,17 @@ window_choose_set_current(struct window_pane *wp, u_int cur)
 	struct screen			*s = &data->screen;
 
 	data->selected = cur;
-	if (data->selected > screen_size_y(s) - 1)
-		data->top = ARRAY_LENGTH(&data->list) - screen_size_y(s);
+	window_choose_reset_top(wp, screen_size_y(s));
+}
+
+void
+window_choose_reset_top(struct window_pane *wp, u_int sy)
+{
+	struct window_choose_mode_data	*data = wp->modedata;
+
+	data->top = 0;
+	if (data->selected > sy - 1)
+		data->top = data->selected - (sy - 1);
 
 	window_choose_redraw_screen(wp);
 }
@@ -277,10 +287,7 @@ window_choose_resize(struct window_pane *wp, u_int sx, u_int sy)
 	struct window_choose_mode_data	*data = wp->modedata;
 	struct screen			*s = &data->screen;
 
-	data->top = 0;
-	if (data->selected > sy - 1)
-		data->top = data->selected - (sy - 1);
-
+	window_choose_reset_top(wp, sy);
 	screen_resize(s, sx, sy, 0);
 	window_choose_redraw_screen(wp);
 }
@@ -373,6 +380,7 @@ window_choose_collapse_all(struct window_pane *wp)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	struct window_choose_mode_item	*item;
+	struct screen			*scr = &data->screen;
 	struct session			*s, *chosen;
 	u_int				 i;
 
@@ -391,7 +399,7 @@ window_choose_collapse_all(struct window_pane *wp)
 		if (item->wcd->type & TREE_SESSION)
 			data->selected = i;
 	}
-	window_choose_redraw_screen(wp);
+	window_choose_reset_top(wp, screen_size_y(scr));
 }
 
 void
@@ -399,6 +407,7 @@ window_choose_expand_all(struct window_pane *wp)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	struct window_choose_mode_item	*item;
+	struct screen			*scr = &data->screen;
 	struct session			*s;
 	u_int				 i;
 
@@ -414,7 +423,7 @@ window_choose_expand_all(struct window_pane *wp)
 		}
 	}
 
-	window_choose_redraw_screen(wp);
+	window_choose_reset_top(wp, screen_size_y(scr));
 }
 
 void