From 878d82cd226d96dd5c6dd36cdcdd10cdbd963ee8 Mon Sep 17 00:00:00 2001
From: Andrey Sitnik <andrey@sitnik.ru>
Date: Thu, 27 Oct 2022 22:27:10 +0200
Subject: [PATCH] Ignore CSS Custom Properties on prefix in value lookup

---
 lib/declaration.js             | 2 +-
 test/cases/user-select.css     | 4 ++++
 test/cases/user-select.out.css | 6 ++++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/declaration.js b/lib/declaration.js
index 180696b63..0f86c30d2 100644
--- a/lib/declaration.js
+++ b/lib/declaration.js
@@ -33,7 +33,7 @@ class Declaration extends Prefixer {
         continue
       }
       if (value.includes(other)) {
-        return true
+        return value.replace(/var\([^)]+\)/, '').includes(other)
       }
     }
     return false
diff --git a/test/cases/user-select.css b/test/cases/user-select.css
index a48d1fae7..7a97e3e2a 100644
--- a/test/cases/user-select.css
+++ b/test/cases/user-select.css
@@ -9,3 +9,7 @@ b {
 .all {
   user-select: all;
 }
+
+.var {
+  user-select: var(--o-select);
+}
diff --git a/test/cases/user-select.out.css b/test/cases/user-select.out.css
index 24f6a713f..d4e815e1a 100644
--- a/test/cases/user-select.out.css
+++ b/test/cases/user-select.out.css
@@ -14,3 +14,9 @@ b {
   -webkit-user-select: all;
           user-select: all;
 }
+
+.var {
+  -webkit-user-select: var(--o-select);
+      -ms-user-select: var(--o-select);
+          user-select: var(--o-select);
+}