fetchGit: fix submodule output attribute

Before this change it would be false for all evaluations but the first.
Now it follows the input argument (as it should).

2 files changed, 12 insertions, 4 deletions

diff --git a/src/libexpr/primops/fetchGit.cc b/src/libexpr/primops/fetchGit.cc
index 66259d778..653d99b53 100644
--- a/src/libexpr/primops/fetchGit.cc
+++ b/src/libexpr/primops/fetchGit.cc
@@ -32,6 +32,9 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
     std::optional<std::string> ref, std::string rev,
     const std::string & name, bool fetchSubmodules)
 {
+    GitInfo gitInfo;
+    gitInfo.submodules = fetchSubmodules;
+
     if (evalSettings.pureEval && rev == "")
         throw Error("in pure evaluation mode, 'fetchGit' requires a Git revision");
 
@@ -49,7 +52,6 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
         if (!clean) {
 
             /* This is an unclean working tree. So copy all tracked files. */
-            GitInfo gitInfo;
             gitInfo.rev = "0000000000000000000000000000000000000000";
             gitInfo.shortRev = std::string(gitInfo.rev, 0, 7);
 
@@ -141,7 +143,6 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
     }
 
     // FIXME: check whether rev is an ancestor of ref.
-    GitInfo gitInfo;
     gitInfo.rev = rev != "" ? rev : chomp(readFile(localRefFile));
     gitInfo.shortRev = std::string(gitInfo.rev, 0, 7);
 
@@ -190,8 +191,6 @@ GitInfo exportGit(ref<Store> store, const std::string & uri,
                 std::filesystem::remove_all(p.path());
             }
         }
-
-        gitInfo.submodules = true;
     } else {
         auto source = sinkToSource([&](Sink & sink) {
             RunOptions gitOptions("git", { "-C", cacheDir, "archive", gitInfo.rev });
diff --git a/tests/fetchGitSubmodules.sh b/tests/fetchGitSubmodules.sh
index 8ee1bb067..2d625c376 100644
--- a/tests/fetchGitSubmodules.sh
+++ b/tests/fetchGitSubmodules.sh
@@ -61,6 +61,15 @@ r8=$(nix eval --raw "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submo
 [[ $r6 == $r7 ]]
 [[ $r7 == $r8 ]]
 
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; }).submodules")
+[[ $have_submodules == false ]]
+
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submodules = false; }).submodules")
+[[ $have_submodules == false ]]
+
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submodules = true; }).submodules")
+[[ $have_submodules == true ]]
+
 # The resulting store path cannot be the same.
 [[ $pathWithoutSubmodules != $pathWithSubmodules ]]