From 470364b93844ff651b8e02bf8a8b63498d601f6b Mon Sep 17 00:00:00 2001
From: Chenjp <ch_jp@msn.com>
Date: Thu, 21 May 2026 09:58:47 +0800
Subject: [PATCH] =?UTF-8?q?Fix=20implicit=20type=E2=80=91conversion=20prec?=
 =?UTF-8?q?ision=20issues=20in=20equalsIgnoreCase?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

See testcase.
Ascii.toLower(c) implicitly assume c<=0xff.
Now add an explicit check.
---
 java/org/apache/tomcat/util/buf/ByteChunk.java        |  2 +-
 test/org/apache/tomcat/util/buf/TestByteChunk.java    |  8 ++++++++
 test/org/apache/tomcat/util/http/TestMimeHeaders.java | 11 +++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/java/org/apache/tomcat/util/buf/ByteChunk.java b/java/org/apache/tomcat/util/buf/ByteChunk.java
index e9011d5b3062..ec5431e63127 100644
--- a/java/org/apache/tomcat/util/buf/ByteChunk.java
+++ b/java/org/apache/tomcat/util/buf/ByteChunk.java
@@ -705,7 +705,7 @@ public boolean equalsIgnoreCase(String s) {
         }
         int off = start;
         for (int i = 0; i < len; i++) {
-            if (Ascii.toLower(b[off++]) != Ascii.toLower(s.charAt(i))) {
+            if (s.charAt(i) > 0xff || Ascii.toLower(b[off++]) != Ascii.toLower(s.charAt(i))) {
                 return false;
             }
         }
diff --git a/test/org/apache/tomcat/util/buf/TestByteChunk.java b/test/org/apache/tomcat/util/buf/TestByteChunk.java
index ce8234230e84..9fb24f3814eb 100644
--- a/test/org/apache/tomcat/util/buf/TestByteChunk.java
+++ b/test/org/apache/tomcat/util/buf/TestByteChunk.java
@@ -143,6 +143,14 @@ public void testFindBytes() throws UnsupportedEncodingException {
         Assert.assertEquals(-1, ByteChunk.findBytes(bytes, 2, 5, new byte[] { 'w' }));
     }
 
+    @Test
+    public void testEqualsIgnoreCase() {
+        byte[] bytes = "Hello".getBytes();
+        ByteChunk bc = new ByteChunk();
+        bc.setBytes(bytes, 0, bytes.length);
+        Assert.assertTrue(bc.equalsIgnoreCase("heLLo"));
+        Assert.assertFalse(bc.equalsIgnoreCase("\u8a48\u8a65\u8a6c\u8a6c\u8a6f"));
+    }
 
     @Test
     public void testSerialization() throws Exception {
diff --git a/test/org/apache/tomcat/util/http/TestMimeHeaders.java b/test/org/apache/tomcat/util/http/TestMimeHeaders.java
index efc7832bf711..b72c8eacbe32 100644
--- a/test/org/apache/tomcat/util/http/TestMimeHeaders.java
+++ b/test/org/apache/tomcat/util/http/TestMimeHeaders.java
@@ -16,6 +16,7 @@
  */
 package org.apache.tomcat.util.http;
 
+import java.io.UnsupportedEncodingException;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.Set;
@@ -32,6 +33,16 @@ public class TestMimeHeaders {
     public static final String HEADER_NAME_B = "bbb";
     public static final String HEADER_NAME_C = "ccc";
 
+    @Test
+    public void testSetValueBytesIgnoresCase01() throws UnsupportedEncodingException {
+        MimeHeaders mh = new MimeHeaders();
+
+        byte[] bytes = HEADER_NAME_UC_STRING.getBytes("utf-8");
+        mh.setValue(HEADER_NAME_UC_STRING).setBytes(bytes, 0, bytes.length);
+        Assert.assertTrue(mh.getValue(HEADER_NAME_UC_STRING).equalsIgnoreCase(HEADER_NAME_MIXED_STRING));
+        Assert.assertFalse(mh.getValue(HEADER_NAME_UC_STRING).equalsIgnoreCase("\u8a54\u8a45\u8a53\u8a54"));
+    }
+
     @Test
     public void testSetValueStringIgnoresCase01() {
         MimeHeaders mh = new MimeHeaders();