throw IOException for invalid file paths provided to FileStream and File.OpenHandle

src/libraries/System.IO.FileSystem/tests/FileStream/ctor_str_fm.cs

@@ -56,6 +56,15 @@ public void MissingDirectory_ThrowsDirectoryNotFound(char trailingChar)
  Assert.Throws<DirectoryNotFoundException>(() => CreateFileStream(path, FileMode.Open));
  }
 
+ [PlatformSpecific(TestPlatforms.Windows)]
+ [Theory]
+ [InlineData(FileMode.Open)]
+ [InlineData(FileMode.Create)]
+ public void InvalidFilePathThrowsIOException(FileMode fileMode)
+ {
+ Assert.Throws<IOException>(() => CreateFileStream(@"\\.\COM56", fileMode));
+ }
+
  public static TheoryData<string> StreamSpecifiers
  {
  get

src/libraries/System.Private.CoreLib/src/System/IO/File.netcoreapp.cs

@@ -18,13 +18,13 @@ public static partial class File
  /// <summary>
  /// Initializes a new instance of the <see cref="Microsoft.Win32.SafeHandles.SafeFileHandle" /> class with the specified path, creation mode, read/write and sharing permission, the access other SafeFileHandles can have to the same file, additional file options and the allocation size.
  /// </summary>
- /// <param name="path">A relative or absolute path for the file that the current <see cref="Microsoft.Win32.SafeHandles.SafeFileHandle" /> instance will encapsulate.</param>
+ /// <param name="path">A relative or absolute path for the file that the current <see cref="SafeFileHandle" /> instance will encapsulate.</param>
  /// <param name="mode">One of the enumeration values that determines how to open or create the file. The default value is <see cref="FileMode.Open" /></param>
  /// <param name="access">A bitwise combination of the enumeration values that determines how the file can be accessed. The default value is <see cref="FileAccess.Read" /></param>
  /// <param name="share">A bitwise combination of the enumeration values that determines how the file will be shared by processes. The default value is <see cref="FileShare.Read" />.</param>
  /// <param name="preallocationSize">The initial allocation size in bytes for the file. A positive value is effective only when a regular file is being created, overwritten, or replaced.
  /// Negative values are not allowed. In other cases (including the default 0 value), it's ignored.</param>
- /// <param name="options">An object that describes optional <see cref="Microsoft.Win32.SafeHandles.SafeFileHandle" /> parameters to use.</param>
+ /// <param name="options">An object that describes optional <see cref="SafeFileHandle" /> parameters to use.</param>
  /// <exception cref="T:System.ArgumentNullException"><paramref name="path" /> is <see langword="null" />.</exception>
  /// <exception cref="T:System.ArgumentException"><paramref name="path" /> is an empty string (""), contains only white space, or contains one or more invalid characters.
  /// -or-
@@ -35,10 +35,12 @@ public static partial class File
  /// <paramref name="mode" />, <paramref name="access" />, or <paramref name="share" /> contain an invalid value.</exception>
  /// <exception cref="T:System.IO.FileNotFoundException">The file cannot be found, such as when <paramref name="mode" /> is <see cref="FileMode.Truncate" /> or <see cref="FileMode.Open" />, and the file specified by <paramref name="path" /> does not exist. The file must already exist in these modes.</exception>
  /// <exception cref="T:System.IO.IOException">An I/O error, such as specifying <see cref="FileMode.CreateNew" /> when the file specified by <paramref name="path" /> already exists, occurred.
- /// -or-
- /// The disk was full (when <paramref name="preallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
- /// -or-
- /// The file was too large (when <paramref name="preallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).</exception>
+ /// -or-
+ /// The disk was full (when <paramref name="preallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
+ /// -or-
+ /// The file was too large (when <paramref name="preallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
+ /// -or-
+ /// <paramref name="path" /> is invalid (points to a device or is too long).</exception>
  /// <exception cref="T:System.Security.SecurityException">The caller does not have the required permission.</exception>
  /// <exception cref="T:System.IO.DirectoryNotFoundException">The specified path is invalid, such as being on an unmapped drive.</exception>
  /// <exception cref="T:System.UnauthorizedAccessException">The <paramref name="access" /> requested is not permitted by the operating system for the specified <paramref name="path" />, such as when <paramref name="access" /> is <see cref="FileAccess.Write" /> or <see cref="FileAccess.ReadWrite" /> and the file or directory is set for read-only access.

src/libraries/System.Private.CoreLib/src/System/IO/FileStream.cs

@@ -148,26 +148,28 @@ public FileStream(string path, FileMode mode, FileAccess access, FileShare share
  }
 
