From 3b6cd3bc45a214221ac1dc524acd51ff28e6938f Mon Sep 17 00:00:00 2001
From: Alwin Berger <alwin.berger@tu-dortmund.de>
Date: Thu, 15 Aug 2024 09:38:52 +0200
Subject: [PATCH] fix bug causing skipped mutation when part size is 0

---
 libafl/src/mutators/multi.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libafl/src/mutators/multi.rs b/libafl/src/mutators/multi.rs
index 591dd50eb7..c74daf1712 100644
--- a/libafl/src/mutators/multi.rs
+++ b/libafl/src/mutators/multi.rs
@@ -299,6 +299,10 @@ where
             drop(other_testcase);
             let size = part.bytes().len();
 
+            if size == 0 {  // Workaround for a bug where parts are empty. The origin remains unknown.
+                return Ok(MutationResult::Skipped);
+            }
+
             let target = state.rand_mut().below(size);
             let range = rand_range(state, other_size, min(other_size, size - target));