From 750bcaa330744be3866c9e0df3f55eaed3de2093 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Mon, 22 Apr 2024 16:41:40 +0200
Subject: [PATCH] Fix fetchGit nested submodules

---
 src/libfetchers/unix/git.cc            |  5 +++
 tests/functional/fetchGitSubmodules.sh | 42 ++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/src/libfetchers/unix/git.cc b/src/libfetchers/unix/git.cc
index 18915c0a7..0c54c5504 100644
--- a/src/libfetchers/unix/git.cc
+++ b/src/libfetchers/unix/git.cc
@@ -642,6 +642,8 @@ struct GitInputScheme : InputScheme
                     attrs.insert_or_assign("ref", submodule.branch);
                 attrs.insert_or_assign("rev", submoduleRev.gitRev());
                 attrs.insert_or_assign("exportIgnore", Explicit<bool>{ exportIgnore });
+                attrs.insert_or_assign("submodules", Explicit<bool>{ true });
+                attrs.insert_or_assign("allRefs", Explicit<bool>{ true });
                 auto submoduleInput = fetchers::Input::fromAttrs(std::move(attrs));
                 auto [submoduleAccessor, submoduleInput2] =
                     submoduleInput.getAccessor(store);
@@ -696,6 +698,9 @@ struct GitInputScheme : InputScheme
                 attrs.insert_or_assign("type", "git");
                 attrs.insert_or_assign("url", submodulePath.abs());
                 attrs.insert_or_assign("exportIgnore", Explicit<bool>{ exportIgnore });
+                attrs.insert_or_assign("submodules", Explicit<bool>{ true });
+                // TODO: fall back to getAccessorFromCommit-like fetch when submodules aren't checked out
+                // attrs.insert_or_assign("allRefs", Explicit<bool>{ true });
 
                 auto submoduleInput = fetchers::Input::fromAttrs(std::move(attrs));
                 auto [submoduleAccessor, submoduleInput2] =
diff --git a/tests/functional/fetchGitSubmodules.sh b/tests/functional/fetchGitSubmodules.sh
index cd180815d..bd82a0a17 100644
--- a/tests/functional/fetchGitSubmodules.sh
+++ b/tests/functional/fetchGitSubmodules.sh
@@ -170,3 +170,45 @@ pathWithSubmodules=$(nix eval --impure --raw --expr "(builtins.fetchGit { url =
 
 [[ -e $pathWithoutExportIgnore/exclude-from-root ]]
 [[ -e $pathWithoutExportIgnore/sub/exclude-from-sub ]]
+
+test_submodule_nested() {
+  local repoA=$TEST_ROOT/submodule_nested/a
+  local repoB=$TEST_ROOT/submodule_nested/b
+  local repoC=$TEST_ROOT/submodule_nested/c
+
+  rm -rf $repoA $repoB $repoC $TEST_HOME/.cache/nix
+
+  initGitRepo $repoC
+  touch $repoC/inside-c
+  git -C $repoC add inside-c
+  addGitContent $repoC
+
+  initGitRepo $repoB
+  git -C $repoB submodule add $repoC c
+  git -C $repoB add c
+  addGitContent $repoB
+
+  initGitRepo $repoA
+  git -C $repoA submodule add $repoB b
+  git -C $repoA add b
+  addGitContent $repoA
+
+
+  # Check non-worktree fetch
+  local rev=$(git -C $repoA rev-parse HEAD)
+  out=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$repoA\"; rev = \"$rev\"; submodules = true; }).outPath")
+  test -e $out/b/c/inside-c
+  test -e $out/content
+  test -e $out/b/content
+  test -e $out/b/c/content
+  local nonWorktree=$out
+
+  # Check worktree based fetch
+  # TODO: make it work without git submodule update
+  git -C $repoA submodule update --init --recursive
+  out=$(nix eval --impure --raw --expr "(builtins.fetchGit { url = \"file://$repoA\"; submodules = true; }).outPath")
+  find $out
+  [[ $out == $nonWorktree ]] || { find $out; false; }
+
+}
+test_submodule_nested