From bfda38f0388ca7fe0c9743d5f4694b159f38da51 Mon Sep 17 00:00:00 2001
From: hanzhe-one <200491821+hanzhe-one@users.noreply.github.com>
Date: Mon, 2 Nov 2026 18:55:32 +0800
Subject: [PATCH 1/2] fix: align unicode case folding with String.regionMatches

---
 .../org/apache/fesod/common/util/StringUtils.java  |  5 +++--
 .../apache/fesod/common/util/StringUtilsTest.java  | 14 ++++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/fesod-common/src/main/java/org/apache/fesod/common/util/StringUtils.java b/fesod-common/src/main/java/org/apache/fesod/common/util/StringUtils.java
index abd801601b..ba71176c5f 100644
--- a/fesod-common/src/main/java/org/apache/fesod/common/util/StringUtils.java
+++ b/fesod-common/src/main/java/org/apache/fesod/common/util/StringUtils.java
@@ -198,8 +198,9 @@ public static boolean regionMatches(
             }
 
             // The same check as in String.regionMatches():
-            if (Character.toUpperCase(c1) != Character.toUpperCase(c2)
-                    && Character.toLowerCase(c1) != Character.toLowerCase(c2)) {
+            final char upper1 = Character.toUpperCase(c1);
+            final char upper2 = Character.toUpperCase(c2);
+            if (upper1 != upper2 && Character.toLowerCase(upper1) != Character.toLowerCase(upper2)) {
                 return false;
             }
         }
diff --git a/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java b/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
index 0f4ec3d0a4..2358198a95 100644
--- a/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
+++ b/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
@@ -211,6 +211,20 @@ boolean invoke() {
         }
     }
 
+    @Test
+    void test_regionMatches_unicodeIgnoreCase() {
+        final CharSequence[] dottedI = {"İ", new StringBuilder("İ")};
+        final CharSequence[] dotlessI = {"ı", new StringBuilder("ı")};
+        for (final CharSequence source : dottedI) {
+            for (final CharSequence other : dotlessI) {
+                Assertions.assertTrue(StringUtils.regionMatches(source, true, 0, other, 0, 1));
+                Assertions.assertTrue(StringUtils.regionMatches(other, true, 0, source, 0, 1));
+                Assertions.assertFalse(StringUtils.regionMatches(source, false, 0, other, 0, 1));
+                Assertions.assertFalse(StringUtils.regionMatches(other, false, 0, source, 0, 1));
+            }
+        }
+    }
+
     @Test
     void stripTest() {
         Assertions.assertNull(StringUtils.strip(null));

From a7b9077082931e1eb79af25aabe9d30163db7c3d Mon Sep 17 00:00:00 2001
From: hanzhe-one <200491821+hanzhe-one@users.noreply.github.com>
Date: Thu, 5 Nov 2026 20:42:54 +0800
Subject: [PATCH 2/2] test: compare unicode region matches against the JDK

---
 .../fesod/common/util/StringUtilsTest.java       | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java b/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
index 2358198a95..52432b99c9 100644
--- a/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
+++ b/fesod-common/src/test/java/org/apache/fesod/common/util/StringUtilsTest.java
@@ -217,10 +217,18 @@ void test_regionMatches_unicodeIgnoreCase() {
         final CharSequence[] dotlessI = {"ı", new StringBuilder("ı")};
         for (final CharSequence source : dottedI) {
             for (final CharSequence other : dotlessI) {
-                Assertions.assertTrue(StringUtils.regionMatches(source, true, 0, other, 0, 1));
-                Assertions.assertTrue(StringUtils.regionMatches(other, true, 0, source, 0, 1));
-                Assertions.assertFalse(StringUtils.regionMatches(source, false, 0, other, 0, 1));
-                Assertions.assertFalse(StringUtils.regionMatches(other, false, 0, source, 0, 1));
+                Assertions.assertEquals(
+                        source.toString().regionMatches(true, 0, other.toString(), 0, 1),
+                        StringUtils.regionMatches(source, true, 0, other, 0, 1));
+                Assertions.assertEquals(
+                        other.toString().regionMatches(true, 0, source.toString(), 0, 1),
+                        StringUtils.regionMatches(other, true, 0, source, 0, 1));
+                Assertions.assertEquals(
+                        source.toString().regionMatches(false, 0, other.toString(), 0, 1),
+                        StringUtils.regionMatches(source, false, 0, other, 0, 1));
+                Assertions.assertEquals(
+                        other.toString().regionMatches(false, 0, source.toString(), 0, 1),
+                        StringUtils.regionMatches(other, false, 0, source, 0, 1));
             }
         }
     }