patch 8.1.0158: GUI: input() fails if CTRL-C was pressed before

Problem:    GUI: input() fails if CTRL-C was pressed before. (Michael Naumann)
Solution:   call vpeekc() to drop the CTRL-C from the input stream.

src/ex_docmd.c

@@ -9157,6 +9157,11 @@ do_sleep(long msec)
 	parse_queued_messages();
 #endif
     }
+
+    // If CTRL-C was typed to interrupt the sleep, drop the CTRL-C from the
+    // input buffer, otherwise a following call to input() fails.
+    if (got_int)
+	(void)vpeekc();
 }
 
     static void

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    158,
 /**/
     157,
 /**/