more cleanup

(cherry picked from commit c6da1a0)
(cherry picked from commit e0e56a1)

Author: weissi

Foundation/Process.swift

@@ -883,7 +883,8 @@ open class Process: NSObject {
         #else
         for fd in 3 ..< getdtablesize() {
             guard adddup2[fd] == nil &&
-                  !addclose.contains(fd) else {
+                  !addclose.contains(fd) &&
+                  fd != taskSocketPair[1] else {
                     continue // Do not double-close descriptors, or close those pertaining to Pipes or FileHandles we want inherited.
             }
             posix(_CFPosixSpawnFileActionsAddClose(fileActions, fd))

TestFoundation/TestProcess.swift

@@ -750,9 +750,10 @@ class TestProcess : XCTestCase {
         }
     }
 
+    #if !os(Windows)
     func test_fileDescriptorsAreNotInherited() throws {
         let task = Process()
-        let clonedFD = dup(1)
+        let someExtraFDs = [dup(1), dup(1), dup(1), dup(1), dup(1), dup(1), dup(1)]
         task.executableURL = xdgTestHelperURL()
         task.arguments = ["--print-open-file-descriptors"]
         task.standardInput = FileHandle.nullDevice
@@ -761,14 +762,32 @@ class TestProcess : XCTestCase {
         task.standardError = FileHandle.nullDevice
         XCTAssertNoThrow(try task.run())
 
-        try task.run()
         try stdoutPipe.fileHandleForWriting.close()
         let stdoutData = try stdoutPipe.fileHandleForReading.readToEnd()
         task.waitUntilExit()
-        print(String(decoding: stdoutData ?? Data(), as: Unicode.UTF8.self))
-        XCTAssertEqual("0\n1\n2\n", String(decoding: stdoutData ?? Data(), as: Unicode.UTF8.self))
-        close(clonedFD)
-    }
+        let stdoutString = String(decoding: stdoutData ?? Data(), as: Unicode.UTF8.self)
+        #if os(macOS)
+        XCTAssertEqual("0\n1\n2\n", stdoutString)
+        #else
+        // on Linux we may also have a /dev/urandom open as well as some socket that Process uses for something.
+
+        // we should definitely have stdin (0), stdout (1), and stderr (2) open
+        XCTAssert(stdoutString.utf8.starts(with: "0\n1\n2\n".utf8))
+
+        // in total we should have 6 or fewer lines:
+        // 1. stdin
+        // 2. stdout
+        // 3. stderr
+        // 4. /dev/urandom (optional)
+        // 5. communication socket (optional)
+        // 6. trailing new line
+        XCTAssertLessThanOrEqual(stdoutString.components(separatedBy: "\n").count, 6, "\(stdoutString)")
+        #endif
+        for fd in someExtraFDs {
+            close(fd)
+        }
+    }
+    #endif
 
     static var allTests: [(String, (TestProcess) -> () throws -> Void)] {
         var tests = [
@@ -807,6 +826,7 @@ class TestProcess : XCTestCase {
         tests += [
             ("test_interrupt", test_interrupt),
             ("test_suspend_resume", test_suspend_resume),
+            ("test_fileDescriptorsAreNotInherited", test_fileDescriptorsAreNotInherited),
         ]
 #endif
         return tests

TestFoundation/xdgTestHelper/main.swift

@@ -196,6 +196,7 @@ func cat(_ args: ArraySlice<String>.Iterator) {
     exit(exitCode)
 }
 
+#if !os(Windows)
 func printOpenFileDescriptors() {
     for fd in 0..<getdtablesize() {
         if fcntl(fd, F_GETFD) != -1 {
@@ -204,6 +205,7 @@ func printOpenFileDescriptors() {
     }
     exit(0)
 }
+#endif
 
 // -----
 
@@ -263,10 +265,10 @@ case "--nspathfor":
 #if !os(Windows)
 case "--signal-test":
     signalTest()
-#endif
 
 case "--print-open-file-descriptors":
     printOpenFileDescriptors()
+#endif
 
 default:
     fatalError("These arguments are not recognized. Only run this from a unit test.")