From 908e9ce259710037ae9824a3246143e46e27e867 Mon Sep 17 00:00:00 2001 From: Shea Levy Date: Sun, 9 Mar 2014 14:24:47 -0400 Subject: [PATCH] If a dynamic attribute name evaluates to null, remove it from the set --- src/libexpr/eval.cc | 10 +++++++++- tests/lang/eval-okay-null-dynamic-attrs.exp | 1 + tests/lang/eval-okay-null-dynamic-attrs.nix | 1 + 3 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 tests/lang/eval-okay-null-dynamic-attrs.exp create mode 100644 tests/lang/eval-okay-null-dynamic-attrs.nix diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc index 350a4fbe..730b431c 100644 --- a/src/libexpr/eval.cc +++ b/src/libexpr/eval.cc @@ -642,7 +642,15 @@ void ExprAttrs::eval(EvalState & state, Env & env, Value & v) /* dynamic attrs apply *after* rec and __overrides */ foreach (DynamicAttrDefs::iterator, i, dynamicAttrs) { Value nameVal; - i->nameExpr->eval(state, *dynamicEnv, nameVal); + assert(dynamic_cast(i->nameExpr)); + ExprConcatStrings * nameExpr = static_cast(i->nameExpr); + if (nameExpr->es->size() == 1) { + nameExpr->es->front()->eval(state, *dynamicEnv, nameVal); + state.forceValue(nameVal); + if (nameVal.type == tNull) + continue; + } + nameExpr->eval(state, *dynamicEnv, nameVal); state.forceStringNoCtx(nameVal); Symbol nameSym = state.symbols.create(nameVal.string.s); Bindings::iterator j = v.attrs->find(nameSym); diff --git a/tests/lang/eval-okay-null-dynamic-attrs.exp b/tests/lang/eval-okay-null-dynamic-attrs.exp new file mode 100644 index 00000000..27ba77dd --- /dev/null +++ b/tests/lang/eval-okay-null-dynamic-attrs.exp @@ -0,0 +1 @@ +true diff --git a/tests/lang/eval-okay-null-dynamic-attrs.nix b/tests/lang/eval-okay-null-dynamic-attrs.nix new file mode 100644 index 00000000..b060c0bc --- /dev/null +++ b/tests/lang/eval-okay-null-dynamic-attrs.nix @@ -0,0 +1 @@ +{ ${null} = true; } == {}