Fix InMemoryDirectoryInfo path resolution for '..' and relative paths by svick · Pull Request #126320 · dotnet/runtime

svick · 2026-03-30T15:50:49Z

Fix #99691 — InMemoryDirectoryInfo does not work with the .. pattern.

Problem

InMemoryDirectoryInfo.GetDirectory had two bugs:

For .. it combined the path with FullName but passed it as already-normalized, leaving FullName as e.g. /Folder1/.. instead of resolving to the parent directory.
For other relative paths it resolved against the process CWD, ignoring FullName entirely.

GetFile had the same issue as the second case — it resolved relative paths against CWD instead of FullName.

Fix

GetDirectory("..") now uses Path.GetDirectoryName(FullName) to resolve to the parent. An isParentPath flag preserves Name as ".." (needed by the matcher's pattern traversal), matching DirectoryInfoWrapper's approach.
GetDirectory and GetFile for other paths now combine the input with FullName via Path.Combine.

Tests

Converted FileAbstractionsTests from [Fact] to [Theory] with bool useInMemory, so each test exercises both DirectoryInfoWrapper and InMemoryDirectoryInfo.
Added VerifyInMemoryDirectoryInfo_ParentPatternMatches in FunctionalTests — an end-to-end test that uses Matcher with a ../Folder2/** pattern against InMemoryDirectoryInfo.
Enhanced DisposableFileSystem with useInMemory support: when true, no files/directories are created on disk and GetDirectoryInfoBase() returns an InMemoryDirectoryInfo populated from the recorded CreateFile/CreateFiles calls.

dotnet-policy-service · 2026-03-30T15:52:03Z

Tagging subscribers to this area: @dotnet/area-extensions-filesystem
See info in area-owners.md if you want to be subscribed.

GetDirectory had two bugs: - For '..' it combined with FullName but skipped normalization, leaving FullName as e.g. '/Folder1/..' instead of resolving to the parent. - For other relative paths it resolved against the process CWD, ignoring FullName entirely. GetFile had the same issue as the second case above. The fix uses Path.GetDirectoryName for '..' and Path.Combine with FullName for other paths. An isParentPath flag preserves Name as '..' (needed by the matcher's pattern traversal), matching DirectoryInfoWrapper's approach. Also adds test coverage via theories that exercise both DirectoryInfoWrapper and InMemoryDirectoryInfo through the same test logic, and enhances DisposableFileSystem to support in-memory mode. Fixes dotnet#99691 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Fixes path resolution issues in Microsoft.Extensions.FileSystemGlobbing’s InMemoryDirectoryInfo (notably .. traversal and relative path resolution) and extends Microsoft.Extensions.FileProviders.Physical watching behavior to better handle missing roots / mismatched watcher paths, with expanded test coverage across both areas.

Changes:

Correct InMemoryDirectoryInfo.GetDirectory/GetFile to resolve relative paths against the directory’s FullName, and add coverage for ../ pattern traversal.
Enhance physical file watching to handle missing root directories and broader watcher path configurations, plus update polling tokens to observe directory changes.
Expand and refactor tests/utilities to exercise both disk-backed and in-memory abstractions.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/libraries/Microsoft.Extensions.FileSystemGlobbing/src/InMemoryDirectoryInfo.cs	Updates path resolution for `..` and relative paths in the in-memory directory abstraction.
src/libraries/Microsoft.Extensions.FileSystemGlobbing/src/Abstractions/DirectoryInfoWrapper.cs	Refreshes wrapped `DirectoryInfo` before enumeration to avoid stale `Exists` state.
src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/TestUtility/DisposableFileSystem.cs	Adds `useInMemory` mode and a helper to return `DirectoryInfoBase` for both implementations.
src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/FileAbstractionsTests.cs	Converts key tests to run against both `DirectoryInfoWrapper` and `InMemoryDirectoryInfo`.
src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/FunctionalTests.cs	Adds an end-to-end matcher test for `../Folder2/**` against `InMemoryDirectoryInfo`.
src/libraries/Microsoft.Extensions.FileProviders.Physical/src/PhysicalFilesWatcher.cs	Adds missing-root handling via a pending creation watcher and improves token invalidation / root filtering.
src/libraries/Microsoft.Extensions.FileProviders.Physical/src/PollingFileChangeToken.cs	Extends polling to consider directory changes when the file path doesn’t exist.
src/libraries/Microsoft.Extensions.FileProviders.Physical/src/PhysicalFileProvider.cs	Allows roots that don’t exist and adjusts watcher creation to support deferred enabling.
src/libraries/Microsoft.Extensions.FileProviders.Physical/src/Internal/PathUtils.cs	Centralizes path separator handling and improves trailing-slash behavior.
src/libraries/Microsoft.Extensions.FileProviders.Physical/src/Resources/Strings.resx	Adds new resource strings for watcher/root validation errors.
src/libraries/Microsoft.Extensions.FileProviders.Physical/tests/PhysicalFilesWatcherTests.cs	Adds new watcher-mode matrix tests and missing-directory scenarios.
src/libraries/Microsoft.Extensions.FileProviders.Physical/tests/PhysicalFileProviderTests.cs	Refactors a token test and keeps provider/watch behavior covered.
src/libraries/Microsoft.Extensions.Configuration.FileExtensions/src/FileConfigurationSource.cs	Changes file provider resolution to use the file’s directory even if missing.
src/libraries/Microsoft.Extensions.Configuration.FileExtensions/tests/FileConfigurationProviderTest.cs	Adds regression coverage for watching a config file whose parent directory is missing.

