Merge pull request #3899 from obsidiansystems/make-narHash-not-optional

Make narHash in ValidPathInfo not optional

13 files changed, 101 insertions, 88 deletions

diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index c360b9dda..5433fe50d 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -143,7 +143,7 @@ struct FileSource : FdSource
 void BinaryCacheStore::addToStore(const ValidPathInfo & info, Source & narSource,
     RepairFlag repair, CheckSigsFlag checkSigs)
 {
-    assert(info.narHash && info.narSize);
+    assert(info.narSize);
 
     if (!repair && isValidPath(info.path)) {
         // FIXME: copyNAR -> null sink
@@ -381,7 +381,10 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
         h = hashString(hashAlgo, s);
     }
 
-    ValidPathInfo info(makeFixedOutputPath(method, *h, name));
+    ValidPathInfo info {
+        makeFixedOutputPath(method, *h, name),
+        Hash::dummy, // Will be fixed in addToStore, which recomputes nar hash
+    };
 
     auto source = StringSource { *sink.s };
     addToStore(info, source, repair, CheckSigs);
@@ -392,7 +395,10 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
 StorePath BinaryCacheStore::addTextToStore(const string & name, const string & s,
     const StorePathSet & references, RepairFlag repair)
 {
-    ValidPathInfo info(computeStorePathForText(name, s, references));
+    ValidPathInfo info {
+        computeStorePathForText(name, s, references),
+        Hash::dummy, // Will be fixed in addToStore, which recomputes nar hash
+    };
     info.references = references;
 
     if (repair || !isValidPath(info.path)) {
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 3fb052f00..aa0009e7f 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -3865,8 +3865,10 @@ void DerivationGoal::registerOutputs()
             worker.markContentsGood(worker.store.parseStorePath(path));
         }
 
-        ValidPathInfo info(worker.store.parseStorePath(path));
-        info.narHash = hash.first;
+        ValidPathInfo info {
+            worker.store.parseStorePath(path),
+            hash.first,
+        };
         info.narSize = hash.second;
         info.references = std::move(references);
         info.deriver = drvPath;
@@ -5071,7 +5073,7 @@ bool Worker::pathContentsGood(const StorePath & path)
     if (!pathExists(store.printStorePath(path)))
         res = false;
     else {
-        HashResult current = hashPath(info->narHash->type, store.printStorePath(path));
+        HashResult current = hashPath(info->narHash.type, store.printStorePath(path));
         Hash nullHash(htSHA256);
         res = info->narHash == nullHash || info->narHash == current.first;
     }
diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index 7a6eb99be..07278d383 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -289,7 +289,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         auto hash = store->queryPathInfo(path)->narHash;
         logger->stopWork();
-        to << hash->to_string(Base16, false);
+        to << hash.to_string(Base16, false);
         break;
     }
 
@@ -638,7 +638,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
             if (GET_PROTOCOL_MINOR(clientVersion) >= 17)
                 to << 1;
             to << (info->deriver ? store->printStorePath(*info->deriver) : "")
-               << info->narHash->to_string(Base16, false);
+               << info->narHash.to_string(Base16, false);
             writeStorePaths(*store, to, info->references);
             to << info->registrationTime << info->narSize;
             if (GET_PROTOCOL_MINOR(clientVersion) >= 16) {
@@ -694,11 +694,12 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
 
