Store and restore cursor position when copy mode is resized, from

Anindya Mukherjee.

grid.c

@@ -1285,7 +1285,7 @@ grid_reflow(struct grid *gd, u_int sx)
 
 		/*
 		 * If the line is exactly right or the first character is wider
-		 * than the targe width, just move it across unchanged.
+		 * than the target width, just move it across unchanged.
 		 */
 		if (width == sx || first > sx) {
 			grid_reflow_move(target, gl);

screen.c

@@ -49,7 +49,7 @@ struct screen_title_entry {
 TAILQ_HEAD(screen_titles, screen_title_entry);
 
 static void	screen_resize_y(struct screen *, u_int, int, u_int *);
-static void	screen_reflow(struct screen *, u_int, u_int *, u_int *);
+static void	screen_reflow(struct screen *, u_int, u_int *, u_int *, int);
 
 /* Free titles stack. */
 static void
@@ -220,27 +220,19 @@ screen_pop_title(struct screen *s)
 	}
 }
 
-/* Resize screen and return cursor position. */
+/* Resize screen with options. */
 void
 screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
-    int eat_empty, u_int *cx, u_int *cy)
+    int eat_empty, int cursor)
 {
-	u_int	tcx, tcy;
+	u_int	cx = s->cx, cy = s->grid->hsize + s->cy;
 
 	if (s->write_list != NULL)
 		screen_write_free_list(s);
 
-	if (cx == NULL)
-		cx = &tcx;
-	*cx = s->cx;
-
-	if (cy == NULL)
-		cy = т
-	*cy = s->grid->hsize + s->cy;
-
 	log_debug("%s: new size %ux%u, now %ux%u (cursor %u,%u = %u,%u)",
 	    __func__, sx, sy, screen_size_x(s), screen_size_y(s), s->cx, s->cy,
-	    *cx, *cy);
+	    cx, cy);
 
 	if (sx < 1)
 		sx = 1;
@@ -254,20 +246,21 @@ screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
 		reflow = 0;
 
 	if (sy != screen_size_y(s))
-		screen_resize_y(s, sy, eat_empty, cy);
+		screen_resize_y(s, sy, eat_empty, &cy);
 
 	if (reflow)
-		screen_reflow(s, sx, cx, cy);
+		screen_reflow(s, sx, &cx, &cy, cursor);
 
-	if (*cy >= s->grid->hsize) {
+	if (cy >= s->grid->hsize) {
-		s->cx = *cx;
+		s->cx = cx;
-		s->cy = (*cy) - s->grid->hsize;
+		s->cy = cy - s->grid->hsize;
 	} else {
 		s->cx = 0;
 		s->cy = 0;
 	}
+
 	log_debug("%s: cursor finished at %u,%u = %u,%u", __func__, s->cx,
-	    s->cy, *cx, *cy);
+	    s->cy, cx, cy);
 
 	if (s->write_list != NULL)
 		screen_write_make_list(s);
@@ -277,7 +270,7 @@ screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
 void
 screen_resize(struct screen *s, u_int sx, u_int sy, int reflow)
 {
-	screen_resize_cursor(s, sx, sy, reflow, 1, NULL, NULL);
+	screen_resize_cursor(s, sx, sy, reflow, 1, 1);
 }
 
 static void
@@ -525,17 +518,26 @@ screen_select_cell(struct screen *s, struct grid_cell *dst,
 
 /* Reflow wrapped lines. */
 static void
-screen_reflow(struct screen *s, u_int new_x, u_int *cx, u_int *cy)
+screen_reflow(struct screen *s, u_int new_x, u_int *cx, u_int *cy, int cursor)
 {
 	u_int	wx, wy;
 
-	grid_wrap_position(s->grid, *cx, *cy, &wx, &wy);
+	if (cursor) {
-	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);
+	if (cursor) {
-	log_debug("%s: new cursor is %u,%u", __func__, *cx,* cy);
+		grid_unwrap_position(s->grid, cx, cy, wx, wy);
+		log_debug("%s: new cursor is %u,%u", __func__, *cx, *cy);
+	}
+	else {
+		*cx = 0;
+		*cy = s->grid->hsize;
+	}
 }
 
