diff --git a/patchlevel.h b/patchlevel.h
--- a/patchlevel.h
+++ b/patchlevel.h
@@ -25,6 +25,6 @@
    regexp `^#define[ 	]*PATCHLEVEL', since that's what support/mkversion.sh
    looks for to find the patch level (for the sccs version string). */
 
-#define PATCHLEVEL 4
+#define PATCHLEVEL 5
 
 #endif /* _PATCHLEVEL_H_ */
diff --git a/subst.c b/subst.c
--- a/subst.c
+++ b/subst.c
@@ -8965,7 +8965,8 @@ pat_subst (string, pat, rep, mflags)
       return (ret);
     }
   else if (*string == 0 && (match_pattern (string, pat, mtype, &s, &e) != 0))
-    return ((mflags & MATCH_EXPREP) ? strcreplace (rep, '&', "", 2) : savestring (rep));
+    return (mflags & MATCH_EXPREP) ? strcreplace (rep, '&', "", 2)
+				   : (rep ? savestring (rep) : savestring (""));
 
   ret = (char *)xmalloc (rsize = 64);
   ret[0] = '\0';