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[6.0] Fix Windows symlink handling in FileManager APIs #865

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Merged
merged 1 commit into from
Aug 16, 2024
Merged

[6.0] Fix Windows symlink handling in FileManager APIs #865

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23 changes: 17 additions & 6 deletions Sources/FoundationEssentials/FileManager/FileManager+Basics.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -85,14 +85,14 @@ internal struct _FileManagerImpl {
) -> Bool {
#if os(Windows)
return (try? path.withNTPathRepresentation {
let hLHS = CreateFileW($0, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nil, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, nil)
let hLHS = CreateFileW($0, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nil, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, nil)
if hLHS == INVALID_HANDLE_VALUE {
return false
}
defer { CloseHandle(hLHS) }

return (try? other.withNTPathRepresentation {
let hRHS = CreateFileW($0, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nil, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, nil)
let hRHS = CreateFileW($0, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, nil, OPEN_EXISTING, FILE_FLAG_OPEN_REPARSE_POINT | FILE_FLAG_BACKUP_SEMANTICS, nil)
if hRHS == INVALID_HANDLE_VALUE {
return false
}
Expand Down Expand Up @@ -129,11 +129,21 @@ internal struct _FileManagerImpl {
return false
}

if fbiLHS.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT,
fbiRHS.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT {
let lhsIsReparsePoint = fbiLHS.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT
let rhsIsReparsePoint = fbiRHS.FileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT
let lhsIsDirectory = fbiLHS.FileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY
let rhsIsDirectory = fbiRHS.FileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY

guard lhsIsReparsePoint == rhsIsReparsePoint, lhsIsDirectory == rhsIsDirectory else {
// If they aren't the same "type", then they cannot be equivalent
return false
}

if lhsIsReparsePoint {
// Both are symbolic links, so they are equivalent if their destinations are equivalent
return (try? fileManager.destinationOfSymbolicLink(atPath: path) == fileManager.destinationOfSymbolicLink(atPath: other)) ?? false
} else if fbiLHS.FileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY,
fbiRHS.FileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY {
} else if lhsIsDirectory {
// Both are directories, so recursively compare the directories
guard let aLHSItems = try? fileManager.contentsOfDirectory(atPath: path),
let aRHSItems = try? fileManager.contentsOfDirectory(atPath: other),
aLHSItems == aRHSItems else {
Expand All @@ -160,6 +170,7 @@ internal struct _FileManagerImpl {

return true
} else {
// Both must be standard files, so binary compare the contents of the files
var liLHSSize: LARGE_INTEGER = .init()
var liRHSSize: LARGE_INTEGER = .init()
guard GetFileSizeEx(hLHS, &liLHSSize), GetFileSizeEx(hRHS, &liRHSSize), LARGE_INTEGER._equals(liLHSSize, liRHSSize) else {
Expand Down
15 changes: 12 additions & 3 deletions Sources/FoundationEssentials/FileManager/FileOperations.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -807,7 +807,16 @@ enum _FileOperations {
guard delegate.shouldPerformOnItemAtPath(src, to: dst) else { return }

try dst.withNTPathRepresentation { pwszDestination in
if faAttributes.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY {
// Check for reparse points first because symlinks to directories are reported as both reparse points and directories, and we should copy the symlink not the contents of the linked directory
if faAttributes.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT {
do {
let linkDest = try fileManager.destinationOfSymbolicLink(atPath: src)
try fileManager.createSymbolicLink(atPath: dst, withDestinationPath: linkDest)
} catch {
try delegate.throwIfNecessary(error, src, dst)
return
}
} else if faAttributes.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY {
do {
try fileManager.createDirectory(atPath: dst, withIntermediateDirectories: true)
} catch {
Expand All @@ -816,10 +825,10 @@ enum _FileOperations {
for item in _Win32DirectoryContentsSequence(path: src, appendSlashForDirectory: true) {
try linkOrCopyFile(src.appendingPathComponent(item.fileName), dst: dst.appendingPathComponent(item.fileName), with: fileManager, delegate: delegate)
}
} else if bCopyFile || faAttributes.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == FILE_ATTRIBUTE_REPARSE_POINT {
} else if bCopyFile {
var ExtendedParameters: COPYFILE2_EXTENDED_PARAMETERS = .init()
ExtendedParameters.dwSize = DWORD(MemoryLayout<COPYFILE2_EXTENDED_PARAMETERS>.size)
ExtendedParameters.dwCopyFlags = COPY_FILE_FAIL_IF_EXISTS | COPY_FILE_COPY_SYMLINK | COPY_FILE_NO_BUFFERING | COPY_FILE_OPEN_AND_COPY_REPARSE_POINT
ExtendedParameters.dwCopyFlags = COPY_FILE_FAIL_IF_EXISTS | COPY_FILE_NO_BUFFERING

