Fix --repair failure on multiple-output derivations

If repair found a corrupted/missing path that depended on a
multiple-output derivation, and some of the outputs of the latter were
not present, it failed with a message like

  error: path ‘/nix/store/cnfn9d5fjys1y93cz9shld2xwaibd7nn-bash-4.3-p42-doc’ is not valid

1 files changed, 3 insertions, 1 deletions

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index b41daac991..931b0755bf 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1123,8 +1123,10 @@ void DerivationGoal::repairClosure()
 
     /* Get the output closure. */
     PathSet outputClosure;
-    for (auto & i : drv->outputs)
+    for (auto & i : drv->outputs) {
+        if (!wantOutput(i.first, wantedOutputs)) continue;
         computeFSClosure(worker.store, i.second.path, outputClosure);
+    }
 
     /* Filter out our own outputs (which we have already checked). */
     for (auto & i : drv->outputs)