Test {{com/sun/net/httpserver/simpleserver/MapToPathTest.java}} always fails for me on freshly installed Windows 11.

127.0.0.1 - - [06/Feb/2022:19:23:26 +0300] "GET /foo/bar/baz/c:// HTTP/1.1" 200 -
Resource requested: C:\Projects\jdk2\build\windows-x86_64-server-release\test-support\jtreg_test_jdk_com_sun_net_httpserver_simpleserver_MapToPathTest_java\scratch\0\MapToPathTest\foo\bar\baz\
> Connection: Upgrade, HTTP2-Settings
> Http2-settings: AAEAAEAAAAIAAAABAAMAAABkAAQBAAAAAAUAAEAA
> Host: localhost:59664
> Upgrade: h2c
> User-agent: Java-http-client/19-internal
> Content-length: 0
>
< Date: Sun, 06 Feb 2022 16:23:26 GMT
< Last-modified: Sun, 6 Feb 2022 16:23:25 GMT
< Content-type: text/html; charset=UTF-8
< Content-length: 216
<
test MapToPathTest.test(): failure
java.lang.AssertionError: expected [404] but found [200]
        at org.testng.Assert.fail(Assert.java:99)
        at org.testng.Assert.failNotEquals(Assert.java:1037)
        at org.testng.Assert.assertEqualsImpl(Assert.java:140)
        at org.testng.Assert.assertEquals(Assert.java:122)
        at org.testng.Assert.assertEquals(Assert.java:907)
        at org.testng.Assert.assertEquals(Assert.java:917)
        at MapToPathTest.test(MapToPathTest.java:138)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
        at java.base/java.lang.reflect.Method.invoke(Method.java:577)
        at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:132)
        at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:599)
        at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:174)
        at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
        at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:822)
        at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:147)
        at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
        at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
        at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
        at org.testng.TestRunner.privateRun(TestRunner.java:764)
        at org.testng.TestRunner.run(TestRunner.java:585)
        at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
        at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
        at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
        at org.testng.SuiteRunner.run(SuiteRunner.java:286)
        at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
        at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
        at org.testng.TestNG.runSuitesSequentially(TestNG.java:1218)
        at org.testng.TestNG.runSuitesLocally(TestNG.java:1140)
        at org.testng.TestNG.runSuites(TestNG.java:1069)
        at org.testng.TestNG.run(TestNG.java:1037)
        at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:94)
        at com.sun.javatest.regtest.agent.TestNGRunner.main(TestNGRunner.java:54)
        at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104)
        at java.base/java.lang.reflect.Method.invoke(Method.java:577)
        at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
        at java.base/java.lang.Thread.run(Thread.java:828)

On Windows 11 method 'sun.net.httpserver.simpleserver.FileServerHandler#mapToPath'
https://github.com/openjdk/jdk/blob/77b0240d44fd356711d75bc241e198f6f89ada8f/src/jdk.httpserver/share/classes/sun/net/httpserver/simpleserver/FileServerHandler.java#L230
resolves path to 'C:\Projects\jdk2\build\windows-x86_64-server-release\test-support\jtreg_test_jdk_com_sun_net_httpserver_simpleserver_MapToPathTest_java\scratch\0\MapToPathTest\foo\bar\baz\'
(Which seems strange for me). This directory is not hidden and readable. That's why server returns 200.

On Windows 10 (where test does NOT fail) method resolves path as 'c:'. (Which is surprise for me too) and then this path is considered as _hidden_ (why?) inside sun.net.httpserver.simpleserver.FileServerHandler#isHiddenOrSymLink method. And return expected 404.

Looks like main difference is that on Win11 JDK is located in Disk C:. (at path C:\Projects\jdk2), while on Win10 JDK is located in Disk K:. And because of that WindowsPath.resolve returns different result (see https://github.com/openjdk/jdk/blob/master/src/java.base/windows/classes/sun/nio/fs/WindowsPath.java#L628 )