src/libraries/Microsoft.Extensions.FileProviders.Physical/tests/PhysicalFileProviderTests.cs

Copilot · 2026-03-30T16:00:09Z

src/libraries/Microsoft.Extensions.FileSystemGlobbing/src/InMemoryDirectoryInfo.cs

+            string? combinedPath = isParentPath ? Path.GetDirectoryName(FullName) : Path.Combine(FullName, path);
+            string? normPath = combinedPath?.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
+            return normPath == null ? null : new InMemoryDirectoryInfo(normPath, _files, true, _comparisonType, isParentPath);


InMemoryDirectoryInfo.GetDirectory currently uses Path.GetDirectoryName(FullName) for "..". For filesystem roots (e.g. "/" or "C:\"), GetDirectoryName returns null, so GetDirectory("..") returns null (and differs from DirectoryInfoWrapper, where ".." from root resolves back to the root). Consider falling back to FullName (or using Path.GetFullPath(Path.Combine(FullName, ".."))) so traversing above root doesn’t unexpectedly stop.

Suggested change

string? combinedPath = isParentPath ? Path.GetDirectoryName(FullName) : Path.Combine(FullName, path);

string? normPath = combinedPath?.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);

return normPath == null ? null : new InMemoryDirectoryInfo(normPath, _files, true, _comparisonType, isParentPath);

string? combinedPath = isParentPath

? Path.GetDirectoryName(FullName) ?? FullName

: Path.Combine(FullName, path);

string? normPath = combinedPath?.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);

return normPath is null ? null : new InMemoryDirectoryInfo(normPath, _files, true, _comparisonType, isParentPath);

Copilot · 2026-03-30T16:00:09Z

src/libraries/Microsoft.Extensions.FileSystemGlobbing/src/InMemoryDirectoryInfo.cs

+            bool isParentPath = string.Equals(path, "..", StringComparison.Ordinal);
+            string? combinedPath = isParentPath ? Path.GetDirectoryName(FullName) : Path.Combine(FullName, path);
+            string? normPath = combinedPath?.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
+            return normPath == null ? null : new InMemoryDirectoryInfo(normPath, _files, true, _comparisonType, isParentPath);


GetDirectory combines FullName with the provided path but doesn’t normalize the result (e.g., via Path.GetFullPath). If the input contains "."/".." segments beyond the special-case "..", the resulting FullName can be non-canonical and won’t match the normalized paths stored in _files, breaking enumeration/matching. Consider normalizing the combined path before constructing the child InMemoryDirectoryInfo.

Copilot · 2026-03-30T16:00:09Z

src/libraries/Microsoft.Extensions.FileSystemGlobbing/src/InMemoryDirectoryInfo.cs

        {
-            string normPath = Path.GetFullPath(path.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar));
+            string combinedPath = Path.Combine(FullName, path);
+            string normPath = combinedPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);


GetFile builds a combined path via Path.Combine + separator replace but doesn’t normalize it (e.g., Path.GetFullPath). Since _files are stored as fully normalized absolute paths, inputs containing "."/".." segments (or other non-canonical forms) won’t be found. Consider normalizing the combined path before comparing to entries in _files.

