From e7c0906521f19b645b2972c38ce94fe32da84c8c Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 5 May 2025 08:28:12 +0200
Subject: [PATCH] Simplify RegisterCommand

---
 src/libcmd/command.cc                 |  4 +---
 src/libcmd/include/nix/cmd/command.hh | 11 +++++++----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/libcmd/command.cc b/src/libcmd/command.cc
index ffb745742..f7aeb739b 100644
--- a/src/libcmd/command.cc
+++ b/src/libcmd/command.cc
@@ -14,12 +14,10 @@
 
 namespace nix {
 
-RegisterCommand::Commands * RegisterCommand::commands = nullptr;
-
 nix::Commands RegisterCommand::getCommandsFor(const std::vector<std::string> & prefix)
 {
     nix::Commands res;
-    for (auto & [name, command] : *RegisterCommand::commands)
+    for (auto & [name, command] : RegisterCommand::commands())
         if (name.size() == prefix.size() + 1) {
             bool equal = true;
             for (size_t i = 0; i < prefix.size(); ++i)
diff --git a/src/libcmd/include/nix/cmd/command.hh b/src/libcmd/include/nix/cmd/command.hh
index 45739fdb2..9139594ac 100644
--- a/src/libcmd/include/nix/cmd/command.hh
+++ b/src/libcmd/include/nix/cmd/command.hh
@@ -285,13 +285,16 @@ struct StorePathCommand : public StorePathsCommand
 struct RegisterCommand
 {
     typedef std::map<std::vector<std::string>, std::function<ref<Command>()>> Commands;
-    static Commands * commands;
+
+    static Commands & commands()
+    {
+        static Commands commands;
+        return commands;
+    }
 
     RegisterCommand(std::vector<std::string> && name, std::function<ref<Command>()> command)
     {
-        if (!commands)
-            commands = new Commands;
-        commands->emplace(name, command);
+        commands().emplace(name, command);
     }
 
     static nix::Commands getCommandsFor(const std::vector<std::string> & prefix);