Instead of fixing with the cursor position when the copied screen is

created, resize it and let the resize/reflow code fix it up and return
it. Solves various problems with cursor position and resizing when in
copy mode. With Anindya Mukherjee.

3 files changed, 88 insertions, 62 deletions

diff --git a/screen.c b/screen.c
index 6fa0fe11..ff8b1d2e 100644
--- a/screen.c
+++ b/screen.c
@@ -48,9 +48,8 @@ struct screen_title_entry {
 };
 TAILQ_HEAD(screen_titles, screen_title_entry);
 
-static void	screen_resize_y(struct screen *, u_int);
-
-static void	screen_reflow(struct screen *, u_int);
+static void	screen_resize_y(struct screen *, u_int, int);
+static void	screen_reflow(struct screen *, u_int, u_int *, u_int *);
 
 /* Free titles stack. */
 static void
@@ -216,10 +215,23 @@ screen_pop_title(struct screen *s)
 	}
 }
 
-/* Resize screen. */
+/* Resize screen and return cursor position. */
 void
-screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
+screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
+    int eat_empty, u_int *cx, u_int *cy)
 {
+	u_int	tcx, tcy;
+
+	if (cx == NULL)
+		cx = &tcx;
+	*cx = s->cx;
+
+	if (cy == NULL)
+		cy = т
+	*cy = s->grid->hsize + s->cy;
+
+	log_debug("%s: start %u,%u (%u,%u)", __func__, s->cx, s->cy, *cx, *cy);
+
 	if (sx < 1)
 		sx = 1;
 	if (sy < 1)
@@ -232,14 +244,30 @@ screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
 		reflow = 0;
 
 	if (sy != screen_size_y(s))
-		screen_resize_y(s, sy);
+		screen_resize_y(s, sy, eat_empty);
 
 	if (reflow)
-		screen_reflow(s, sx);
+		screen_reflow(s, sx, cx, cy);
+
+	if (*cy >= s->grid->hsize) {
+		s->cx = *cx;
+		s->cy = (*cy) - s->grid->hsize;
+	} else {
+		s->cx = 0;
+		s->cy = 0;
+	}
+	log_debug("%s: finish %u,%u (%u,%u)", __func__, s->cx, s->cy, *cx, *cy);
+}
+
+/* Resize screen. */
+void
+screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
+{
+	screen_resize_cursor(s, sx, sy, reflow, 1, NULL, NULL);
 }
 
 static void
-screen_resize_y(struct screen *s, u_int sy)
+screen_resize_y(struct screen *s, u_int sy, int eat_empty)
 {
 	struct grid	*gd = s->grid;
 	u_int		 needed, available, oldy, i;
@@ -264,14 +292,16 @@ screen_resize_y(struct screen *s, u_int sy)
 		needed = oldy - sy;
 
 		/* Delete as many lines as possible from the bottom. */
-		available = oldy - 1 - s->cy;
-		if (available > 0) {
-			if (available > needed)
-				available = needed;
-			grid_view_delete_lines(gd, oldy - available, available,
-			    8);
+		if (eat_empty) {
+			available = oldy - 1 - s->cy;
+			if (available > 0) {
+				if (available > needed)
+					available = needed;
+				grid_view_delete_lines(gd, oldy - available,
+				    available, 8);
+			}
+			needed -= available;
 		}
-		needed -= available;
 
 		/*
 		 * Now just increase the history size, if possible, to take
@@ -287,7 +317,6 @@ screen_resize_y(struct screen *s, u_int sy)
 				available = needed;
 			grid_view_delete_lines(gd, 0, available, 8);
 		}
-		s->cy -= needed;
 	}
 
 	/* Resize line array. */
@@ -307,7 +336,6 @@ screen_resize_y(struct screen *s, u_int sy)
 				available = needed;
 			gd->hscrolled -= available;
 			gd->hsize -= available;
-			s->cy += available;
 		} else
 			available = 0;
 		needed -= available;
@@ -482,25 +510,17 @@ screen_select_cell(struct screen *s, struct grid_cell *dst,
 
 /* Reflow wrapped lines. */
 static void
-screen_reflow(struct screen *s, u_int new_x)
+screen_reflow(struct screen *s, u_int new_x, u_int *cx, u_int *cy)
 {
-	u_int	cx = s->cx, cy = s->grid->hsize + s->cy, wx, wy;
+	u_int	wx, wy;
 
-	grid_wrap_position(s->grid, cx, cy, &wx, &wy);
-	log_debug("%s: cursor %u,%u is %u,%u", __func__, cx, cy, wx, wy);
+	grid_wrap_position(s->grid, *cx, *cy, &wx, &wy);
+	log_debug("%s: cursor %u,%u is %u,%u", __func__, *cx, *cy, wx, wy);
 
 	grid_reflow(s->grid, new_x);
 
-	grid_unwrap_position(s->grid, &cx, &cy, wx, wy);
-	log_debug("%s: new cursor is %u,%u", __func__, cx, cy);
-
-	if (cy >= s->grid->hsize) {
-		s->cx = cx;
-		s->cy = cy - s->grid->hsize;
-	} else {
-		s->cx = 0;
-		s->cy = 0;
-	}
+	grid_unwrap_position(s->grid, cx, cy, wx, wy);
+	log_debug("%s: new cursor is %u,%u", __func__, *cx,* cy);
 }
 
