From 13c557fe823549db75c3dc24c99c46e1c4e1378e Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Wed, 25 Nov 2020 11:20:03 +0100
Subject: [PATCH 1/2] fix the hash rewriting for ca-derivations

---
 src/libstore/build/derivation-goal.cc | 14 ++++++++++++++
 tests/content-addressed.nix           |  9 ++++++---
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index bf2bad62c..0e4504857 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -3121,6 +3121,20 @@ void DerivationGoal::registerOutputs()
             newInfo0.references = refs.second;
             if (refs.first)
                 newInfo0.references.insert(newInfo0.path);
+            if (scratchPath != newInfo0.path) {
+                // Also rewrite the output path
+                auto source = sinkToSource([&](Sink & nextSink) {
+                    StringSink sink;
+                    dumpPath(actualPath, sink);
+                    RewritingSink rsink2(oldHashPart, std::string(newInfo0.path.hashPart()), nextSink);
+                    rsink2((unsigned char *) sink.s->data(), sink.s->size());
+                    rsink2.flush();
+                });
+                Path tmpPath = actualPath + ".tmp";
+                restorePath(tmpPath, *source);
+                deletePath(actualPath);
+                movePath(tmpPath, actualPath);
+            }
 
             assert(newInfo0.ca);
             return newInfo0;
diff --git a/tests/content-addressed.nix b/tests/content-addressed.nix
index 8ca96d4bf..985220f48 100644
--- a/tests/content-addressed.nix
+++ b/tests/content-addressed.nix
@@ -16,14 +16,16 @@ rec {
   };
   rootCA = mkDerivation {
     name = "rootCA";
-    outputs = [ "out" "dev" ];
+    outputs = [ "out" "dev" "foo"];
     buildCommand = ''
       echo "building a CA derivation"
       echo "The seed is ${toString seed}"
       mkdir -p $out
       echo ${rootLegacy}/hello > $out/dep
-      # test symlink at root
+      ln -s $out $out/self
+      # test symlinks at root
       ln -s $out $dev
+      ln -s $out $foo
     '';
     __contentAddressed = true;
     outputHashMode = "recursive";
@@ -34,7 +36,8 @@ rec {
     buildCommand = ''
       echo "building a dependent derivation"
       mkdir -p $out
-      echo ${rootCA}/hello > $out/dep
+      cat ${rootCA}/self/dep
+      echo ${rootCA}/self/dep > $out/dep
     '';
     __contentAddressed = true;
     outputHashMode = "recursive";

From 9bd8184f1fb2e91ac4fb7207abe56f2a30a81d97 Mon Sep 17 00:00:00 2001
From: regnat <rg@regnat.ovh>
Date: Wed, 25 Nov 2020 18:20:35 +0100
Subject: [PATCH 2/2] Allow fixed-output derivations to depend on (floating)
 content-addressed ones

Fix an overlook of https://github.com/NixOS/nix/pull/4056
---
 src/libstore/build/derivation-goal.cc |  4 ++--
 tests/content-addressed.nix           | 11 +++++++++++
 tests/content-addressed.sh            |  1 +
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index 0e4504857..76c49f92c 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -493,8 +493,8 @@ void DerivationGoal::inputsRealised()
     if (useDerivation) {
         auto & fullDrv = *dynamic_cast<Derivation *>(drv.get());
 
-        if ((!fullDrv.inputDrvs.empty() &&
-             fullDrv.type() == DerivationType::CAFloating) || fullDrv.type() == DerivationType::DeferredInputAddressed) {
+        if ((!fullDrv.inputDrvs.empty() && derivationIsCA(fullDrv.type()))
+            || fullDrv.type() == DerivationType::DeferredInputAddressed) {
             /* We are be able to resolve this derivation based on the
                now-known results of dependencies. If so, we become a stub goal
                aliasing that resolved derivation goal */
diff --git a/tests/content-addressed.nix b/tests/content-addressed.nix
index 985220f48..61079176f 100644
--- a/tests/content-addressed.nix
+++ b/tests/content-addressed.nix
@@ -63,4 +63,15 @@ rec {
       echo ${rootCA}/non-ca-hello > $out/dep
     '';
   };
+  dependentFixedOutput = mkDerivation {
+    name = "dependent-fixed-output";
+    outputHashMode = "recursive";
+    outputHashAlgo = "sha256";
+    outputHash = "sha256-QvtAMbUl/uvi+LCObmqOhvNOapHdA2raiI4xG5zI5pA=";
+    buildCommand = ''
+      cat ${dependentCA}/dep
+      echo foo > $out
+    '';
+
+  };
 }
diff --git a/tests/content-addressed.sh b/tests/content-addressed.sh
index bdab09c86..52f7529b5 100644
--- a/tests/content-addressed.sh
+++ b/tests/content-addressed.sh
@@ -40,6 +40,7 @@ testCutoff () {
     #testDerivation dependentCA
     testCutoffFor transitivelyDependentCA
     testCutoffFor dependentNonCA
+    testCutoffFor dependentFixedOutput
 }
 
 testGC () {