From 36c7b4afc3942318c0c861329bae5e8a75d8f85c Mon Sep 17 00:00:00 2001
From: xzyfer <xzyfer@gmail.com>
Date: Sat, 16 Mar 2019 18:37:56 +1100
Subject: [PATCH] Fix context-exists inside control blocks

It's not enough to check the head of the stack to determine if we're
within a mixin.

Spec https://github.com/sass/sass-spec/pull/1361
Fixes #2842
---
 src/parser.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/parser.cpp b/src/parser.cpp
index c74e15f482..45555816a6 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -2200,7 +2200,8 @@ namespace Sass {
     lex< identifier >();
     std::string name(lexed);
 
-    if (Util::normalize_underscores(name) == "content-exists" && stack.back() != Scope::Mixin)
+    bool in_mixin = std::find(stack.begin(), stack.end(), Scope::Mixin) != stack.end();
+    if (Util::normalize_underscores(name) == "content-exists" && !in_mixin)
     { error("Cannot call content-exists() except within a mixin."); }
 
     ParserState call_pos = pstate;