     case wopAddToStoreNar: {
         bool repair, dontCheckSigs;
-        ValidPathInfo info(store->parseStorePath(readString(from)));
+        auto path = store->parseStorePath(readString(from));
         auto deriver = readString(from);
+        auto narHash = Hash::parseAny(readString(from), htSHA256);
+        ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = store->parseStorePath(deriver);
-        info.narHash = Hash::parseAny(readString(from), htSHA256);
         info.references = readStorePaths<StorePathSet>(*store, from);
         from >> info.registrationTime >> info.narSize >> info.ultimate;
         info.sigs = readStrings<StringSet>(from);
diff --git a/src/libstore/export-import.cc b/src/libstore/export-import.cc
index a0fc22264..ccd466d09 100644
--- a/src/libstore/export-import.cc
+++ b/src/libstore/export-import.cc
@@ -38,9 +38,9 @@ void Store::exportPath(const StorePath & path, Sink & sink)
        filesystem corruption from spreading to other machines.
        Don't complain if the stored hash is zero (unknown). */
     Hash hash = hashSink.currentHash().first;
-    if (hash != info->narHash && info->narHash != Hash(info->narHash->type))
+    if (hash != info->narHash && info->narHash != Hash(info->narHash.type))
         throw Error("hash of path '%s' has changed from '%s' to '%s'!",
-            printStorePath(path), info->narHash->to_string(Base32, true), hash.to_string(Base32, true));
+            printStorePath(path), info->narHash.to_string(Base32, true), hash.to_string(Base32, true));
 
     teeSink
         << exportMagic
@@ -69,17 +69,18 @@ StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
         if (magic != exportMagic)
             throw Error("Nix archive cannot be imported; wrong format");
 
-        ValidPathInfo info(parseStorePath(readString(source)));
+        auto path = parseStorePath(readString(source));
 
         //Activity act(*logger, lvlInfo, format("importing path '%s'") % info.path);
 
-        info.references = readStorePaths<StorePathSet>(*this, source);
-
+        auto references = readStorePaths<StorePathSet>(*this, source);
         auto deriver = readString(source);
+        auto narHash = hashString(htSHA256, *saved.s);
+
+        ValidPathInfo info { path, narHash };
         if (deriver != "")
             info.deriver = parseStorePath(deriver);
-
-        info.narHash = hashString(htSHA256, *saved.s);
+        info.references = references;
         info.narSize = saved.s->size();
 
         // Ignore optional legacy signature.
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index c6eeab548..9f95a9726 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -93,6 +93,9 @@ struct LegacySSHStore : public Store
         try {
             auto conn(connections->get());
 
+            /* No longer support missing NAR hash */
+            assert(GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4);
+
             debug("querying remote host '%s' for info on '%s'", host, printStorePath(path));
 
             conn->to << cmdQueryPathInfos << PathSet{printStorePath(path)};
@@ -100,8 +103,10 @@ struct LegacySSHStore : public Store
 
             auto p = readString(conn->from);
             if (p.empty()) return callback(nullptr);
-            auto info = std::make_shared<ValidPathInfo>(parseStorePath(p));
-            assert(path == info->path);
+            auto path2 = parseStorePath(p);
+            assert(path == path2);
+            /* Hash will be set below. FIXME construct ValidPathInfo at end. */
+            auto info = std::make_shared<ValidPathInfo>(path, Hash::dummy);
 
             PathSet references;
             auto deriver = readString(conn->from);
@@ -111,12 +116,14 @@ struct LegacySSHStore : public Store
             readLongLong(conn->from); // download size
             info->narSize = readLongLong(conn->from);
 
-            if (GET_PROTOCOL_MINOR(conn->remoteVersion) >= 4) {
+            {
                 auto s = readString(conn->from);
-                info->narHash = s.empty() ? std::optional<Hash>{} : Hash::parseAnyPrefixed(s);
-                info->ca = parseContentAddressOpt(readString(conn->from));
-                info->sigs = readStrings<StringSet>(conn->from);
+                if (s == "")
+                    throw Error("NAR hash is now mandatory");
+                info->narHash = Hash::parseAnyPrefixed(s);
             }
+            info->ca = parseContentAddressOpt(readString(conn->from));
+            info->sigs = readStrings<StringSet>(conn->from);
 
