patch 7.4.870
Problem:    May get into an invalid state when using getchar() in an
            expression mapping.
Solution:   Anticipate mod_mask to change. (idea by Yukihiro Nakadaira)
diff --git a/src/version.c b/src/version.c
index bc1e555..0cb1fc6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    870,
+/**/
     869,
 /**/
     868,