From 7327e38b1c767051658e68171994042649a4203a Mon Sep 17 00:00:00 2001
From: Martijn Cuppens <martijn.cuppens@gmail.com>
Date: Sat, 12 Oct 2019 15:07:22 +0200
Subject: [PATCH] Fix top level ampersand (#29518)

Fixes dart sass compatibility.
---
 scss/mixins/_forms.scss | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/scss/mixins/_forms.scss b/scss/mixins/_forms.scss
index 67136bcdb4..cdc5959073 100644
--- a/scss/mixins/_forms.scss
+++ b/scss/mixins/_forms.scss
@@ -26,14 +26,16 @@
   @include deprecate("The `form-control-focus()` mixin", "v4.3.2", "v5", $ignore-warning);
 }
 
+// This mixin uses an `if()` technique to be compatible with Dart Sass
+// See https://github.com/sass/sass/issues/1873#issuecomment-152293725 for more details
 @mixin form-validation-state-selector($state) {
   @if ($state == "valid" or $state == "invalid") {
-    .was-validated &:#{$state},
-    &.is-#{$state} {
+    .was-validated #{if(&, "&", "")}:#{$state},
+    #{if(&, "&", "")}.is-#{$state} {
       @content;
     }
   } @else {
-    &.is-#{$state} {
+    #{if(&, "&", "")}.is-#{$state} {
       @content;
     }
   }