             auto s = readString(conn->from);
             assert(s == "");
@@ -138,7 +145,7 @@ struct LegacySSHStore : public Store
                 << cmdAddToStoreNar
                 << printStorePath(info.path)
                 << (info.deriver ? printStorePath(*info.deriver) : "")
-                << info.narHash->to_string(Base16, false);
+                << info.narHash.to_string(Base16, false);
             writeStorePaths(*this, conn->to, info.references);
             conn->to
                 << info.registrationTime
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index e552bdc59..8cb1af7c7 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -594,7 +594,7 @@ uint64_t LocalStore::addValidPath(State & state,
 
     state.stmtRegisterValidPath.use()
         (printStorePath(info.path))
-        (info.narHash->to_string(Base16, true))
+        (info.narHash.to_string(Base16, true))
         (info.registrationTime == 0 ? time(0) : info.registrationTime)
         (info.deriver ? printStorePath(*info.deriver) : "", (bool) info.deriver)
         (info.narSize, info.narSize != 0)
@@ -641,25 +641,28 @@ void LocalStore::queryPathInfoUncached(const StorePath & path,
     Callback<std::shared_ptr<const ValidPathInfo>> callback) noexcept
 {
     try {
-        auto info = std::make_shared<ValidPathInfo>(path);
-
         callback(retrySQLite<std::shared_ptr<ValidPathInfo>>([&]() {
             auto state(_state.lock());
 
             /* Get the path info. */
-            auto useQueryPathInfo(state->stmtQueryPathInfo.use()(printStorePath(info->path)));
+            auto useQueryPathInfo(state->stmtQueryPathInfo.use()(printStorePath(path)));
 
             if (!useQueryPathInfo.next())
                 return std::shared_ptr<ValidPathInfo>();
 
-            info->id = useQueryPathInfo.getInt(0);
+            auto id = useQueryPathInfo.getInt(0);
 
+            auto narHash = Hash::dummy;
             try {
-                info->narHash = Hash::parseAnyPrefixed(useQueryPathInfo.getStr(1));
+                narHash = Hash::parseAnyPrefixed(useQueryPathInfo.getStr(1));
             } catch (BadHash & e) {
-                throw Error("in valid-path entry for '%s': %s", printStorePath(path), e.what());
+                throw Error("invalid-path entry for '%s': %s", printStorePath(path), e.what());
             }
 
+            auto info = std::make_shared<ValidPathInfo>(path, narHash);
+
+            info->id = id;
+
             info->registrationTime = useQueryPathInfo.getInt(2);
 
             auto s = (const char *) sqlite3_column_text(state->stmtQueryPathInfo, 3);
@@ -694,7 +697,7 @@ void LocalStore::updatePathInfo(State & state, const ValidPathInfo & info)
 {
     state.stmtUpdatePathInfo.use()
         (info.narSize, info.narSize != 0)
-        (info.narHash->to_string(Base16, true))
+        (info.narHash.to_string(Base16, true))
         (info.ultimate ? 1 : 0, info.ultimate)
         (concatStringsSep(" ", info.sigs), !info.sigs.empty())
         (renderContentAddress(info.ca), (bool) info.ca)
@@ -920,7 +923,7 @@ void LocalStore::registerValidPaths(const ValidPathInfos & infos)
         StorePathSet paths;
 
         for (auto & i : infos) {
-            assert(i.narHash && i.narHash->type == htSHA256);
+            assert(i.narHash.type == htSHA256);
             if (isValidPath_(*state, i.path))
                 updatePathInfo(*state, i);
             else
@@ -984,9 +987,6 @@ const PublicKeys & LocalStore::getPublicKeys()
 void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
     RepairFlag repair, CheckSigsFlag checkSigs)
 {
-    if (!info.narHash)
-        throw Error("cannot add path '%s' because it lacks a hash", printStorePath(info.path));
-
     if (requireSigs && checkSigs && !info.checkSignatures(*this, getPublicKeys()))
         throw Error("cannot add path '%s' because it lacks a valid signature", printStorePath(info.path));
 
