From 45e20d8c9e5e3b570cf927eed97923661e9eb440 Mon Sep 17 00:00:00 2001
From: David Perez <david@livefront.com>
Date: Wed, 20 Aug 2025 15:20:03 -0500
Subject: [PATCH] PM-17755: Fix comparator inconsistency based on Locale
 (#5762)

---
 .../SpecialCharWithPrecedenceComparator.kt    |  5 +--
 ...SpecialCharWithPrecedenceComparatorTest.kt | 35 ++++++++++++++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/core/src/main/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparator.kt b/core/src/main/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparator.kt
index 3fcfd8e382..a30a810a6c 100644
--- a/core/src/main/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparator.kt
+++ b/core/src/main/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparator.kt
@@ -38,8 +38,9 @@ private fun compareCharsSpecialCharsWithPrecedence(c1: Char, c2: Char): Int {
         }
 
         else -> {
-            val upperCaseStr1 = c1.toString().uppercase(Locale.getDefault())
-            val upperCaseStr2 = c2.toString().uppercase(Locale.getDefault())
+            // Use Locale.ROOT for consistent, locale-insensitive comparison
+            val upperCaseStr1 = c1.toString().uppercase(Locale.ROOT)
+            val upperCaseStr2 = c2.toString().uppercase(Locale.ROOT)
             upperCaseStr1.compareTo(upperCaseStr2)
         }
     }
diff --git a/core/src/test/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparatorTest.kt b/core/src/test/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparatorTest.kt
index 892c643a5f..00293930fb 100644
--- a/core/src/test/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparatorTest.kt
+++ b/core/src/test/kotlin/com/bitwarden/core/data/repository/util/SpecialCharWithPrecedenceComparatorTest.kt
@@ -1,10 +1,25 @@
 package com.bitwarden.core.data.repository.util
 
-import org.junit.Test
+import org.junit.jupiter.api.AfterEach
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import java.util.Locale
 
 class SpecialCharWithPrecedenceComparatorTest {
 
+    private lateinit var defaultLocale: Locale
+
+    @BeforeEach
+    fun setup() {
+        defaultLocale = Locale.getDefault()
+    }
+
+    @AfterEach
+    fun tearDown() {
+        Locale.setDefault(defaultLocale)
+    }
+
     @Test
     fun `Sorting with comparator should return expected result of sorted string`() {
         val unsortedList = listOf(
@@ -41,4 +56,22 @@ class SpecialCharWithPrecedenceComparatorTest {
             unsortedList.sortedWith(SpecialCharWithPrecedenceComparator),
         )
     }
+
+    @Test
+    fun `comparator should return consistent values across locales`() {
+        val unsortedList = listOf("i", "z", "j")
+        val sortedList = listOf("i", "j", "z")
+        val locales = listOf(
+            Locale.forLanguageTag("tr-TR"),
+            Locale.US,
+        )
+
+        locales.forEach { locale ->
+            Locale.setDefault(locale)
+            assertEquals(
+                sortedList,
+                unsortedList.sortedWith(SpecialCharWithPrecedenceComparator),
+            )
+        }
+    }
 }