From 7e630690fcb1107de89444f43aabcebce30b2933 Mon Sep 17 00:00:00 2001
From: ehgus607 <ehgus607@gmail.com>
Date: Sat, 27 Jun 2026 20:45:21 +0900
Subject: [PATCH] Fix UB on empty trampoline template entries

---
 src/e9patch/e9json.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/e9patch/e9json.cpp b/src/e9patch/e9json.cpp
index c3ed884..8736892 100644
--- a/src/e9patch/e9json.cpp
+++ b/src/e9patch/e9json.cpp
@@ -207,7 +207,8 @@ static Trampoline *dupTrampoline(const std::vector<Entry> &entries)
     T->prot        = PROT_READ | PROT_EXEC;
     T->preload     = false;
     T->num_entries = num_entries;
-    memcpy(T->entries, &entries[0], num_entries * sizeof(Entry));
+    if (num_entries > 0)
+        memcpy(T->entries, entries.data(), num_entries * sizeof(Entry));
 
     static std::set<Trampoline *, TrampolineCmp> cache;
     auto i = cache.insert(T);