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authorEelco Dolstra <edolstra@gmail.com>2017-05-15T16·44+0200
committerEelco Dolstra <edolstra@gmail.com>2017-05-15T16·47+0200
commitc05d9ae7a5f72a6575130cf92fb54e3f90d1927d (patch)
tree76f0de541e7d151cd62929969c31f73966dead9c /src/libexpr
parenta2d92bb20e82a0957067ede60e91fab256948b41 (diff)
Disallow outputHash being null or an empty string
Fixes #1384.
Diffstat (limited to 'src/libexpr')
-rw-r--r--src/libexpr/primops.cc9
1 files changed, 5 insertions, 4 deletions
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 615cc8138433..cc23827a17a6 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -534,7 +534,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
     PathSet context;
 
-    string outputHash, outputHashAlgo;
+    std::experimental::optional<std::string> outputHash;
+    std::string outputHashAlgo;
     bool outputHashRecursive = false;
 
     StringSet outputs;
@@ -703,7 +704,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         throw EvalError(format("derivation names are not allowed to end in ‘%1%’, at %2%")
             % drvExtension % posDrvName);
 
-    if (outputHash != "") {
+    if (outputHash) {
         /* Handle fixed-output derivations. */
         if (outputs.size() != 1 || *(outputs.begin()) != "out")
             throw Error(format("multiple outputs are not supported in fixed-output derivations, at %1%") % posDrvName);
@@ -711,13 +712,13 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         HashType ht = parseHashType(outputHashAlgo);
         if (ht == htUnknown)
             throw EvalError(format("unknown hash algorithm ‘%1%’, at %2%") % outputHashAlgo % posDrvName);
-        Hash h = parseHash16or32(ht, outputHash);
+        Hash h = parseHash16or32(ht, *outputHash);
         outputHash = printHash(h);
         if (outputHashRecursive) outputHashAlgo = "r:" + outputHashAlgo;
 
         Path outPath = state.store->makeFixedOutputPath(outputHashRecursive, h, drvName);
         drv.env["out"] = outPath;
-        drv.outputs["out"] = DerivationOutput(outPath, outputHashAlgo, outputHash);
+        drv.outputs["out"] = DerivationOutput(outPath, outputHashAlgo, *outputHash);
     }
 
     else {