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diff --git a/js/src/tests/test262/built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-backreferences.js b/js/src/tests/test262/built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-backreferences.js
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+++ b/js/src/tests/test262/built-ins/RegExp/regexp-modifiers/add-ignoreCase-affects-backreferences.js
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+// |reftest| skip -- regexp-modifiers is not supported
+// Copyright 2023 Ron Buckton. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+author: Ron Buckton
+description: >
+  Adding ignoreCase (`i`) modifier in group affects backreferences in group.
+info: |
+  Runtime Semantics: CompileAtom
+  The syntax-directed operation CompileAtom takes arguments direction (forward or backward) and modifiers (a Modifiers Record) and returns a Matcher.
+
+  Atom :: `(` `?` RegularExpressionFlags `:` Disjunction `)`
+    1. Let addModifiers be the source text matched by RegularExpressionFlags.
+    2. Let removeModifiers be the empty String.
+    3. Let newModifiers be UpdateModifiers(modifiers, CodePointsToString(addModifiers), removeModifiers).
+    4. Return CompileSubpattern of Disjunction with arguments direction and newModifiers.
+
+  Atom :: `(` `?` RegularExpressionFlags `-` RegularExpressionFlags `:` Disjunction `)`
+    1. Let addModifiers be the source text matched by the first RegularExpressionFlags.
+    2. Let removeModifiers be the source text matched by the second RegularExpressionFlags.
+    3. Let newModifiers be UpdateModifiers(modifiers, CodePointsToString(addModifiers), CodePointsToString(removeModifiers)).
+    4. Return CompileSubpattern of Disjunction with arguments direction and newModifiers.
+
+  UpdateModifiers ( modifiers, add, remove )
+  The abstract operation UpdateModifiers takes arguments modifiers (a Modifiers Record), add (a String), and remove (a String) and returns a Modifiers. It performs the following steps when called:
+
+  1. Let dotAll be modifiers.[[DotAll]].
+  2. Let ignoreCase be modifiers.[[IgnoreCase]].
+  3. Let multiline be modifiers.[[Multiline]].
+  4. If add contains "s", set dotAll to true.
+  5. If add contains "i", set ignoreCase to true.
+  6. If add contains "m", set multiline to true.
+  7. If remove contains "s", set dotAll to false.
+  8. If remove contains "i", set ignoreCase to false.
+  9. If remove contains "m", set multiline to false.
+  10. Return the Modifiers Record { [[DotAll]]: dotAll, [[IgnoreCase]]: ignoreCase, [[Multiline]]: multiline }.
+
+esid: sec-compileatom
+features: [regexp-modifiers]
+---*/
+
+var re1 = /(a)(?i:\1)/;
+assert(!re1.test("AA"), "a should not match first A");
+assert(!re1.test("Aa"), "a should not match A");
+assert(re1.test("aa"), "a matches first a, so \\1 should match second a");
+assert(re1.test("aA"), "a matches a, so \\1 should match A (ignores case)");
+
+var re2 = /(a)(?i-:\1)/;
+assert(!re2.test("AA"), "a should not match first A");
+assert(!re2.test("Aa"), "a should not match A");
+assert(re2.test("aa"), "a matches first a, so \\1 should match second a");
+assert(re2.test("aA"), "a matches a, so \\1 should match A (ignores case)");
+
+reportCompare(0, 0);