Support setting ACLs on file paths longer than MAX_PATH (#92460)

Co-authored-by: Adam Sitnik <adam.sitnik@gmail.com>
dotnet · Sep 22, 2023 · 2f7276e · 2f7276e
1 parent fcb9ad9
commit 2f7276e
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Showing 2 changed files with 20 additions and 1 deletion.
diff --git a/...ystem.IO.FileSystem.AccessControl/src/System/Security/AccessControl/FileSystemSecurity.cs b/...ystem.IO.FileSystem.AccessControl/src/System/Security/AccessControl/FileSystemSecurity.cs
@@ -121,7 +121,7 @@ internal void Persist(string fullPath)
             try
             {
                 AccessControlSections persistRules = GetAccessControlSectionsFromChanges();
-                base.Persist(fullPath, persistRules);
+                base.Persist(PathInternal.EnsureExtendedPrefixIfNeeded(fullPath), persistRules);
                 OwnerModified = GroupModified = AuditRulesModified = AccessRulesModified = false;
             }
             finally

diff --git a/src/libraries/System.IO.FileSystem.AccessControl/tests/FileSystemAclExtensionsTests.cs b/src/libraries/System.IO.FileSystem.AccessControl/tests/FileSystemAclExtensionsTests.cs
@@ -143,6 +143,25 @@ public void SetAccessControl_FileInfo_FileSecurity_Success()
             fileInfo.SetAccessControl(fileSecurity);
         }
 
+        [Fact]
+        public void SetAccessControl_FileInfo_FileSecurity_Success_NameLongerThanMaxShortPath()
+        {
+            using var directory = new TempAclDirectory();
+
+            const int MaxShortPath = 260;
+            int fileNameLength = Math.Max(MaxShortPath - directory.Path.Length, 1);
+
+            string path = Path.Combine(directory.Path, new string('1', fileNameLength) + ".txt");
+            using var file = new TempFile(path, 1);
+            var fileInfo = new FileInfo(file.Path);
+            FileSecurity fileSecurity = fileInfo.GetAccessControl(AccessControlSections.Access);
+
+            var newAccessRule = new FileSystemAccessRule(Helpers.s_NetworkServiceNTAccount, FileSystemRights.Write, AccessControlType.Allow);
+            fileSecurity.SetAccessRule(newAccessRule);
+
+            fileInfo.SetAccessControl(fileSecurity);
+        }
+
         [Fact]
         public void SetAccessControl_FileStream_FileSecurity_InvalidArguments()
         {