 /*
diff --git a/tmux.h b/tmux.h
index 260891b2..73b6b941 100644
--- a/tmux.h
+++ b/tmux.h
@@ -2437,6 +2437,8 @@ void	 screen_set_path(struct screen *, const char *);
 void	 screen_push_title(struct screen *);
 void	 screen_pop_title(struct screen *);
 void	 screen_resize(struct screen *, u_int, u_int, int);
+void	 screen_resize_cursor(struct screen *, u_int, u_int, int, int, u_int *,
+	     u_int *);
 void	 screen_set_selection(struct screen *, u_int, u_int, u_int, u_int,
 	     u_int, int, struct grid_cell *);
 void	 screen_clear_selection(struct screen *);
diff --git a/window-copy.c b/window-copy.c
index f6f29f9a..2b42eb2a 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -298,30 +298,33 @@ window_copy_scroll_timer(__unused int fd, __unused short events, void *arg)
 }
 
 static struct screen *
-window_copy_clone_screen(struct screen *src, struct screen *hint)
+window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
+    u_int *cy)
 {
-	struct screen			*dst;
-	struct screen_write_ctx		 ctx;
-	u_int				 dy, sy;
+	struct screen		*dst;
+	u_int			 sy;
+	const struct grid_line	*gl;
 
 	dst = xcalloc(1, sizeof *dst);
 
 	sy = screen_hsize(src) + screen_size_y(src);
-	if (screen_size_y(hint) > sy)
-		dy = screen_size_y(hint);
-	else
-		dy = sy;
-	screen_init(dst, screen_size_x(src), dy, src->grid->hlimit);
-
-	grid_duplicate_lines(dst->grid, 0, src->grid, 0, sy);
-	if (screen_size_y(hint) < sy) {
-		dst->grid->sy = screen_size_y(hint);
-		dst->grid->hsize = sy - screen_size_y(hint);
+	while (sy > screen_hsize(src)) {
+		gl = grid_peek_line(src->grid, sy - 1);
+		if (gl->cellused != 0)
+			break;
+		sy--;
 	}
+	screen_init(dst, screen_size_x(src), sy, screen_hlimit(src));
+	grid_duplicate_lines(dst->grid, 0, src->grid, 0, sy);
 
-	screen_write_start(&ctx, NULL, dst);
-	screen_write_cursormove(&ctx, 0, dst->grid->sy + sy - dy - 1, 0);
-	screen_write_stop(&ctx);
+	dst->grid->sy = sy - screen_hsize(src);
+	dst->grid->hsize = screen_hsize(src);
+	dst->grid->hscrolled = src->grid->hscrolled;
+	dst->cx = src->cx;
+	dst->cy = src->cy;
+
+	screen_resize_cursor(dst, screen_size_x(hint), screen_size_y(hint), 1,
+	    0, cx, cy);
 
 	return (dst);
 }
@@ -370,22 +373,22 @@ window_copy_init(struct window_mode_entry *wme,
 {
 	struct window_pane		*wp = wme->swp;
 	struct window_copy_mode_data	*data;
+	struct screen			*base = &wp->base;
 	struct screen_write_ctx		 ctx;
-	u_int				 i;
+	u_int				 i, cx, cy;
 
 	data = window_copy_common_init(wme);
-	data->backing = window_copy_clone_screen(&wp->base, &data->screen);
-
-	data->cx = wp->base.cx;
-	if (data->cx > screen_size_x(&data->screen) - 1)
-		data->cx = screen_size_x(&data->screen) - 1;
+	data->backing = window_copy_clone_screen(base, &data->screen, &cx, &cy);
 
-	data->cy = screen_hsize(&wp->base) + wp->base.cy;
-	if (data->cy < screen_hsize(data->backing)) {
-		data->oy = screen_hsize(data->backing) - data->cy;
+	if (cy < screen_hsize(data->backing)) {
+		data->cx = cx;
 		data->cy = 0;
-	} else
-		data->cy -= screen_hsize(data->backing);
+		data->oy = screen_hsize(data->backing) - cy;
+	} else {
+		data->cx = data->backing->cx;
+		data->cy = data->backing->cy;
+		data->oy = 0;
+	}
 
 	data->scroll_exit = args_has(args, 'e');
 	data->hide_position = args_has(args, 'H');
@@ -697,8 +700,8 @@ window_copy_resize(struct window_mode_entry *wme, u_int sx, u_int sy)
 	struct screen_write_ctx	 	 ctx;
 	int				 search;
 
-	screen_resize(s, sx, sy, 1);
-	screen_resize(data->backing, sx, sy, 1);
+	screen_resize(s, sx, sy, 0);
+	screen_resize_cursor(data->backing, sx, sy, 1, 0, NULL, NULL);
 
 	if (data->cy > sy - 1)
 		data->cy = sy - 1;
@@ -2024,7 +2027,8 @@ window_copy_cmd_refresh_from_pane(struct window_copy_cmd_state *cs)
 
 	screen_free(data->backing);
 	free(data->backing);
-	data->backing = window_copy_clone_screen(&wp->base, &data->screen);
+	data->backing = window_copy_clone_screen(&wp->base, &data->screen, NULL,
+	    NULL);
 
 	return (WINDOW_COPY_CMD_REDRAW);
 }