fix regression in mixin scoping

CHANGELOG.md

@@ -1,5 +1,6 @@
 # 0.9.1
- - fix issue in which `@at-root` would panic when placed after a ruleset
+ - fix regression in which `@at-root` would panic when placed after a ruleset
+ - fix regression related to `@mixin` scoping and outer, local variables
 
 # 0.9.0
 

src/parse/mixin.rs

@@ -116,6 +116,8 @@ impl<'a> Parser<'a> {
         }
         .parse()?;
 
+        self.scopes.pop();
+
         Ok(body)
     }
 

tests/mixins.rs

@@ -242,3 +242,8 @@ test!(
     "@mixin c {}\n\na {\n    @include c()\n}\n",
     ""
 );
+test!(
+    local_variable_declared_before_mixin_is_still_in_scope,
+    "@mixin foo {}\n\na {\n    $a: red;\n    @include foo;\n    color: $a;\n}\n",
+    "a {\n  color: red;\n}\n"
+);