if FAILED(CopyFile2(pwszSource, pwszDestination, &ExtendedParameters)) {
try delegate.throwIfNecessary(GetLastError(), src, dst)
Expand Down
22 changes: 22 additions & 0 deletions Tests/FoundationEssentialsTests/FileManager/FileManagerPlayground.swift
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Expand Up @@ -46,6 +46,22 @@ struct File : ExpressibleByStringLiteral, Buildable {
}
}

struct SymbolicLink : Buildable {
fileprivate let name: String
private let destination: String

init(_ name: String, destination: String) {
self.name = name
self.destination = destination
}

fileprivate func build(in path: String, using fileManager: FileManager) throws {
let linkPath = path.appendingPathComponent(name)
let destPath = path.appendingPathComponent(destination)
try fileManager.createSymbolicLink(atPath: linkPath, withDestinationPath: destPath)
}
}

struct Directory : Buildable {
fileprivate let name: String
private let attributes: [FileAttributeKey : Any]?
Expand All @@ -70,11 +86,13 @@ struct FileManagerPlayground {
enum Item : Buildable {
case file(File)
case directory(Directory)
case symbolicLink(SymbolicLink)

fileprivate func build(in path: String, using fileManager: FileManager) throws {
switch self {
case let .file(file): try file.build(in: path, using: fileManager)
case let .directory(dir): try dir.build(in: path, using: fileManager)
case let .symbolicLink(symlink): try symlink.build(in: path, using: fileManager)
}
}
}
Expand All @@ -92,6 +110,10 @@ struct FileManagerPlayground {
static func buildExpression(_ expression: Directory) -> Item {
.directory(expression)
}

static func buildExpression(_ expression: SymbolicLink) -> Item {
.symbolicLink(expression)
}
}

private let directory: Directory
Expand Down
47 changes: 46 additions & 1 deletion Tests/FoundationEssentialsTests/FileManager/FileManagerTests.swift
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Expand Up @@ -214,10 +214,20 @@ final class FileManagerTests : XCTestCase {
File("Baz", contents: randomData())
}
}
Directory("symlinks") {
File("Foo", contents: randomData())
SymbolicLink("LinkToFoo", destination: "Foo")
}
Directory("EmptyDirectory") {}
"EmptyFile"
}.test {
XCTAssertTrue($0.contentsEqual(atPath: "dir1", andPath: "dir1_copy"))
XCTAssertFalse($0.contentsEqual(atPath: "dir1/dir2", andPath: "dir1/dir3"))
XCTAssertFalse($0.contentsEqual(atPath: "dir1", andPath: "dir1_diffdata"))
XCTAssertFalse($0.contentsEqual(atPath: "symlinks/LinkToFoo", andPath: "symlinks/Foo"), "Symbolic link should not be equal to its destination")
XCTAssertFalse($0.contentsEqual(atPath: "symlinks/LinkToFoo", andPath: "EmptyFile"), "Symbolic link should not be equal to an empty file")
XCTAssertFalse($0.contentsEqual(atPath: "symlinks/LinkToFoo", andPath: "EmptyDirectory"), "Symbolic link should not be equal to an empty directory")
XCTAssertFalse($0.contentsEqual(atPath: "symlinks/EmptyDirectory", andPath: "EmptyFile"), "Empty directory should not be equal to empty file")
}
}

