Make sure the cursor position is still on screen after we have trimmed

empty lines. Also improve some log messages.

3 files changed, 16 insertions, 5 deletions

diff --git a/screen.c b/screen.c
index ff8b1d2e..d9d1aa09 100644
--- a/screen.c
+++ b/screen.c
@@ -230,7 +230,9 @@ screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
 		cy = т
 	*cy = s->grid->hsize + s->cy;
 
-	log_debug("%s: start %u,%u (%u,%u)", __func__, s->cx, s->cy, *cx, *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);
 
 	if (sx < 1)
 		sx = 1;
@@ -256,7 +258,8 @@ screen_resize_cursor(struct screen *s, u_int sx, u_int sy, int reflow,
 		s->cx = 0;
 		s->cy = 0;
 	}
-	log_debug("%s: finish %u,%u (%u,%u)", __func__, s->cx, s->cy, *cx, *cy);
+	log_debug("%s: cursor finished at %u,%u = %u,%u", __func__, s->cx,
+	    s->cy, *cx, *cy);
 }
 
 /* Resize screen. */
diff --git a/tmux.h b/tmux.h
index a5dead04..b791f5af 100644
--- a/tmux.h
+++ b/tmux.h
@@ -79,7 +79,7 @@ struct winlink;
 #define NAME_INTERVAL 500000
 
 /* Maximum size of data to hold from a pane. */
-#define READ_SIZE 4096
+#define READ_SIZE 8192
 
 /* Default pixel cell sizes. */
 #define DEFAULT_XPIXEL 16
diff --git a/window-copy.c b/window-copy.c
index bdf2c148..45a47675 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -314,14 +314,22 @@ window_copy_clone_screen(struct screen *src, struct screen *hint, u_int *cx,
 			break;
 		sy--;
 	}
+	log_debug("%s: target screen is %ux%u, source %ux%u", __func__,
+	    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));
 	grid_duplicate_lines(dst->grid, 0, src->grid, 0, sy);
 
 	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;
+	if (src->cy > dst->grid->sy - 1) {
+		dst->cx = 0;
+		dst->cy = dst->grid->sy - 1;
+	} else {
+		dst->cx = src->cx;
+		dst->cy = src->cy;
+	}
 
 	screen_resize_cursor(dst, screen_size_x(hint), screen_size_y(hint), 1,
 	    0, cx, cy);