Allow the fuzzer to write empty buffer (i.e., len == 0) to the file
diff --git a/src/afl-fuzz-run.c b/src/afl-fuzz-run.c
index 2a1664e..f1da9c6 100644
--- a/src/afl-fuzz-run.c
+++ b/src/afl-fuzz-run.c
@@ -109,7 +109,7 @@
 
     });
 
-    if (unlikely(!new_buf && (new_size <= 0))) {
+    if (unlikely(!new_buf && (new_size < 0))) {
 
       FATAL("Custom_post_process failed (ret: %lu)", (long unsigned)new_size);