From d11ba43bf08beffdf63c97feb7ef8577ccb4bb8c Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Sun, 20 Feb 2022 19:28:44 +0100
Subject: [PATCH] lmdb: Avoid getting packages with empty name, can lead to
 exception

---
 libpkg/data/storage.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libpkg/data/storage.cpp b/libpkg/data/storage.cpp
index 86ed0f1..57c9752 100644
--- a/libpkg/data/storage.cpp
+++ b/libpkg/data/storage.cpp
@@ -85,6 +85,10 @@ auto StorageCache<StorageEntriesType, StorageType, SpecType>::retrieve(Storage &
 template <typename StorageEntriesType, typename StorageType, typename SpecType>
 auto StorageCache<StorageEntriesType, StorageType, SpecType>::retrieve(Storage &storage, RWTxn *txn, const std::string &entryName) -> SpecType
 {
+    // do not attempt to fetch empty entries (apprently can lead to "Getting data: MDB_BAD_VALSIZE: Unsupported size of key/DB name/data, or wrong DUPFIXED size")
+    if (entryName.empty()) {
+        return SpecType(0, std::shared_ptr<Entry>());
+    }
     // check for package in cache
     using CacheRef = typename Entries::Ref;
     const auto ref = CacheRef(storage, entryName);