updated for version 7.3.535
Problem:    Many #ifdefs for MB_MAXBYTES.
Solution:   Also define MB_MAXBYTES without the +multi_byte feature.  Fix
            places where the buffer didn't include space for a NUL byte.
diff --git a/src/screen.c b/src/screen.c
index fd74707..e5a5b19 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -6621,16 +6621,17 @@
     int	    row, col;
     int	    attr;
 {
-#ifdef FEAT_MBYTE
     char_u	buf[MB_MAXBYTES + 1];
 
-    buf[(*mb_char2bytes)(c, buf)] = NUL;
-#else
-    char_u	buf[2];
-
-    buf[0] = c;
-    buf[1] = NUL;
+#ifdef FEAT_MBYTE
+    if (has_mbyte)
+	buf[(*mb_char2bytes)(c, buf)] = NUL;
+    else
 #endif
+    {
+	buf[0] = c;
+	buf[1] = NUL;
+    }
     screen_puts(buf, row, col, attr);
 }