Author: Lars Mueller <lmuelle@suse.com>
Date:   Wed Jul 23 07:22:52 2014 -0700

    Bug 1506: Silence static checkers.
····
    Re-adds a return NULL which was removed because it was redundant. Static
      checkers don't parse the logic, so adding it back to make them happy.

Index: exim-4.83/src/expand.c
===================================================================
--- exim-4.83.orig/src/expand.c
+++ exim-4.83/src/expand.c
@@ -1879,6 +1879,8 @@ switch (vp->type)
   #endif
 
   }
+
+return NULL;  /* Unknown variable. Silences static checkers. */
 }