patch 9.0.0592: display not cleared when scrolling back in messages
Problem: Display not cleared when scrolling back in messages, a background
color is set and t_ut is empty.
Solution: Clear to the end of the display if needed. (closes #8973)
diff --git a/src/proto/screen.pro b/src/proto/screen.pro
index 2b77537..d53955e 100644
--- a/src/proto/screen.pro
+++ b/src/proto/screen.pro
@@ -30,7 +30,7 @@
int screen_valid(int doclear);
void screenalloc(int doclear);
void free_screenlines(void);
-void screenclear(void);
+int screenclear(void);
void redraw_as_cleared(void);
void line_was_clobbered(int screen_lnum);
int can_clear(char_u *p);