From 9d95c228eeb2750d37f86228905d11eea5fb1e05 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Wed, 3 Jul 2024 16:28:24 +0200
Subject: [PATCH] Tarball fetcher: Fix fetchToStore() and eval caching

---
 src/libfetchers/fetchers.cc |  1 +
 src/libfetchers/tarball.cc  | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/src/libfetchers/fetchers.cc b/src/libfetchers/fetchers.cc
index 170a8910c..087880ebe 100644
--- a/src/libfetchers/fetchers.cc
+++ b/src/libfetchers/fetchers.cc
@@ -260,6 +260,7 @@ std::pair<ref<SourceAccessor>, Input> Input::getAccessorUnchecked(ref<Store> sto
 
     auto [accessor, final] = scheme->getAccessor(store, *this);
 
+    assert(!accessor->fingerprint);
     accessor->fingerprint = scheme->getFingerprint(store, final);
 
     return {accessor, std::move(final)};
diff --git a/src/libfetchers/tarball.cc b/src/libfetchers/tarball.cc
index 5de367052..aa8ff652f 100644
--- a/src/libfetchers/tarball.cc
+++ b/src/libfetchers/tarball.cc
@@ -365,6 +365,16 @@ struct TarballInputScheme : CurlInputScheme
 
         return {result.accessor, input};
     }
+
+    std::optional<std::string> getFingerprint(ref<Store> store, const Input & input) const override
+    {
+        if (auto narHash = input.getNarHash())
+            return narHash->to_string(HashFormat::SRI, true);
+        else if (auto rev = input.getRev())
+            return rev->gitRev();
+        else
+            return std::nullopt;
+    }
 };
 
 static auto rTarballInputScheme = OnStartup([] { registerInputScheme(std::make_unique<TarballInputScheme>()); });