From bece2eb1b4e4206ac07c62d75c457effd93eb491 Mon Sep 17 00:00:00 2001
From: Steven Levithan <steves_list@hotmail.com>
Date: Tue, 27 Oct 2020 17:20:32 -0400
Subject: [PATCH] Work around core-js 3.6.0 incomplete sticky polyfill

---
 src/xregexp.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/xregexp.js b/src/xregexp.js
index f879a256..b7f1e1ad 100644
--- a/src/xregexp.js
+++ b/src/xregexp.js
@@ -70,6 +70,13 @@ function hasNativeFlag(flag) {
     } catch (exception) {
         isSupported = false;
     }
+    // Work around a broken/incomplete IE11 polyfill for sticky introduced in core-js 3.6.0
+    if (flag === 'y') {
+        const incompleteY = '.a'.replace(new RegExp('a', 'gy'), '.') === '..';
+        if (incompleteY) {
+            isSupported = false;
+        }
+    }
     return isSupported;
 }
 // Check for ES6 `u` flag support