Process: Reset the current directory even if the process fails.

Author: spevans

Foundation/Process.swift

@@ -450,16 +450,17 @@ open class Process: NSObject {
             throw _NSErrorWithErrno(errno, reading: true, url: currentDirectoryURL)
         }
 
-        // Launch
+        defer {
+            // Reset the previous working directory path.
+            fileManager.changeCurrentDirectoryPath(previousDirectoryPath)
+        }
 
+        // Launch
         var pid = pid_t()
         guard posix_spawn(&pid, launchPath, &fileActions, nil, argv, envp) == 0 else {
             throw _NSErrorWithErrno(errno, reading: true, path: launchPath)
         }
 
-        // Reset the previous working directory path.
-        fileManager.changeCurrentDirectoryPath(previousDirectoryPath)
-
         // Close the write end of the input and output pipes.
         if let pipe = standardInput as? Pipe {
             pipe.fileHandleForReading.closeFile()

TestFoundation/TestProcess.swift

@@ -289,21 +289,45 @@ class TestProcess : XCTestCase {
     }
 
     func test_run() {
+        let fm = FileManager.default
+        let cwd = fm.currentDirectoryPath
+
         do {
             let process = try Process.run(URL(fileURLWithPath: "/bin/sh", isDirectory: false), arguments: ["-c", "exit 123"], terminationHandler: nil)
             process.waitUntilExit()
             XCTAssertEqual(process.terminationReason, .exit)
             XCTAssertEqual(process.terminationStatus, 123)
         } catch {
-            XCTFail("Cant execute /bin/sh: error")
+            XCTFail("Cant execute /bin/sh: \(error)")
+        }
+        XCTAssertEqual(fm.currentDirectoryPath, cwd)
+
+        do {
+            let process = Process()
+            process.executableURL = URL(fileURLWithPath: "/bin/sh", isDirectory: false)
+            process.arguments = ["-c", "exit 0"]
+            process.currentDirectoryURL = URL(fileURLWithPath: "/.../_no_such_directory", isDirectory: true)
+            try process.run()
+            XCTFail("Executed /bin/sh with invalid currentDirectoryURL")
+            process.terminate()
+            process.waitUntilExit()
+        } catch {
         }
+        XCTAssertEqual(fm.currentDirectoryPath, cwd)
 
         do {
-            let process = try Process.run(URL(fileURLWithPath: "/..", isDirectory: false), arguments: [], terminationHandler: nil)
+            let process = Process()
+            process.executableURL = URL(fileURLWithPath: "/..", isDirectory: false)
+            process.arguments = []
+            process.currentDirectoryURL = URL(fileURLWithPath: "/tmp")
+            try process.run()
             XCTFail("Somehow executed a directory!")
             process.terminate()
+            process.waitUntilExit()
         } catch {
         }
+        XCTAssertEqual(fm.currentDirectoryPath, cwd)
+        fm.changeCurrentDirectoryPath(cwd)
     }
 
 #endif