From 42c9cbf9ca6edad0c4beabee137d3ce6384c42e2 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Thu, 9 Oct 2025 20:53:48 +0200
Subject: [PATCH] Use ref<LockedFlake> where non-null

---
 src/libcmd/include/nix/cmd/installable-flake.hh | 2 +-
 src/libcmd/installable-flake.cc                 | 8 ++++----
 src/libcmd/installables.cc                      | 3 +--
 src/libflake/flake.cc                           | 2 +-
 src/libflake/include/nix/flake/flake.hh         | 2 +-
 src/nix/flake.cc                                | 4 ++--
 6 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/libcmd/include/nix/cmd/installable-flake.hh b/src/libcmd/include/nix/cmd/installable-flake.hh
index f3237c915..9f449ad48 100644
--- a/src/libcmd/include/nix/cmd/installable-flake.hh
+++ b/src/libcmd/include/nix/cmd/installable-flake.hh
@@ -69,7 +69,7 @@ struct InstallableFlake : InstallableValue
      */
     std::vector<ref<eval_cache::AttrCursor>> getCursors(EvalState & state) override;
 
-    std::shared_ptr<flake::LockedFlake> getLockedFlake() const;
+    ref<flake::LockedFlake> getLockedFlake() const;
 
     FlakeRef nixpkgsFlakeRef() const;
 };
diff --git a/src/libcmd/installable-flake.cc b/src/libcmd/installable-flake.cc
index 5431100d3..65f48fa2b 100644
--- a/src/libcmd/installable-flake.cc
+++ b/src/libcmd/installable-flake.cc
@@ -185,16 +185,16 @@ std::vector<ref<eval_cache::AttrCursor>> InstallableFlake::getCursors(EvalState
     return res;
 }
 
-std::shared_ptr<flake::LockedFlake> InstallableFlake::getLockedFlake() const
+ref<flake::LockedFlake> InstallableFlake::getLockedFlake() const
 {
     if (!_lockedFlake) {
         flake::LockFlags lockFlagsApplyConfig = lockFlags;
         // FIXME why this side effect?
         lockFlagsApplyConfig.applyNixConfig = true;
-        _lockedFlake =
-            std::make_shared<flake::LockedFlake>(lockFlake(flakeSettings, *state, flakeRef, lockFlagsApplyConfig));
+        _lockedFlake = make_ref<flake::LockedFlake>(lockFlake(flakeSettings, *state, flakeRef, lockFlagsApplyConfig));
     }
-    return _lockedFlake;
+    // _lockedFlake is now non-null but still just a shared_ptr
+    return ref<flake::LockedFlake>(_lockedFlake);
 }
 
 FlakeRef InstallableFlake::nixpkgsFlakeRef() const
diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
index 7d6ec5199..f0f36378b 100644
--- a/src/libcmd/installables.cc
+++ b/src/libcmd/installables.cc
@@ -342,8 +342,7 @@ void completeFlakeRefWithFragment(
                 parseFlakeRef(fetchSettings, expandTilde(flakeRefS), std::filesystem::current_path().string());
 
             auto evalCache = openEvalCache(
-                *evalState,
-                std::make_shared<flake::LockedFlake>(lockFlake(flakeSettings, *evalState, flakeRef, lockFlags)));
+                *evalState, make_ref<flake::LockedFlake>(lockFlake(flakeSettings, *evalState, flakeRef, lockFlags)));
 
             auto root = evalCache->getRoot();
 
diff --git a/src/libflake/flake.cc b/src/libflake/flake.cc
index b9a2388c7..26b3ef2a0 100644
--- a/src/libflake/flake.cc
+++ b/src/libflake/flake.cc
@@ -954,7 +954,7 @@ std::optional<Fingerprint> LockedFlake::getFingerprint(ref<Store> store, const f
 
 Flake::~Flake() {}
 
-ref<eval_cache::EvalCache> openEvalCache(EvalState & state, std::shared_ptr<LockedFlake> lockedFlake)
+ref<eval_cache::EvalCache> openEvalCache(EvalState & state, ref<LockedFlake> lockedFlake)
 {
     auto fingerprint = state.settings.useEvalCache && state.settings.pureEval
                            ? lockedFlake->getFingerprint(state.store, state.fetchSettings)
diff --git a/src/libflake/include/nix/flake/flake.hh b/src/libflake/include/nix/flake/flake.hh
index ba27bd09e..b3168144c 100644
--- a/src/libflake/include/nix/flake/flake.hh
+++ b/src/libflake/include/nix/flake/flake.hh
@@ -222,7 +222,7 @@ void callFlake(EvalState & state, const LockedFlake & lockedFlake, Value & v);
 /**
  * Open an evaluation cache for a flake.
  */
-ref<eval_cache::EvalCache> openEvalCache(EvalState & state, std::shared_ptr<LockedFlake> lockedFlake);
+ref<eval_cache::EvalCache> openEvalCache(EvalState & state, ref<LockedFlake> lockedFlake);
 
 } // namespace flake
 
diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 18be64bba..cf05f6943 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -1155,7 +1155,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
         evalSettings.enableImportFromDerivation.setDefault(false);
 
         auto state = getEvalState();
-        auto flake = std::make_shared<LockedFlake>(lockFlake());
+        auto flake = make_ref<LockedFlake>(lockFlake());
         auto localSystem = std::string(settings.thisSystem.get());
 
         std::function<bool(eval_cache::AttrCursor & visitor, const std::vector<Symbol> & attrPath, const Symbol & attr)>
@@ -1443,7 +1443,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
             return j;
         };
 
-        auto cache = openEvalCache(*state, flake);
+        auto cache = openEvalCache(*state, ref<flake::LockedFlake>(flake));
 
         auto j = visit(*cache->getRoot(), {}, fmt(ANSI_BOLD "%s" ANSI_NORMAL, flake->flake.lockedRef), "");
         if (json)