Special characters in a branch name causes the extension to fail

In my setup, someone (accidently) created a branch with an umlaut (ö). Even without checking out this branch, the extension fails immediately with the following error:

[Error - 7:52:05 AM] Jun 7, 2023, 7:52:05 AM Initialization failed 
Malformed input or input contains unmappable characters: /workspaces/project/.git/refs/remotes/origin/feature/Sortierungsm��glichkeiten
java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /workspaces/project/.git/refs/remotes/origin/feature/Sortierungsm��glichkeiten
	at java.base/sun.nio.fs.UnixPath.encode(Unknown Source)

Environment

• Operating System: Windows 10 with WSL2 and a VSCode Remote-Container inside WSL2
• JDK version: openjdk 17.0.6 2023-01-17
• Visual Studio Code version: 1.78.2
• Java extension version: v1.19.0

Steps To Reproduce

1. Clone https://github.com/Roemer/java-umlaut-test.git
2. Switch to the branch with a special character: git checkout HelloWörld
3. Open the java file to start the java language server
4. Check the output of Language Support for Java

Current Result

The error occured:

[Error - 9:22:28 AM] Jun 7, 2023, 9:22:28 AM Initialization failed 
Malformed input or input contains unmappable characters: /workspaces/java-umlaut-test/.git/refs/heads/HelloW��rld
java.nio.file.InvalidPathException: Malformed input or input contains unmappable characters: /workspaces/java-umlaut-test/.git/refs/heads/HelloW��rld
	at java.base/sun.nio.fs.UnixPath.encode(Unknown Source)
	at java.base/sun.nio.fs.UnixPath.<init>(Unknown Source)
	at java.base/sun.nio.fs.UnixFileSystem.getPath(Unknown Source)
	at java.base/java.nio.file.Path.of(Unknown Source)
	at java.base/java.nio.file.Paths.get(Unknown Source)
	at org.eclipse.core.internal.filesystem.local.nio.PosixHandler.fetchFileInfo(PosixHandler.java:41)
	at org.eclipse.core.internal.filesystem.local.LocalFileNativesManager.fetchFileInfo(LocalFileNativesManager.java:87)
	at org.eclipse.core.internal.filesystem.local.LocalFile.fetchInfo(LocalFile.java:161)
	at org.eclipse.core.filesystem.provider.FileStore.fetchInfo(FileStore.java:260)
	at org.eclipse.core.filesystem.provider.FileStore.childInfos(FileStore.java:99)
	at org.eclipse.core.internal.localstore.UnifiedTree.getLocalList(UnifiedTree.java:360)
	at org.eclipse.core.internal.localstore.UnifiedTree.addChildren(UnifiedTree.java:148)
	at org.eclipse.core.internal.localstore.UnifiedTree.addNodeChildrenToQueue(UnifiedTree.java:254)
	at org.eclipse.core.internal.localstore.UnifiedTree.accept(UnifiedTree.java:120)
	at org.eclipse.core.internal.localstore.FileSystemResourceManager.refreshResource(FileSystemResourceManager.java:978)
	at org.eclipse.core.internal.localstore.FileSystemResourceManager.refresh(FileSystemResourceManager.java:961)
	at org.eclipse.core.internal.resources.Resource.refreshLocal(Resource.java:1573)
	at org.eclipse.core.internal.resources.Project.open(Project.java:1094)
	at org.eclipse.core.internal.resources.Project.open(Project.java:1150)
	at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.create(ProjectConfigurationManager.java:845)
	at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.lambda$1(ProjectConfigurationManager.java:153)
	at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:394)
	at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:275)
	at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:214)
	at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.importProjects(ProjectConfigurationManager.java:139)
	at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.importProjects(ProjectConfigurationManager.java:130)
	at org.eclipse.jdt.ls.core.internal.managers.MavenProjectImporter.importToWorkspace(MavenProjectImporter.java:241)
	at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager.importProjects(ProjectsManager.java:150)
	at org.eclipse.jdt.ls.core.internal.managers.ProjectsManager.initializeProjects(ProjectsManager.java:112)
	at org.eclipse.jdt.ls.core.internal.handlers.InitHandler$1.runInWorkspace(InitHandler.java:254)
	at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:43)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)

Expected Result

No error occurs

Additional Informations

It seems that this does not happen on Windows, just when using Linux (or WSL2 in my case)

Reproduce the failure with the linked umlaut branch, then start from the stack trace at PosixHandler.fetchFileInfo and follow the project initialization path through MavenProjectImporter and ProjectsManager.initializeProjects. Done means opening the Java project on Linux or WSL2 completes without the InvalidPathException.