FileManager: Fix copyItem(atPath:toPath:) for directories and symlinks.

- When copying directories dont recurse into copyItems() just iterate
  through the results of subpathsOfDirectory().

- Copy the contents of the symlink not the file that it points to,
  creating a new symlink.

Author: spevans

Foundation/FileManager.swift

@@ -442,16 +442,34 @@ open class FileManager : NSObject {
             else {
                 return
         }
+
+        func copyNonDirectory(srcPath: String, dstPath: String, fileType: FileAttributeType) throws {
+            if fileType == .typeSymbolicLink {
+                let destination = try destinationOfSymbolicLink(atPath: srcPath)
+                try createSymbolicLink(atPath: dstPath, withDestinationPath: destination)
+            } else if fileType == .typeRegular {
+                if createFile(atPath: dstPath, contents: contents(atPath: srcPath), attributes: nil) == false {
+                    throw NSError(domain: NSCocoaErrorDomain, code: CocoaError.fileWriteUnknown.rawValue, userInfo: [NSFilePathErrorKey : NSString(string: dstPath)])
+                }
+            }
+        }
+
         if fileType == .typeDirectory {
             try createDirectory(atPath: dstPath, withIntermediateDirectories: false, attributes: nil)
             let subpaths = try subpathsOfDirectory(atPath: srcPath)
             for subpath in subpaths {
-                try copyItem(atPath: srcPath + "/" + subpath, toPath: dstPath + "/" + subpath)
+                let src = srcPath + "/" + subpath
+                let dst = dstPath + "/" + subpath
+                if let attrs = try? attributesOfItem(atPath: src), let fileType = attrs[.type] as? FileAttributeType {
+                    if fileType == .typeDirectory {
+                        try createDirectory(atPath: dst, withIntermediateDirectories: false, attributes: nil)
+                    } else {
+                        try copyNonDirectory(srcPath: src, dstPath: dst, fileType: fileType)
+                    }
+                }
             }
         } else {
-            if createFile(atPath: dstPath, contents: contents(atPath: srcPath), attributes: nil) == false {
-                throw NSError(domain: NSCocoaErrorDomain, code: CocoaError.fileWriteUnknown.rawValue, userInfo: [NSFilePathErrorKey : NSString(string: dstPath)])
-            }
+            try copyNonDirectory(srcPath: srcPath, dstPath: dstPath, fileType: fileType)
         }
     }
 

TestFoundation/TestFileManager.swift

@@ -516,7 +516,7 @@ class TestFileManager : XCTestCase {
         let fm = FileManager.default
         let srcPath = NSTemporaryDirectory() + "testdir\(NSUUID().uuidString)"
         let destPath = NSTemporaryDirectory() + "testdir\(NSUUID().uuidString)"
-        
+
         func cleanup() {
             ignoreError { try fm.removeItem(atPath: srcPath) }
             ignoreError { try fm.removeItem(atPath: destPath) }
@@ -552,8 +552,13 @@ class TestFileManager : XCTestCase {
         cleanup()
         createDirectory(atPath: srcPath)
         createDirectory(atPath: "\(srcPath)/tempdir")
+        createDirectory(atPath: "\(srcPath)/tempdir/subdir")
+        createDirectory(atPath: "\(srcPath)/tempdir/subdir/otherdir")
+        createDirectory(atPath: "\(srcPath)/tempdir/subdir/otherdir/extradir")
         createFile(atPath: "\(srcPath)/tempdir/tempfile")
         createFile(atPath: "\(srcPath)/tempdir/tempfile2")
+        createFile(atPath: "\(srcPath)/tempdir/subdir/otherdir/extradir/tempfile2")
+
         do {
             try fm.copyItem(atPath: srcPath, toPath: destPath)
         } catch let error {
@@ -563,16 +568,36 @@ class TestFileManager : XCTestCase {
         XCTAssertTrue(directoryExists(atPath: "\(destPath)/tempdir"))
         XCTAssertTrue(fm.fileExists(atPath: "\(destPath)/tempdir/tempfile"))
         XCTAssertTrue(fm.fileExists(atPath: "\(destPath)/tempdir/tempfile2"))
-        
+        XCTAssertTrue(directoryExists(atPath: "\(destPath)/tempdir/subdir/otherdir/extradir"))
+        XCTAssertTrue(fm.fileExists(atPath: "\(destPath)/tempdir/subdir/otherdir/extradir/tempfile2"))
+
         if (false == directoryExists(atPath: destPath)) {
             return
         }
         do {
             try fm.copyItem(atPath: srcPath, toPath: destPath)
+            XCTFail("Copy overwrites a file/folder that already exists")
         } catch {
-            return
+            // ignore
+        }
+
+        // Test copying a symlink
+        let srcLink = srcPath + "/testlink"
+        let destLink = destPath + "/testlink"
+        do {
+            try fm.createSymbolicLink(atPath: srcLink, withDestinationPath: "linkdest")
+            try fm.copyItem(atPath: srcLink, toPath: destLink)
+            XCTAssertEqual(try fm.destinationOfSymbolicLink(atPath: destLink), "linkdest")
+        } catch {
+            XCTFail("\(error)")
+        }
+
+        do {
+            try fm.copyItem(atPath: srcLink, toPath: destLink)
+            XCTFail("Creating link where one already exists")
+        } catch {
+            // ignore
         }
-        XCTFail("Copy overwrites a file/folder that already exists")
     }
 
     func test_homedirectoryForUser() {