nix copy: Make -r option use the "from" store

Previously, we tried to compute the closure in the local store, which
obviously doesn't work.

3 files changed, 14 insertions, 4 deletions

diff --git a/src/nix/command.cc b/src/nix/command.cc
index 5a8288da9..a1b2c120a 100644
--- a/src/nix/command.cc
+++ b/src/nix/command.cc
@@ -79,9 +79,14 @@ StoreCommand::StoreCommand()
     mkFlag(0, "store", "store-uri", "URI of the Nix store to use", &storeUri);
 }
 
+ref<Store> StoreCommand::createStore()
+{
+    return openStore(storeUri);
+}
+
 void StoreCommand::run()
 {
-    run(openStore(storeUri));
+    run(createStore());
 }
 
 StorePathsCommand::StorePathsCommand()
diff --git a/src/nix/command.hh b/src/nix/command.hh
index a29cdcf7f..fa6c21abf 100644
--- a/src/nix/command.hh
+++ b/src/nix/command.hh
@@ -33,6 +33,7 @@ struct StoreCommand : virtual Command
     std::string storeUri;
     StoreCommand();
     void run() override;
+    virtual ref<Store> createStore();
     virtual void run(ref<Store>) = 0;
 };
 
diff --git a/src/nix/copy.cc b/src/nix/copy.cc
index 083dc3506..b2165cb8f 100644
--- a/src/nix/copy.cc
+++ b/src/nix/copy.cc
@@ -38,13 +38,17 @@ struct CmdCopy : StorePathsCommand
         };
     }
 
-    void run(ref<Store> store, Paths storePaths) override
+    ref<Store> createStore() override
+    {
+        return srcUri.empty() ? StoreCommand::createStore() : openStore(srcUri);
+    }
+
+    void run(ref<Store> srcStore, Paths storePaths) override
     {
         if (srcUri.empty() && dstUri.empty())
             throw UsageError("you must pass ‘--from’ and/or ‘--to’");
 
-        ref<Store> srcStore = srcUri.empty() ? store : openStore(srcUri);
-        ref<Store> dstStore = dstUri.empty() ? store : openStore(dstUri);
+        ref<Store> dstStore = dstUri.empty() ? openStore() : openStore(dstUri);
 
         copyPaths(srcStore, dstStore, PathSet(storePaths.begin(), storePaths.end()));
     }