patch 8.0.0103
Problem:    May not process channel readahead. (skywind)
Solution:   If there is readahead don't block on input.
diff --git a/src/misc2.c b/src/misc2.c
index 9fa11e3..7f23c43 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -6264,7 +6264,7 @@
 }
 #endif
 
-#ifdef ELAPSED_TIMEVAL  /* proto is defined in vim.h */
+#ifdef ELAPSED_TIMEVAL  /* no PROTO here, proto is defined in vim.h */
 /*
  * Return time in msec since "start_tv".
  */
@@ -6288,9 +6288,6 @@
 {
     DWORD	now = GetTickCount();
 
-    if (now < start_tick)
-	/* overflow */
-	return (long)now;
     return (long)now - (long)start_tick;
 }
 #endif