patch 8.2.4215: illegal memory access when copying lines in Visual mode

Problem:    Illegal memory access when copying lines in Visual mode.
Solution:   Adjust the Visual position after copying lines.
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 9520998..f5d93e6 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -866,6 +866,8 @@
     }
 
     appended_lines_mark(n, count);
+    if (VIsual_active)
+	check_pos(curbuf, &VIsual);
 
     msgmore((long)count);
 }