From 42ba65e864bb5531c5fc22745994465ba1a35da7 Mon Sep 17 00:00:00 2001
From: Valentin Huber <git@valentinhuber.me>
Date: Fri, 6 Dec 2024 18:32:58 +0100
Subject: [PATCH] Fix empty multipart name (#2750)

---
 libafl/src/inputs/multi.rs | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/libafl/src/inputs/multi.rs b/libafl/src/inputs/multi.rs
index 7ebdd0f2c5..55353faa4c 100644
--- a/libafl/src/inputs/multi.rs
+++ b/libafl/src/inputs/multi.rs
@@ -154,12 +154,16 @@ where
     I: Input,
 {
     fn generate_name(&self, id: Option<CorpusId>) -> String {
-        self.names
-            .iter()
-            .cloned()
-            .zip(self.parts.iter().map(|i| i.generate_name(id)))
-            .map(|(name, generated)| format!("{name}-{generated}"))
-            .collect::<Vec<_>>()
-            .join(",")
+        if self.names().len() > 0 {
+            self.names
+                .iter()
+                .cloned()
+                .zip(self.parts.iter().map(|i| i.generate_name(id)))
+                .map(|(name, generated)| format!("{name}-{generated}"))
+                .collect::<Vec<_>>()
+                .join(",")
+        } else {
+            "empty_multipart".to_string() // empty strings cause issues with OnDiskCorpus
+        }
     }
 }