From 7ac038fa4b83aaeff0b4dcf97b912cd7fd5f0ef6 Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Fri, 11 Jun 2021 09:24:24 +0200
Subject: [PATCH 1/3] Make `computeFSClosure` ca-aware

Fix #4820 by preventing nix-collect garbage from crashing if
`keep-outputs` or `keep-derivations` is true
---
 src/libstore/misc.cc | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index bc5fd968c..3e54bfd8f 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -29,9 +29,9 @@ void Store::computeFSClosure(const StorePathSet & startPaths,
                     res.insert(i);
 
             if (includeDerivers && path.isDerivation())
-                for (auto& i : queryDerivationOutputs(path))
-                    if (isValidPath(i) && queryPathInfo(i)->deriver == path)
-                        res.insert(i);
+                for (auto& [_, maybeOutPath] : queryPartialDerivationOutputMap(path))
+                    if (maybeOutPath && isValidPath(*maybeOutPath) && queryPathInfo(*maybeOutPath)->deriver == path)
+                        res.insert(*maybeOutPath);
             return res;
         };
     else
@@ -44,9 +44,9 @@ void Store::computeFSClosure(const StorePathSet & startPaths,
                     res.insert(ref);
 
             if (includeOutputs && path.isDerivation())
-                for (auto& i : queryDerivationOutputs(path))
-                    if (isValidPath(i))
-                        res.insert(i);
+                for (auto& [_, maybeOutPath] : queryPartialDerivationOutputMap(path))
+                    if (maybeOutPath && isValidPath(*maybeOutPath))
+                        res.insert(*maybeOutPath);
 
             if (includeDerivers && info->deriver && isValidPath(*info->deriver))
                 res.insert(*info->deriver);

From 96d7170e12c75acf363bf7a5a081a86b3c384384 Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Sat, 12 Jun 2021 12:24:53 +0200
Subject: [PATCH 2/3] =?UTF-8?q?Don=E2=80=99t=20check=20the=20`deriver`=20f?=
 =?UTF-8?q?ield=20on=20computeFSClosure?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

That doesn’t really make sense with CA derivations (and wasn’t even
really correct before because of FO derivations, though that probably
didn’t matter much in practice)
---
 src/libstore/misc.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index 3e54bfd8f..48442563f 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -30,7 +30,7 @@ void Store::computeFSClosure(const StorePathSet & startPaths,
 
             if (includeDerivers && path.isDerivation())
                 for (auto& [_, maybeOutPath] : queryPartialDerivationOutputMap(path))
-                    if (maybeOutPath && isValidPath(*maybeOutPath) && queryPathInfo(*maybeOutPath)->deriver == path)
+                    if (maybeOutPath && isValidPath(*maybeOutPath))
                         res.insert(*maybeOutPath);
             return res;
         };

From a3ce88725b44a30184cbe8706fc3a53a8610cc47 Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Tue, 15 Jun 2021 12:11:31 +0200
Subject: [PATCH 3/3] Add a test for the gc with CA derivations

Also add a small architecture to easily run CA-enabled tests
---
 tests/ca/gc.sh      | 12 ++++++++++++
 tests/config.nix.in | 11 ++++++++++-
 tests/local.mk      |  1 +
 3 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100755 tests/ca/gc.sh

diff --git a/tests/ca/gc.sh b/tests/ca/gc.sh
new file mode 100755
index 000000000..e4f9857d6
--- /dev/null
+++ b/tests/ca/gc.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# Ensure that garbage collection works properly with ca derivations
+
+source common.sh
+
+sed -i 's/experimental-features .*/& ca-derivations ca-references/' "$NIX_CONF_DIR"/nix.conf
+
+export NIX_TESTS_CA_BY_DEFAULT=1
+
+cd ..
+source gc.sh
diff --git a/tests/config.nix.in b/tests/config.nix.in
index a57a8c596..9b00d9ddb 100644
--- a/tests/config.nix.in
+++ b/tests/config.nix.in
@@ -1,3 +1,12 @@
+let
+  contentAddressedByDefault = builtins.getEnv "NIX_TESTS_CA_BY_DEFAULT" == "1";
+  caArgs = if contentAddressedByDefault then {
+    __contentAddressed = true;
+    outputHashMode = "recursive";
+    outputHashAlgo = "sha256";
+  } else {};
+in
+
 rec {
   shell = "@bash@";
 
@@ -15,4 +24,4 @@ rec {
       PATH = path;
     } // removeAttrs args ["builder" "meta"])
     // { meta = args.meta or {}; };
-}
+} // caArgs
diff --git a/tests/local.mk b/tests/local.mk
index 59eb4eb0f..e40178b80 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -2,6 +2,7 @@ nix_tests = \
   hash.sh lang.sh add.sh simple.sh dependencies.sh \
   config.sh \
   gc.sh \
+  ca/gc.sh \
   gc-concurrent.sh \
   gc-auto.sh \
   referrers.sh user-envs.sh logging.sh nix-build.sh misc.sh fixed.sh \