Remove superfluous TreeInfo::rev field

src/libexpr/flake/flake.cc

@@ -567,17 +567,21 @@ LockedFlake lockFlake(
     return LockedFlake { .flake = std::move(flake), .lockFile = std::move(newLockFile) };
 }
 
-static void emitSourceInfoAttrs(EvalState & state, const fetchers::Tree & sourceInfo, Value & vAttrs)
+static void emitSourceInfoAttrs(
+    EvalState & state,
+    const FlakeRef & flakeRef,
+    const fetchers::Tree & sourceInfo,
+    Value & vAttrs)
 {
     assert(state.store->isValidPath(sourceInfo.storePath));
     auto pathS = state.store->printStorePath(sourceInfo.storePath);
     mkString(*state.allocAttr(vAttrs, state.sOutPath), pathS, {pathS});
 
-    if (sourceInfo.info.rev) {
+    if (auto rev = flakeRef.input->getRev()) {
         mkString(*state.allocAttr(vAttrs, state.symbols.create("rev")),
-            sourceInfo.info.rev->gitRev());
+            rev->gitRev());
         mkString(*state.allocAttr(vAttrs, state.symbols.create("shortRev")),
-            sourceInfo.info.rev->gitShortRev());
+            rev->gitShortRev());
     }
 
     if (sourceInfo.info.revCount)
@@ -639,7 +643,7 @@ static void prim_callFlake(EvalState & state, const Pos & pos, Value * * args, V
 
         mkString(*state.allocAttr(v, state.sOutPath), pathS, {pathS});
 
-        emitSourceInfoAttrs(state, sourceInfo, v);
+        emitSourceInfoAttrs(state, resolvedRef, sourceInfo, v);
 
         v.attrs->sort();
     }
@@ -672,7 +676,7 @@ void callFlake(EvalState & state,
 
     auto & vSourceInfo = *state.allocValue();
     state.mkAttrs(vSourceInfo, 8);
-    emitSourceInfoAttrs(state, *flake.sourceInfo, vSourceInfo);
+    emitSourceInfoAttrs(state, flake.resolvedRef, *flake.sourceInfo, vSourceInfo);
     vSourceInfo.attrs->sort();
 
     vInputs.attrs->push_back(Attr(state.sSelf, &vRes));

src/libexpr/flake/lockfile.cc

@@ -58,10 +58,6 @@ static TreeInfo parseTreeInfo(const nlohmann::json & json)
         else
             throw Error("attribute 'narHash' missing in lock file");
 
-        j = i2.find("rev");
-        if (j != i2.end())
-            info.rev = Hash((std::string) *j, htSHA1);
-
         j = i2.find("revCount");
         if (j != i2.end())
             info.revCount = *j;
@@ -97,8 +93,6 @@ static nlohmann::json treeInfoToJson(const TreeInfo & info)
     nlohmann::json json;
     assert(info.narHash);
     json["narHash"] = info.narHash.to_string(SRI);
-    if (info.rev)
-        json["rev"] = info.rev->gitRev();
     if (info.revCount)
         json["revCount"] = *info.revCount;
     if (info.lastModified)

src/libexpr/primops/fetchGit.cc

@@ -57,14 +57,14 @@ static void prim_fetchGit(EvalState & state, const Pos & pos, Value * * args, Va
     // FIXME: use name
     auto input = inputFromURL(parsedUrl);
 
-    auto tree = input->fetchTree(state.store).first;
+    auto [tree, input2] = input->fetchTree(state.store);
 
     state.mkAttrs(v, 8);
     auto storePath = state.store->printStorePath(tree.storePath);
     mkString(*state.allocAttr(v, state.sOutPath), storePath, PathSet({storePath}));
     // Backward compatibility: set 'rev' to
     // 0000000000000000000000000000000000000000 for a dirty tree.
-    auto rev2 = tree.info.rev.value_or(Hash(htSHA1));
+    auto rev2 = input2->getRev().value_or(Hash(htSHA1));
     mkString(*state.allocAttr(v, state.symbols.create("rev")), rev2.gitRev());
     mkString(*state.allocAttr(v, state.symbols.create("shortRev")), rev2.gitShortRev());
     assert(tree.info.revCount);

src/libexpr/primops/fetchMercurial.cc

@@ -73,7 +73,7 @@ static void prim_fetchMercurial(EvalState & state, const Pos & pos, Value * * ar
         mkString(*state.allocAttr(v, state.symbols.create("branch")), *input2->getRef());
     // Backward compatibility: set 'rev' to
     // 0000000000000000000000000000000000000000 for a dirty tree.
-    auto rev2 = tree.info.rev.value_or(Hash(htSHA1));
+    auto rev2 = input2->getRev().value_or(Hash(htSHA1));
     mkString(*state.allocAttr(v, state.symbols.create("rev")), rev2.gitRev());
     mkString(*state.allocAttr(v, state.symbols.create("shortRev")), std::string(rev2.gitRev(), 0, 12));
     if (tree.info.revCount)

src/libstore/fetchers/git.cc

@@ -23,21 +23,25 @@ static Path getCacheInfoPathFor(const std::string & name, const Hash & rev)
     return cacheDir + "/" + linkName + ".link";
 }
 
-static void cacheGitInfo(Store & store, const std::string & name, const Tree & tree)
+static void cacheGitInfo(
+    Store & store,
+    const std::string & name,
+    const Tree & tree,
+    const Hash & rev)
 {
     nlohmann::json json;
     json["storePath"] = store.printStorePath(tree.storePath);
     json["name"] = name;
-    json["rev"] = tree.info.rev->gitRev();
+    json["rev"] = rev.gitRev();
     json["revCount"] = *tree.info.revCount;
     json["lastModified"] = *tree.info.lastModified;
 
