From 355a7d91cfe7f8a8d0684e0d432cafebc3454749 Mon Sep 17 00:00:00 2001
From: Ruslan Cheremin <ruslan.cheremin@jetbrains.com>
Date: Sat, 14 Jun 2025 11:43:47 +0200
Subject: [PATCH] [vfs] IDEA-331415: exception for illegal urls

+ throw exception on urls like 'Z:' instead of logging a warning -- such urls shouldn't get to the VFS, but some time ago they somehow sneaked in, so we were forced to deal with them temporary -> hopefully, now they are gone, so we could protect VFS from them

GitOrigin-RevId: 73ab84df3c7f7a26538e463419a9c41ca6fd6387
---
 .../newvfs/persistent/PersistentFSImpl.java   | 10 ++++-----
 .../persistent/PersistentFS_Roots_Test.java   | 21 ++++++++++++-------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
index 8987ece83f09..9f05c61e158a 100644
--- a/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/persistent/PersistentFSImpl.java
@@ -1871,12 +1871,10 @@ public final class PersistentFSImpl extends PersistentFS implements Disposable {
     if (rootUrl.endsWith(":")) {
       if (OSAgnosticPathUtil.startsWithWindowsDrive(rootUrl) && rootUrl.length() == 2) {
         //Workaround for IDEA-331415: it shouldn't happen: rootUrl must be an url (even though sometimes not
-        // fully correct URL), not a win-path -- but it sometimes happens, even though shouldn't:
-        LOG.warn("detectFileSystem[root url='" + rootUrl + "', path='" + rootPath + "']: root URL is not an URL, but Win drive path");
-        return LocalFileSystem.getInstance();
-        //TODO RC: I hope this was just a fluck -- i.e. some VFS instances somehow got 'infected' by these wrong
-        // root urls, but they wash off with time -- and the need for this branch disappears. Lets replace the
-        // workaround with an AssertionError in v24.1, and see.
+        // fully correct URL), not a win-path -- but it sometimes happens, even though shouldn't.
+        // I hope this was just a temporary fluck -- i.e. some VFS instances somehow got 'infected' by these
+        // wrong root urls, but they wash off with time -- and the need for this branch disappears.
+        throw new IllegalArgumentException("detectFileSystem[root url='" + rootUrl + "', path='" + rootPath + "']: root URL is not an URL, but Win drive path");
       }
 
       //We truncated all trailing '/' in the .findRoot(), before putting rootUrl into FSRecords.findOrCreateRoot()
diff --git a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/newvfs/persistent/PersistentFS_Roots_Test.java b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/newvfs/persistent/PersistentFS_Roots_Test.java
index 7ddd9a4ca2ca..d4ce503b480c 100644
--- a/platform/platform-tests/testSrc/com/intellij/openapi/vfs/newvfs/persistent/PersistentFS_Roots_Test.java
+++ b/platform/platform-tests/testSrc/com/intellij/openapi/vfs/newvfs/persistent/PersistentFS_Roots_Test.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.openapi.vfs.newvfs.persistent;
 
 import com.intellij.openapi.vfs.JarFileSystem;
@@ -7,7 +7,8 @@ import com.intellij.openapi.vfs.ex.temp.TempFileSystem;
 import com.intellij.testFramework.junit5.TestApplication;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.fail;
 
 /** Specific tests for VFS roots behavior */
 @TestApplication
@@ -16,11 +17,6 @@ public class PersistentFS_Roots_Test {
 
   @Test
   void detectFileSystem_CorrectlyDetectsFileSystems_ForFewCommonlyUsedUrls() {
-    assertSame(
-      PersistentFSImpl.detectFileSystem("Z:", "Z:"),
-      LocalFileSystem.getInstance(),
-      "Special case: workaround for IDEA-331415 -- likely to be removed after VFS become protected of such roots"
-    );
     assertSame(
       PersistentFSImpl.detectFileSystem("file://Z:", "Z:"),
       LocalFileSystem.getInstance()
@@ -45,4 +41,15 @@ public class PersistentFS_Roots_Test {
     );
   }
 
+  
+  @Test//IDEA-331415
+  void detectFileSystem_FailsOnIncorrectUrl() {
+    try {
+      PersistentFSImpl.detectFileSystem("Z:", "Z:");
+      fail("Windows drive is not a valid URL -> should fail");
+    }
+    catch (IllegalArgumentException e) {
+      //Special case (IDEA-331415): Windows drive is not a valid URL
+    }
+  }
 }