This patch fixes the issue.
Index: mailavenger-0.8.4/libasync/maketables.c
===================================================================
--- mailavenger-0.8.4.orig/libasync/maketables.c
+++ mailavenger-0.8.4/libasync/maketables.c
@@ -132,7 +132,9 @@ for (i = 0; i < 256; i++)
meta-character, which in this sense is any character that terminates a run
of data characters. */
- if (strchr("*+?{^.$|()[", i) != 0) x += ctype_meta; *p++ = x; }
+ if (strchr("*+?{^.$|()[", i) != 0) x += ctype_meta;
+ *p++ = x;
+ }
return yield;
}