-    auto cacheInfoPath = getCacheInfoPathFor(name, *tree.info.rev);
+    auto cacheInfoPath = getCacheInfoPathFor(name, rev);
     createDirs(dirOf(cacheInfoPath));
     writeFile(cacheInfoPath, json.dump());
 }
 
-static std::optional<Tree> lookupGitInfo(
+static std::optional<std::pair<Hash, Tree>> lookupGitInfo(
     ref<Store> store,
     const std::string & name,
     const Hash & rev)
@@ -50,16 +54,14 @@ static std::optional<Tree> lookupGitInfo(
         auto storePath = store->parseStorePath((std::string) json["storePath"]);
 
         if (store->isValidPath(storePath)) {
-            Tree tree{
+            return {{rev, Tree{
                 .actualPath = store->toRealPath(store->printStorePath(storePath)),
                 .storePath = std::move(storePath),
                 .info = TreeInfo {
-                    .rev = rev,
                     .revCount = json["revCount"],
                     .lastModified = json["lastModified"],
                 }
-            };
+            }}};
-            return tree;
         }
 
     } catch (SysError & e) {
@@ -181,8 +183,10 @@ struct GitInput : Input
         assert(!rev || rev->type == htSHA1);
 
         if (rev) {
-            if (auto tree = lookupGitInfo(store, name, *rev))
+            if (auto tree = lookupGitInfo(store, name, *rev)) {
-                return {std::move(*tree), input};
+                input->rev = tree->first;
+                return {std::move(tree->second), input};
+            }
         }
 
         auto [isLocal, actualUrl_] = getActualUrl();
@@ -326,8 +330,10 @@ struct GitInput : Input
                 input->rev = Hash(chomp(readFile(localRefFile)), htSHA1);
         }
 
-        if (auto tree = lookupGitInfo(store, name, *input->rev))
+        if (auto tree = lookupGitInfo(store, name, *input->rev)) {
-            return {std::move(*tree), input};
+            assert(*input->rev == tree->first);
+            return {std::move(tree->second), input};
+        }
 
         // FIXME: check whether rev is an ancestor of ref.
 
@@ -354,13 +360,12 @@ struct GitInput : Input
             .actualPath = store->toRealPath(store->printStorePath(storePath)),
             .storePath = std::move(storePath),
             .info = TreeInfo {
-                .rev = input->rev,
                 .revCount = revCount,
                 .lastModified = lastModified
             }
         };
 
-        cacheGitInfo(*store, name, tree);
+        cacheGitInfo(*store, name, tree, *input->rev);
 
         return {std::move(tree), input};
     }

src/libstore/fetchers/github.cc

@@ -114,7 +114,6 @@ struct GitHubInput : Input
             .actualPath = dresult.path,
             .storePath = store->parseStorePath(dresult.storePath),
             .info = TreeInfo {
-                .rev = *rev,
                 .lastModified = *dresult.lastModified,
             },
         };

src/libstore/fetchers/mercurial.cc

@@ -220,7 +220,6 @@ struct MercurialInput : Input
                         .actualPath = store->printStorePath(storePath),
                         .storePath = std::move(storePath),
                         .info = TreeInfo {
-                            .rev = input->rev,
                             .revCount = revCount,
                         },
                     },
@@ -256,7 +255,6 @@ struct MercurialInput : Input
                 .actualPath = store->printStorePath(storePath),
                 .storePath = std::move(storePath),
                 .info = TreeInfo {
-                    .rev = input->rev,
                     .revCount = revCount
                 }
             },

src/libstore/fetchers/tree-info.hh

@@ -5,7 +5,6 @@ namespace nix {
 struct TreeInfo
 {
     Hash narHash;
-    std::optional<Hash> rev; // FIXME: remove
     std::optional<uint64_t> revCount;
     std::optional<time_t> lastModified;
 
@@ -13,7 +12,6 @@ struct TreeInfo
     {
         return
             narHash == other.narHash
-            && rev == other.rev
             && revCount == other.revCount
             && lastModified == other.lastModified;
     }

src/nix/flake.cc

@@ -84,8 +84,8 @@ static void printFlakeInfo(const Store & store, const Flake & flake)
     if (flake.description)
         std::cout << fmt("Description:   %s\n", *flake.description);
     std::cout << fmt("Path:          %s\n", store.printStorePath(flake.sourceInfo->storePath));
-    if (flake.sourceInfo->info.rev)
+    if (auto rev = flake.resolvedRef.input->getRev())
-        std::cout << fmt("Revision:      %s\n", flake.sourceInfo->info.rev->to_string(Base16, false));
+        std::cout << fmt("Revision:      %s\n", rev->to_string(Base16, false));
     if (flake.sourceInfo->info.revCount)
         std::cout << fmt("Revisions:     %s\n", *flake.sourceInfo->info.revCount);
     if (flake.sourceInfo->info.lastModified)
@@ -100,8 +100,8 @@ static nlohmann::json flakeToJson(const Store & store, const Flake & flake)
         j["description"] = *flake.description;
     j["edition"] = flake.edition;
     j["url"] = flake.resolvedRef.input->to_string();
-    if (flake.sourceInfo->info.rev)
+    if (auto rev = flake.resolvedRef.input->getRev())
-        j["revision"] = flake.sourceInfo->info.rev->to_string(Base16, false);
+        j["revision"] = rev->to_string(Base16, false);
     if (flake.sourceInfo->info.revCount)
         j["revCount"] = *flake.sourceInfo->info.revCount;
     if (flake.sourceInfo->info.lastModified)