@@ -1029,7 +1029,7 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
 
             if (hashResult.first != info.narHash)
                 throw Error("hash mismatch importing path '%s';\n  wanted: %s\n  got:    %s",
-                    printStorePath(info.path), info.narHash->to_string(Base32, true), hashResult.first.to_string(Base32, true));
+                    printStorePath(info.path), info.narHash.to_string(Base32, true), hashResult.first.to_string(Base32, true));
 
             if (hashResult.second != info.narSize)
                 throw Error("size mismatch importing path '%s';\n  wanted: %s\n  got:   %s",
@@ -1151,8 +1151,7 @@ StorePath LocalStore::addToStoreFromDump(Source & source0, const string & name,
 
             optimisePath(realPath);
 
-            ValidPathInfo info(dstPath);
-            info.narHash = narHash.first;
+            ValidPathInfo info { dstPath, narHash.first };
             info.narSize = narHash.second;
             info.ca = FixedOutputHash { .method = method, .hash = hash };
             registerValidPath(info);
@@ -1195,8 +1194,7 @@ StorePath LocalStore::addTextToStore(const string & name, const string & s,
 
             optimisePath(realPath);
 
-            ValidPathInfo info(dstPath);
-            info.narHash = narHash;
+            ValidPathInfo info { dstPath, narHash };
             info.narSize = sink.s->size();
             info.references = references;
             info.ca = TextHash { .hash = hash };
@@ -1311,9 +1309,9 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
 
                 std::unique_ptr<AbstractHashSink> hashSink;
                 if (!info->ca || !info->references.count(info->path))
-                    hashSink = std::make_unique<HashSink>(info->narHash->type);
+                    hashSink = std::make_unique<HashSink>(info->narHash.type);
                 else
-                    hashSink = std::make_unique<HashModuloSink>(info->narHash->type, std::string(info->path.hashPart()));
+                    hashSink = std::make_unique<HashModuloSink>(info->narHash.type, std::string(info->path.hashPart()));
 
                 dumpPath(Store::toRealPath(i), *hashSink);
                 auto current = hashSink->finish();
@@ -1322,7 +1320,7 @@ bool LocalStore::verifyStore(bool checkContents, RepairFlag repair)
                     logError({
                         .name = "Invalid hash - path modified",
                         .hint = hintfmt("path '%s' was modified! expected hash '%s', got '%s'",
-                        printStorePath(i), info->narHash->to_string(Base32, true), current.first.to_string(Base32, true))
+                        printStorePath(i), info->narHash.to_string(Base32, true), current.first.to_string(Base32, true))
                     });
                     if (repair) repairPath(i); else errors = true;
                 } else {
diff --git a/src/libstore/nar-info-disk-cache.cc b/src/libstore/nar-info-disk-cache.cc
index 92da14e23..8541cc51f 100644
--- a/src/libstore/nar-info-disk-cache.cc
+++ b/src/libstore/nar-info-disk-cache.cc
@@ -189,13 +189,14 @@ public:
                 return {oInvalid, 0};
 
