From 74e68145a2b8fe74cc07ed1c2bd1dbe9219b50f6 Mon Sep 17 00:00:00 2001
From: farfromrefuge <martin.guillon@akylas.fr>
Date: Wed, 2 Aug 2023 03:55:39 +0000
Subject: [PATCH] fix(css): prevent duplicate system classes (#10355)

---
 packages/core/css/system-classes.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/core/css/system-classes.ts b/packages/core/css/system-classes.ts
index cff35f495..3c1edadcb 100644
--- a/packages/core/css/system-classes.ts
+++ b/packages/core/css/system-classes.ts
@@ -12,7 +12,10 @@ export namespace CSSUtils {
 	}
 
 	export function pushToSystemCssClasses(value: string): number {
-		cssClasses.push(value);
+		const index = cssClasses.indexOf(value);
+		if (index == -1) {
+			cssClasses.push(value);
+		}
 
 		return cssClasses.length;
 	}