  /// <summary>
- /// Initializes a new instance of the <see cref="System.IO.FileStream" /> class with the specified path, creation mode, read/write and sharing permission, the access other FileStreams can have to the same file, the buffer size, additional file options and the allocation size.
+ /// Initializes a new instance of the <see cref="FileStream" /> class with the specified path, creation mode, read/write and sharing permission, the access other FileStreams can have to the same file, the buffer size, additional file options and the allocation size.
  /// </summary>
- /// <param name="path">A relative or absolute path for the file that the current <see cref="System.IO.FileStream" /> instance will encapsulate.</param>
- /// <param name="options">An object that describes optional <see cref="System.IO.FileStream" /> parameters to use.</param>
+ /// <param name="path">A relative or absolute path for the file that the current <see cref="FileStream" /> instance will encapsulate.</param>
+ /// <param name="options">An object that describes optional <see cref="FileStream" /> parameters to use.</param>
  /// <exception cref="T:System.ArgumentNullException"><paramref name="path" /> or <paramref name="options" /> is <see langword="null" />.</exception>
  /// <exception cref="T:System.ArgumentException"><paramref name="path" /> is an empty string (""), contains only white space, or contains one or more invalid characters.
  /// -or-
  /// <paramref name="path" /> refers to a non-file device, such as <c>CON:</c>, <c>COM1:</c>, <c>LPT1:</c>, etc. in an NTFS environment.</exception>
  /// <exception cref="T:System.NotSupportedException"><paramref name="path" /> refers to a non-file device, such as <c>CON:</c>, <c>COM1:</c>, <c>LPT1:</c>, etc. in a non-NTFS environment.</exception>
- /// <exception cref="T:System.IO.FileNotFoundException">The file cannot be found, such as when <see cref="System.IO.FileStreamOptions.Mode" /> is <see langword="FileMode.Truncate" /> or <see langword="FileMode.Open" />, and the file specified by <paramref name="path" /> does not exist. The file must already exist in these modes.</exception>
- /// <exception cref="T:System.IO.IOException">An I/O error, such as specifying <see langword="FileMode.CreateNew" /> when the file specified by <paramref name="path" /> already exists, occurred.
- /// -or-
- /// The stream has been closed.
- /// -or-
- /// The disk was full (when <see cref="System.IO.FileStreamOptions.PreallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
- /// -or-
- /// The file was too large (when <see cref="System.IO.FileStreamOptions.PreallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).</exception>
+ /// <exception cref="T:System.IO.FileNotFoundException">The file cannot be found, such as when <see cref="FileStreamOptions.Mode" /> is <see cref="FileMode.Truncate" /> or <see cref="FileMode.Open" />, and the file specified by <paramref name="path" /> does not exist. The file must already exist in these modes.</exception>
+ /// <exception cref="T:System.IO.IOException">An I/O error, such as specifying <see cref="FileMode.CreateNew" /> when the file specified by <paramref name="path" /> already exists, occurred.
+ /// -or-
+ /// The stream has been closed.
+ /// -or-
+ /// The disk was full (when <see cref="FileStreamOptions.PreallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
+ /// -or-
+ /// The file was too large (when <see cref="FileStreamOptions.PreallocationSize" /> was provided and <paramref name="path" /> was pointing to a regular file).
+ /// -or-
+ /// <paramref name="path" /> is invalid (points to a device or is too long).</exception>
  /// <exception cref="T:System.Security.SecurityException">The caller does not have the required permission.</exception>
  /// <exception cref="T:System.IO.DirectoryNotFoundException">The specified path is invalid, such as being on an unmapped drive.</exception>
- /// <exception cref="T:System.UnauthorizedAccessException">The <see cref="System.IO.FileStreamOptions.Access" /> requested is not permitted by the operating system for the specified <paramref name="path" />, such as when <see cref="System.IO.FileStreamOptions.Access" /> is <see cref="System.IO.FileAccess.Write" /> or <see cref="System.IO.FileAccess.ReadWrite" /> and the file or directory is set for read-only access.
+ /// <exception cref="T:System.UnauthorizedAccessException">The <see cref="FileStreamOptions.Access" /> requested is not permitted by the operating system for the specified <paramref name="path" />, such as when <see cref="System.IO.FileStreamOptions.Access" /> is <see cref="FileAccess.Write" /> or <see cref="FileAccess.ReadWrite" /> and the file or directory is set for read-only access.
  /// -or-
  /// <see cref="F:System.IO.FileOptions.Encrypted" /> is specified for <see cref="System.IO.FileStreamOptions.Options" /> , but file encryption is not supported on the current platform.</exception>
  /// <exception cref="T:System.IO.PathTooLongException">The specified path, file name, or both exceed the system-defined maximum length. </exception>