             auto namePart = queryNAR.getStr(1);
-            auto narInfo = make_ref<NarInfo>(StorePath(hashPart + "-" + namePart));
+            auto narInfo = make_ref<NarInfo>(
+                StorePath(hashPart + "-" + namePart),
+                Hash::parseAnyPrefixed(queryNAR.getStr(6)));
             narInfo->url = queryNAR.getStr(2);
             narInfo->compression = queryNAR.getStr(3);
             if (!queryNAR.isNull(4))
                 narInfo->fileHash = Hash::parseAnyPrefixed(queryNAR.getStr(4));
             narInfo->fileSize = queryNAR.getInt(5);
-            narInfo->narHash = Hash::parseAnyPrefixed(queryNAR.getStr(6));
             narInfo->narSize = queryNAR.getInt(7);
             for (auto & r : tokenizeString<Strings>(queryNAR.getStr(8), " "))
                 narInfo->references.insert(StorePath(r));
@@ -232,7 +233,7 @@ public:
                     (narInfo ? narInfo->compression : "", narInfo != 0)
                     (narInfo && narInfo->fileHash ? narInfo->fileHash->to_string(Base32, true) : "", narInfo && narInfo->fileHash)
                     (narInfo ? narInfo->fileSize : 0, narInfo != 0 && narInfo->fileSize)
-                    (info->narHash->to_string(Base32, true))
+                    (info->narHash.to_string(Base32, true))
                     (info->narSize)
                     (concatStringsSep(" ", info->shortRefs()))
                     (info->deriver ? std::string(info->deriver->to_string()) : "", (bool) info->deriver)
diff --git a/src/libstore/nar-info.cc b/src/libstore/nar-info.cc
index 5812aa4ac..3454f34bb 100644
--- a/src/libstore/nar-info.cc
+++ b/src/libstore/nar-info.cc
@@ -1,10 +1,11 @@
 #include "globals.hh"
 #include "nar-info.hh"
+#include "store-api.hh"
 
 namespace nix {
 
 NarInfo::NarInfo(const Store & store, const std::string & s, const std::string & whence)
-    : ValidPathInfo(StorePath(StorePath::dummy)) // FIXME: hack
+    : ValidPathInfo(StorePath(StorePath::dummy), Hash(Hash::dummy)) // FIXME: hack
 {
     auto corrupt = [&]() {
         return Error("NAR info file '%1%' is corrupt", whence);
@@ -19,6 +20,7 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
     };
 
     bool havePath = false;
+    bool haveNarHash = false;
 
     size_t pos = 0;
     while (pos < s.size()) {
@@ -46,8 +48,10 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
         else if (name == "FileSize") {
             if (!string2Int(value, fileSize)) throw corrupt();
         }
-        else if (name == "NarHash")
+        else if (name == "NarHash") {
             narHash = parseHashField(value);
+            haveNarHash = true;
+        }
         else if (name == "NarSize") {
             if (!string2Int(value, narSize)) throw corrupt();
         }
@@ -76,7 +80,7 @@ NarInfo::NarInfo(const Store & store, const std::string & s, const std::string &
 
     if (compression == "") compression = "bzip2";
 
-    if (!havePath || url.empty() || narSize == 0 || !narHash) throw corrupt();
+    if (!havePath || !haveNarHash || url.empty() || narSize == 0) throw corrupt();
 }
 
 std::string NarInfo::to_string(const Store & store) const
@@ -89,8 +93,8 @@ std::string NarInfo::to_string(const Store & store) const
     assert(fileHash && fileHash->type == htSHA256);
     res += "FileHash: " + fileHash->to_string(Base32, true) + "\n";
     res += "FileSize: " + std::to_string(fileSize) + "\n";
-    assert(narHash && narHash->type == htSHA256);
-    res += "NarHash: " + narHash->to_string(Base32, true) + "\n";
+    assert(narHash.type == htSHA256);
+    res += "NarHash: " + narHash.to_string(Base32, true) + "\n";
     res += "NarSize: " + std::to_string(narSize) + "\n";
 
     res += "References: " + concatStringsSep(" ", shortRefs()) + "\n";
diff --git a/src/libstore/nar-info.hh b/src/libstore/nar-info.hh
index eff19f0ef..39ced76e5 100644
--- a/src/libstore/nar-info.hh
+++ b/src/libstore/nar-info.hh
@@ -2,10 +2,12 @@
 
 #include "types.hh"
 #include "hash.hh"
-#include "store-api.hh"
+#include "path-info.hh"
 
 namespace nix {
 
+class Store;
+
 struct NarInfo : ValidPathInfo
 {
     std::string url;
@@ -15,7 +17,7 @@ struct NarInfo : ValidPathInfo
     std::string system;
 
