Weird behaviour with lists as map keys

[KittyGiraudel]

Maybe follow up of #1169?

$a: 'foo';
$b: 'foo';
$map: (
  $a: 1,
  $b: 2
);

.foo {
  content: $a == $b;
  content: inspect($map);
}

Ruby Sass:

Duplicate key "foo" in map ($a: 1, $b: 2).

LibSass:

.foo {
  content: true;
  content: ("foo": 2);
}

The behaviour is really weird because obviously LibSass spots that it is twice the same key since there is only one key in the output. Although, it does not throw a duplicated key error.

Interestingly enough:

$key: 'foo';
$map: (
  $key: 1,
  $key: 2
);

.foo {
  content: $a == $b;
  content: inspect($map);
}

This yields in LibSass:

Duplicate key "$key" in map ($key: 2). on line 4 at column 10

[xzyfer]

Spec added sass/sass-spec#373

[KittyGiraudel]

You guys rock.