patch 7.4.1688
Problem:    MzScheme does not support partial.
Solution:   Add minimal partial support. (Ken Takata)
diff --git a/src/version.c b/src/version.c
index 6e599d8..c7e1639 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1688,
+/**/
     1687,
 /**/
     1686,