     NarInfo() = delete;
-    NarInfo(StorePath && path) : ValidPathInfo(std::move(path)) { }
+    NarInfo(StorePath && path, Hash narHash) : ValidPathInfo(std::move(path), narHash) { }
     NarInfo(const ValidPathInfo & info) : ValidPathInfo(info) { }
     NarInfo(const Store & store, const std::string & s, const std::string & whence);
 
diff --git a/src/libstore/path-info.hh b/src/libstore/path-info.hh
index 2a015ea3c..8ff5c466e 100644
--- a/src/libstore/path-info.hh
+++ b/src/libstore/path-info.hh
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "crypto.hh"
 #include "path.hh"
 #include "hash.hh"
 #include "content-address.hh"
@@ -29,7 +30,7 @@ struct ValidPathInfo
     StorePath path;
     std::optional<StorePath> deriver;
     // TODO document this
-    std::optional<Hash> narHash;
+    Hash narHash;
     StorePathSet references;
     time_t registrationTime = 0;
     uint64_t narSize = 0; // 0 = unknown
@@ -100,8 +101,8 @@ struct ValidPathInfo
 
     ValidPathInfo(const ValidPathInfo & other) = default;
 
-    ValidPathInfo(StorePath && path) : path(std::move(path)) { };
-    ValidPathInfo(const StorePath & path) : path(path) { };
+    ValidPathInfo(StorePath && path, Hash narHash) : path(std::move(path)), narHash(narHash) { };
+    ValidPathInfo(const StorePath & path, Hash narHash) : path(path), narHash(narHash) { };
 
     virtual ~ValidPathInfo() { }
 };
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 33d1e431b..8dcc1d710 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -419,10 +419,10 @@ void RemoteStore::queryPathInfoUncached(const StorePath & path,
                 bool valid; conn->from >> valid;
                 if (!valid) throw InvalidPath("path '%s' is not valid", printStorePath(path));
             }
-            info = std::make_shared<ValidPathInfo>(StorePath(path));
             auto deriver = readString(conn->from);
+            auto narHash = Hash::parseAny(readString(conn->from), htSHA256);
+            info = std::make_shared<ValidPathInfo>(path, narHash);
             if (deriver != "") info->deriver = parseStorePath(deriver);
-            info->narHash = Hash::parseAny(readString(conn->from), htSHA256);
             info->references = readStorePaths<StorePathSet>(*this, conn->from);
             conn->from >> info->registrationTime >> info->narSize;
             if (GET_PROTOCOL_MINOR(conn->daemonVersion) >= 16) {
@@ -521,7 +521,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
         conn->to << wopAddToStoreNar
                  << printStorePath(info.path)
                  << (info.deriver ? printStorePath(*info.deriver) : "")
-                 << info.narHash->to_string(Base16, false);
+                 << info.narHash.to_string(Base16, false);
         writeStorePaths(*this, conn->to, info.references);
         conn->to << info.registrationTime << info.narSize
                  << info.ultimate << info.sigs << renderContentAddress(info.ca)
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 3d07e2d38..539a66c98 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -320,8 +320,10 @@ ValidPathInfo Store::addToStoreSlow(std::string_view name, const Path & srcPath,
     if (expectedCAHash && expectedCAHash != hash)
         throw Error("hash mismatch for '%s'", srcPath);
 
-    ValidPathInfo info(makeFixedOutputPath(method, hash, name));
-    info.narHash = narHash;
+    ValidPathInfo info {
+        makeFixedOutputPath(method, hash, name),
+        narHash,
+    };
     info.narSize = narSize;
     info.ca = FixedOutputHash { .method = method, .hash = hash };
 
@@ -565,7 +567,7 @@ string Store::makeValidityRegistration(const StorePathSet & paths,
         auto info = queryPathInfo(i);
 
         if (showHash) {
-            s += info->narHash->to_string(Base16, false) + "\n";
+            s += info->narHash.to_string(Base16, false) + "\n";
             s += (format("%1%\n") % info->narSize).str();
         }
 
