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

@@ -493,8 +493,8 @@ void DerivationGoal::inputsRealised()
     if (useDerivation) {
         auto & fullDrv = *dynamic_cast<Derivation *>(drv.get());
 
-        if ((!fullDrv.inputDrvs.empty() &&
+        if ((!fullDrv.inputDrvs.empty() && derivationIsCA(fullDrv.type()))
-             fullDrv.type() == DerivationType::CAFloating) || fullDrv.type() == DerivationType::DeferredInputAddressed) {
+            || 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 */

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
+    '';
+
+  };
 }

tests/content-addressed.sh

@@ -40,6 +40,7 @@ testCutoff () {
     #testDerivation dependentCA
     testCutoffFor transitivelyDependentCA
     testCutoffFor dependentNonCA
+    testCutoffFor dependentFixedOutput
 }
 
 testGC () {