From c945f015de2149233c1e4fa1628f05567f3657ba Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Wed, 2 Oct 2013 15:24:45 +0200 Subject: [PATCH] Fix segfault in nix-repl / hydra-eval-jobs If a "with" attribute set fails to evaluate, we have to make sure its Env record remains unchanged. Otherwise, repeated evaluation gives a segfault: nix-repl> :a with 0; { a = x; b = x; } Added 2 variables. nix-repl> a error: value is an integer while an attribute set was expected nix-repl> b Segmentation fault --- src/libexpr/eval.cc | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index af2bf92e3..050991a1b 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -319,9 +319,9 @@ inline Value * EvalState::lookupVar(Env * env, const VarRef & var, bool noEval) while (1) { if (!env->haveWithAttrs) { if (noEval) return 0; - Expr * attrs = (Expr *) env->values[0]; - env->values[0] = allocValue(); - evalAttrs(*env->up, attrs, *env->values[0]); + Value * v = allocValue(); + evalAttrs(*env->up, (Expr *) env->values[0], *v); + env->values[0] = v; env->haveWithAttrs = true; } Bindings::iterator j = env->values[0]->attrs->find(var.name);