8361587: AssertionError in File.listFiles() when path is empty and -esa is enabled

[bplb]

Changes to address File.listFiles invoked on an empty path. This fixes an oversight in #22821.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8361587: AssertionError in File.listFiles() when path is empty and -esa is enabled (Bug - P2)

Reviewers

• Alan Bateman (@AlanBateman - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26224/head:pull/26224
$ git checkout pull/26224

Update a local copy of the PR:
$ git checkout pull/26224
$ git pull https://git.openjdk.org/jdk.git pull/26224/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 26224

View PR using the GUI difftool:
$ git pr show -t 26224

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26224.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back bpb! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@bplb This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8361587: AssertionError in File.listFiles() when path is empty and -esa is enabled

Reviewed-by: alanb

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 69 new commits pushed to the master branch:

• 401af27: 8360459: UNICODE_CASE and character class with non-ASCII range does not match ASCII char
• 38af17d: 8356807: Change log_info(cds) to MetaspaceShared::report_loading_error()
• 820263e: 8360701: Add bailout when the register allocator interference graph grows unreasonably large
• ... and 66 more: https://git.openjdk.org/jdk/compare/a41d35073ee6da0dde4dd731c1ab4c25245d075a...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

@bplb The following label will be automatically applied to this pull request:

• core-libs

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 07: Full - Incremental (8272cdb7)
• 06: Full - Incremental (b0555078)
• 05: Full - Incremental (93e61dc1)
• 04: Full - Incremental (91867701)
• 03: Full - Incremental (2e42c991)
• 02: Full - Incremental (afaa9329)
• 01: Full - Incremental (76b4439c)
• 00: Full (d7d180ff)

[AlanBateman]

The implementation change looks good, just a few minor comments on the test additions.

[bplb]

/integrate

[openjdk]

Going to push as commit eefbfdc.
Since your change was applied there have been 69 commits pushed to the master branch:

• 401af27: 8360459: UNICODE_CASE and character class with non-ASCII range does not match ASCII char
• 38af17d: 8356807: Change log_info(cds) to MetaspaceShared::report_loading_error()
• 820263e: 8360701: Add bailout when the register allocator interference graph grows unreasonably large
• ... and 66 more: https://git.openjdk.org/jdk/compare/a41d35073ee6da0dde4dd731c1ab4c25245d075a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@bplb Pushed as commit eefbfdc.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[bplb]

/backport :jdk25

[openjdk]

@bplb the backport was successfully created on the branch backport-bplb-eefbfdce-jdk25 in my personal fork of openjdk/jdk. To create a pull request with this backport targeting openjdk/jdk:jdk25, just click the following link:

➡️ Create pull request

The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit eefbfdce from the openjdk/jdk repository.

The commit being backported was authored by Brian Burkhalter on 15 Jul 2025 and was reviewed by Alan Bateman.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk:

$ git fetch https://github.com/openjdk-bots/jdk.git backport-bplb-eefbfdce-jdk25:backport-bplb-eefbfdce-jdk25
$ git checkout backport-bplb-eefbfdce-jdk25
# make changes
$ git add paths/to/changed/files
$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk.git backport-bplb-eefbfdce-jdk25

[jaikiran]

Hello Brian, I'm late to this discussion. I think there are a couple of more places in this code which need attention. The private File constructor which has this assert gets invoked from 3 different File.listFiles() methods. One of them has now been fixed in this PR. However, 2 other listFiles() methods continue to exhibit this issue.

I updated the test/jdk/java/io/File/EmptyPath.java with a couple of more test methods:

diff --git a/test/jdk/java/io/File/EmptyPath.java b/test/jdk/java/io/File/EmptyPath.java
index d0c9beddc08..b747c61f5d1 100644
--- a/test/jdk/java/io/File/EmptyPath.java
+++ b/test/jdk/java/io/File/EmptyPath.java
@@ -28,8 +28,10 @@
  */
 
 import java.io.File;
+import java.io.FileFilter;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
+import java.io.FilenameFilter;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.FileStore;
@@ -242,6 +244,19 @@ public void listFiles() throws IOException {
         assertEquals(nioSet, ioSet);
     }
 
+
+    @Test
+    public void listFiles2() throws IOException {
+        final File f = new File("");
+        final File[] files = f.listFiles((FileFilter) null);
+    }
+
+    @Test
+    public void listFiles3() throws IOException {
+        final File f = new File("");
+        final File[] files = f.listFiles((FilenameFilter) null);
+    }
+

These 2 new test methods continue to fail against mainline master which has the changes integrated from this PR:

java.lang.AssertionError
    at java.base/java.io.File.<init>(File.java:267)
    at java.base/java.io.File.listFiles(File.java:1212)
    at EmptyPath.listFiles2(EmptyPath.java:251)
    at java.base/java.lang.reflect.Method.invoke(Method.java:565)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
FAILED     EmptyPath::listFiles2 'listFiles2()' [2ms]
java.lang.AssertionError
    at java.base/java.io.File.<init>(File.java:267)
    at java.base/java.io.File.listFiles(File.java:1180)
    at EmptyPath.listFiles3(EmptyPath.java:257)
    at java.base/java.lang.reflect.Method.invoke(Method.java:565)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1604)
FAILED     EmptyPath::listFiles3 'listFiles3()' [0ms]

[AlanBateman]

Hello Brian, I'm late to this discussion. I think there are a couple of more places in this code which need attention. The private File constructor which has this assert gets invoked from 3 different File.listFiles() methods. One of them has now been fixed in this PR. However, 2 other listFiles() methods continue to exhibit this issue.

@bplb Can you check the test coverage again? Its important that EmptyTest exercises every method.

[bplb]

@bplb Can you check the test coverage again? Its important that EmptyTest exercises every method.

Yes.

[bplb]

Hello Brian, I'm late to this discussion. I think there are a couple of more places in this code which need attention.

Thanks for catching this, @jaikiran. As you no doubt already observed, this has been fixed by #26353 in the mainline and backported by #26361 to JDK 25 before the rampdown phase 2 deadline.

[jaikiran]

Thank you Brian for addressing these issues very quickly.