readFile: Check against nul bytes

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index fe2f1b1e0ae1..95914626f1ca 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -749,7 +749,10 @@ static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Va
         throw EvalError(format("cannot read ‘%1%’, since path ‘%2%’ is not valid, at %3%")
             % path % e.path % pos);
     }
-    mkString(v, readFile(state.checkSourcePath(path)).c_str());
+    string s = readFile(state.checkSourcePath(path));
+    if (s.find((char) 0) != string::npos)
+        throw Error(format("the contents of the file ‘%1%’ cannot be represented as a Nix string") % path);
+    mkString(v, s.c_str());
 }