Expand Down Expand Up @@ -253,21 +263,30 @@ final class FileManagerTests : XCTestCase {
"Baz"
}
}
Directory("symlinks") {
"Foo"
SymbolicLink("Bar", destination: "Foo")
SymbolicLink("Parent", destination: "..")
}
}.test {
XCTAssertEqual(try $0.subpathsOfDirectory(atPath: "dir1").sorted(), ["dir2", "dir2/Bar", "dir2/Foo", "dir3", "dir3/Baz"])
XCTAssertEqual(try $0.subpathsOfDirectory(atPath: "dir1/dir2").sorted(), ["Bar", "Foo"])
XCTAssertEqual(try $0.subpathsOfDirectory(atPath: "dir1/dir3").sorted(), ["Baz"])

XCTAssertEqual(try $0.subpathsOfDirectory(atPath: "symlinks").sorted(), ["Bar", "Foo", "Parent"])

XCTAssertThrowsError(try $0.subpathsOfDirectory(atPath: "does_not_exist")) {
XCTAssertEqual(($0 as? CocoaError)?.code, .fileReadNoSuchFile)
}

let fullContents = ["dir1", "dir1/dir2", "dir1/dir2/Bar", "dir1/dir2/Foo", "dir1/dir3", "dir1/dir3/Baz"]
let fullContents = ["dir1", "dir1/dir2", "dir1/dir2/Bar", "dir1/dir2/Foo", "dir1/dir3", "dir1/dir3/Baz", "symlinks", "symlinks/Bar", "symlinks/Foo", "symlinks/Parent"]
let cwd = $0.currentDirectoryPath
XCTAssertNotEqual(cwd.last, "/")
let paths = [cwd, "\(cwd)/", "\(cwd)//", ".", "./", ".//"]
for path in paths {
XCTAssertEqual(try $0.subpathsOfDirectory(atPath: path).sorted(), fullContents)
}

}
}

Expand Down Expand Up @@ -345,6 +364,32 @@ final class FileManagerTests : XCTestCase {
XCTAssertEqual($0.delegateCaptures.shouldCopy, [.init("foo", "bar")])
XCTAssertEqual($0.delegateCaptures.shouldProceedAfterCopyError, [.init("foo", "bar", code: .fileWriteFileExists)])
}

try FileManagerPlayground {
"foo"
SymbolicLink("bar", destination: "foo")
}.test(captureDelegateCalls: true) {
XCTAssertTrue($0.delegateCaptures.isEmpty)
try $0.copyItem(atPath: "bar", toPath: "copy")
XCTAssertEqual($0.delegateCaptures.shouldCopy, [.init("bar", "copy")])
XCTAssertEqual($0.delegateCaptures.shouldProceedAfterCopyError, [])
let copyDestination = try $0.destinationOfSymbolicLink(atPath: "copy")
XCTAssertEqual(copyDestination.lastPathComponent, "foo", "Copied symbolic link points at \(copyDestination) instead of foo")
}

try FileManagerPlayground {
Directory("dir") {
"foo"
}
SymbolicLink("link", destination: "dir")
}.test(captureDelegateCalls: true) {
XCTAssertTrue($0.delegateCaptures.isEmpty)
try $0.copyItem(atPath: "link", toPath: "copy")
XCTAssertEqual($0.delegateCaptures.shouldCopy, [.init("link", "copy")])
XCTAssertEqual($0.delegateCaptures.shouldProceedAfterCopyError, [])
let copyDestination = try $0.destinationOfSymbolicLink(atPath: "copy")
XCTAssertEqual(copyDestination.lastPathComponent, "dir", "Copied symbolic link points at \(copyDestination) instead of foo")
}
}

func testCreateSymbolicLinkAtPath() throws {
Expand Down