@@ -597,7 +599,7 @@ void Store::pathInfoToJSON(JSONPlaceholder & jsonOut, const StorePathSet & store
             auto info = queryPathInfo(storePath);
 
             jsonPath
-                .attr("narHash", info->narHash->to_string(hashBase, true))
+                .attr("narHash", info->narHash.to_string(hashBase, true))
                 .attr("narSize", info->narSize);
 
             {
@@ -725,20 +727,6 @@ void copyStorePath(ref<Store> srcStore, ref<Store> dstStore,
         info = info2;
     }
 
-    if (!info->narHash) {
-        StringSink sink;
-        srcStore->narFromPath({storePath}, sink);
-        auto info2 = make_ref<ValidPathInfo>(*info);
-        info2->narHash = hashString(htSHA256, *sink.s);
-        if (!info->narSize) info2->narSize = sink.s->size();
-        if (info->ultimate) info2->ultimate = false;
-        info = info2;
-
-        StringSource source(*sink.s);
-        dstStore->addToStore(*info, source, repair, checkSigs);
-        return;
-    }
-
     if (info->ultimate) {
         auto info2 = make_ref<ValidPathInfo>(*info);
         info2->ultimate = false;
@@ -863,19 +851,22 @@ void copyClosure(ref<Store> srcStore, ref<Store> dstStore,
 }
 
 
-std::optional<ValidPathInfo> decodeValidPathInfo(const Store & store, std::istream & str, bool hashGiven)
+std::optional<ValidPathInfo> decodeValidPathInfo(const Store & store, std::istream & str, std::optional<HashResult> hashGiven)
 {
     std::string path;
     getline(str, path);
     if (str.eof()) { return {}; }
-    ValidPathInfo info(store.parseStorePath(path));
-    if (hashGiven) {
+    if (!hashGiven) {
         string s;
         getline(str, s);
-        info.narHash = Hash::parseAny(s, htSHA256);
+        auto narHash = Hash::parseAny(s, htSHA256);
         getline(str, s);
-        if (!string2Int(s, info.narSize)) throw Error("number expected");
+        uint64_t narSize;
+        if (!string2Int(s, narSize)) throw Error("number expected");
+        hashGiven = { narHash, narSize };
     }
+    ValidPathInfo info(store.parseStorePath(path), hashGiven->first);
+    info.narSize = hashGiven->second;
     std::string deriver;
     getline(str, deriver);
     if (deriver != "") info.deriver = store.parseStorePath(deriver);
@@ -910,12 +901,12 @@ string showPaths(const PathSet & paths)
 
 std::string ValidPathInfo::fingerprint(const Store & store) const
 {
-    if (narSize == 0 || !narHash)
-        throw Error("cannot calculate fingerprint of path '%s' because its size/hash is not known",
+    if (narSize == 0)
+        throw Error("cannot calculate fingerprint of path '%s' because its size is not known",
             store.printStorePath(path));
     return
         "1;" + store.printStorePath(path) + ";"
-        + narHash->to_string(Base32, true) + ";"
+        + narHash.to_string(Base32, true) + ";"
         + std::to_string(narSize) + ";"
         + concatStringsSep(",", store.printStorePathSet(references));
 }
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index e94d975c5..f6f6acaf5 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -4,7 +4,6 @@
 #include "hash.hh"
 #include "content-address.hh"
 #include "serialise.hh"
-#include "crypto.hh"
 #include "lru-cache.hh"
 #include "sync.hh"
 #include "globals.hh"
@@ -761,7 +760,7 @@ string showPaths(const PathSet & paths);
 std::optional<ValidPathInfo> decodeValidPathInfo(
     const Store & store,
     std::istream & str,
-    bool hashGiven = false);
+    std::optional<HashResult> hashGiven = std::nullopt);
 
 /* Split URI into protocol+hierarchy part and its parameter set. */
 std::pair<std::string, Store::Params> splitUriAndParams(const std::string & uri);