Suggested change

string normPath = combinedPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);

string normPath = Path.GetFullPath(combinedPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar));

src/libraries/Microsoft.Extensions.FileProviders.Physical/src/PhysicalFilesWatcher.cs

src/libraries/Microsoft.Extensions.FileProviders.Physical/tests/PhysicalFilesWatcherTests.cs

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Copilot · 2026-03-30T16:57:22Z

src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/FileAbstractionsTests.cs

                Assert.Equal(Path.GetFileName(scenario.RootPath), scenario.DirectoryInfo.Name);
                Assert.Equal(scenario.RootPath, scenario.DirectoryInfo.FullName);


With #nullable enable in this file and DisposableFileSystem.DirectoryInfo now being nullable, scenario.DirectoryInfo.Name / .FullName can trigger nullable warnings (possible null dereference) and break the build under warnings-as-errors. Use scenario.DirectoryInfo! consistently here (or assert non-null / refactor to avoid using the nullable property).

Suggested change

Assert.Equal(Path.GetFileName(scenario.RootPath), scenario.DirectoryInfo.Name);

Assert.Equal(scenario.RootPath, scenario.DirectoryInfo.FullName);

Assert.Equal(Path.GetFileName(scenario.RootPath), scenario.DirectoryInfo!.Name);

Assert.Equal(scenario.RootPath, scenario.DirectoryInfo!.FullName);

Copilot · 2026-03-30T16:57:23Z

src/libraries/Microsoft.Extensions.FileSystemGlobbing/tests/FileAbstractionsTests.cs

        [Fact]
        public void FoldersAreEnumerated()
        {
            using (var scenario = new DisposableFileSystem()
                .CreateFolder("beta"))
            {
-                var contents1 = new DirectoryInfoWrapper(scenario.DirectoryInfo).EnumerateFileSystemInfos();
+                var contents1 = scenario.GetDirectoryInfoBase().EnumerateFileSystemInfos();
                var beta = contents1.OfType<DirectoryInfoBase>().Single();


PR description says FileAbstractionsTests were converted so each test exercises both DirectoryInfoWrapper and InMemoryDirectoryInfo, but FoldersAreEnumerated is still a single [Fact] using the default (disk-backed) DisposableFileSystem(). Either convert this test to a [Theory] like the others (and make DisposableFileSystem record empty directories for in-memory), or adjust the PR description accordingly.

Copilot AI review requested due to automatic review settings March 30, 2026 15:50

github-actions bot added the area-Extensions-FileSystem label Mar 30, 2026

dotnet-policy-service bot assigned svick Mar 30, 2026

Copilot started reviewing on behalf of svick March 30, 2026 15:52 View session

Copilot AI reviewed Mar 30, 2026

View reviewed changes

svick force-pushed the inmemory-go-up branch from 1dcaa87 to 3b6fe23 Compare March 30, 2026 16:07

Addressed review comments and other changes

7c13287

Copilot AI review requested due to automatic review settings March 30, 2026 16:48

Copilot started reviewing on behalf of svick March 30, 2026 16:49 View session

Copilot AI reviewed Mar 30, 2026

View reviewed changes

This was referenced Mar 31, 2026

Unable to pull image from mcr.microsoft.com #117164

Open

XHarness package install failure on iOS due to devicectl NSPOSIXErrorDomain error 49 #123796

Open

Android arm32 device not found (armeabi-v7a architecture unavailable) #125440

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Fix InMemoryDirectoryInfo path resolution for '..' and relative paths#126320

Fix InMemoryDirectoryInfo path resolution for '..' and relative paths#126320
svick wants to merge 2 commits intodotnet:mainfrom
svick:inmemory-go-up

svick commented Mar 30, 2026 •

edited

Loading

Uh oh!

dotnet-policy-service bot commented Mar 30, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Copilot AI Mar 30, 2026

Uh oh!

Copilot AI Mar 30, 2026

Uh oh!

Copilot AI Mar 30, 2026

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 30, 2026

Uh oh!

Copilot AI Mar 30, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

	string normPath = combinedPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar);
	string normPath = Path.GetFullPath(combinedPath.Replace(Path.AltDirectorySeparatorChar, Path.DirectorySeparatorChar));

		Assert.Equal(Path.GetFileName(scenario.RootPath), scenario.DirectoryInfo.Name);
		Assert.Equal(scenario.RootPath, scenario.DirectoryInfo.FullName);

Conversation

svick commented Mar 30, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Problem

Fix

Tests

Uh oh!

dotnet-policy-service bot commented Mar 30, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Copilot AI Mar 30, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 30, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 30, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Mar 30, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 30, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

svick commented Mar 30, 2026 •

edited

Loading