 /*

tmux.h

@@ -2529,8 +2529,7 @@ 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 *,
+void	 screen_resize_cursor(struct screen *, u_int, u_int, int, int, 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 *);

window-copy.c

@@ -306,8 +306,9 @@ window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
     u_int *cy, int trim)
 {
 	struct screen		*dst;
-	u_int			 sy;
 	const struct grid_line	*gl;
+	u_int			 sy, wx, wy;
+	int			 reflow;
 
 	dst = xcalloc(1, sizeof *dst);
 
@@ -324,6 +325,12 @@ window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
 	    screen_size_x(src), sy, screen_size_x(hint),
 	    screen_hsize(src) + screen_size_y(src));
 	screen_init(dst, screen_size_x(src), sy, screen_hlimit(src));
+
+	/*
+	 * Ensure history is on for the backing grid so lines are not deleted
+	 * during resizing.
+	 */
+	dst->grid->flags |= GRID_HISTORY;
 	grid_duplicate_lines(dst->grid, 0, src->grid, 0, sy);
 
 	dst->grid->sy = sy - screen_hsize(src);
@@ -337,8 +344,19 @@ window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
 		dst->cy = src->cy;
 	}
 
+	if (cx != NULL && cy != NULL) {
+		*cx = dst->cx;
+		*cy = screen_hsize(dst) + dst->cy;
+		reflow = (screen_size_x(hint) != screen_size_x(dst));
+	}
+	else
+		reflow = 0;
+	if (reflow)
+		grid_wrap_position(dst->grid, *cx, *cy, &wx, &wy);
 	screen_resize_cursor(dst, screen_size_x(hint), screen_size_y(hint), 1,
-	    0, cx, cy);
+	    0, 0);
+	if (reflow)
+		grid_unwrap_position(dst->grid, cx, cy, wx, wy);
 
 	return (dst);
 }
@@ -392,13 +410,12 @@ window_copy_init(struct window_mode_entry *wme,
 	data->backing = window_copy_clone_screen(base, &data->screen, &cx, &cy,
 	    wme->swp != wme->wp);
 
+	data->cx = cx;
 	if (cy < screen_hsize(data->backing)) {
-		data->cx = cx;
 		data->cy = 0;
 		data->oy = screen_hsize(data->backing) - cy;
 	} else {
-		data->cx = data->backing->cx;
+		data->cy = cy - screen_hsize(data->backing);
-		data->cy = data->backing->cy;
 		data->oy = 0;
 	}
 
@@ -731,16 +748,28 @@ window_copy_resize(struct window_mode_entry *wme, u_int sx, u_int sy)
 {
 	struct window_copy_mode_data	*data = wme->data;
 	struct screen			*s = &data->screen;
+	struct grid			*gd = data->backing->grid;
+	u_int				 cx, cy, wx, wy;
+	int				 reflow;
 
 	screen_resize(s, sx, sy, 0);
-	screen_resize_cursor(data->backing, sx, sy, 1, 0, NULL, NULL);
+	cx = data->cx;
+	cy = gd->hsize + data->cy - data->oy;
+	reflow = (gd->sx != sx);
+	if (reflow)
+		grid_wrap_position(gd, cx, cy, &wx, &wy);
+	screen_resize_cursor(data->backing, sx, sy, 1, 0, 0);
+	if (reflow)
+		grid_unwrap_position(gd, &cx, &cy, wx, wy);
 
-	if (data->cy > sy - 1)
+	data->cx = cx;
-		data->cy = sy - 1;
+	if (cy < gd->hsize) {
-	if (data->cx > sx)
+		data->cy = 0;
-		data->cx = sx;
+		data->oy = gd->hsize - cy;
-	if (data->oy > screen_hsize(data->backing))
+	} else {
-		data->oy = screen_hsize(data->backing);
+		data->cy = cy - gd->hsize;
+		data->oy = 0;
+	}
 
 	window_copy_size_changed(wme);
 	window_copy_redraw_screen(wme);