Revert "[dart:io] Backport semantic changes from the dart:io NNBD migration."

This reverts commit 4cd6243d77.

Reason for revert: Breaks anything using the bazel_worker package (which is used for modular compilation with build_runner).  https://travis-ci.org/dart-lang/build/jobs/645748778

Original change's description:
> [dart:io] Backport semantic changes from the dart:io NNBD migration.
> 
> The NNBD migration required making subtle changes to some dart:io
> semantics in order to provide a better API. This change backports these
> semantic changes to the unmigrated SDK so any issues can be discovered
> now instead of blocking the future SDK unfork.
> 
> The Process class will now throw a StateError if the process is detached
> upon accessing the stdin, stdout, stderr, and exitCode getters.
> 
> The Socket class will now throw a SocketException if the socket has been
> destroyed or upgraded to a secure socket upon setting or getting socket
> options.
> 
> Change-Id: I956fd07e713e51ebd479ebbfe4790d8d2fdf0744
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/133989
> Commit-Queue: Jonas Termansen <sortie@google.com>
> Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>

TBR=sortie@google.com,lrn@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I744662fcd14ca232bf44a584bb6f3974d48da69a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134361
Auto-Submit: Jake Macdonald <jakemac@google.com>
Reviewed-by: Jonas Termansen <sortie@google.com>
Commit-Queue: Jonas Termansen <sortie@google.com>

CHANGELOG.md

@@ -17,16 +17,6 @@ used (see Issue [39627][]).
 
 #### `dart:io`
 
-* The `Process` class will now throw a `StateError` if the process is detached
-  upon accessing the `exitCode` getter. It also now throws when the process is
-  detached without stdio upon accessing the `stdin`, `stdout`, and `stderr`
-  getters. Previously these getters would all return `null`.
-
-* The `Socket` class will now throw a `SocketException` if the socket has been
-  destroyed or upgraded to a secure socket upon setting or getting socket
-  options. Previously setting a socket options would be ignored and getting a
-  socket option would return `null`.
-
 ### Dart VM
 
 ### Tools

sdk/lib/_internal/vm/bin/process_patch.dart

@@ -534,16 +534,19 @@ class _ProcessImpl extends _ProcessImplNativeWrapper implements Process {
   _wait(_NativeSocket stdin, _NativeSocket stdout, _NativeSocket stderr,
       _NativeSocket exitHandler) native "Process_Wait";
 
-  Stream<List<int>> get stdout =>
-      _stdout ?? (throw StateError("Process is detached"));
+  Stream<List<int>> get stdout {
+    return _stdout;
+  }
 
-  Stream<List<int>> get stderr =>
-      _stderr ?? (throw StateError("Process is detached"));
+  Stream<List<int>> get stderr {
+    return _stderr;
+  }
 
-  IOSink get stdin => _stdin ?? (throw StateError("Process is detached"));
+  IOSink get stdin {
+    return _stdin;
+  }
 
-  Future<int> get exitCode =>
-      _exitCode?.future ?? (throw StateError("Process is detached"));
+  Future<int> get exitCode => _exitCode != null ? _exitCode.future : null;
 
   bool kill([ProcessSignal signal = ProcessSignal.sigterm]) {
     if (signal is! ProcessSignal) {

sdk/lib/_internal/vm/bin/socket_patch.dart

@@ -1779,37 +1779,40 @@ class _Socket extends Stream<Uint8List> implements Socket {
   }
 
   bool setOption(SocketOption option, bool enabled) {
-    if (_raw == null) throw const SocketException.closed();
+    if (_raw == null) return false;
     return _raw.setOption(option, enabled);
   }
 
   Uint8List getRawOption(RawSocketOption option) {
-    if (_raw == null) throw const SocketException.closed();
+    if (_raw == null) return null;
     return _raw.getRawOption(option);
   }
 
   void setRawOption(RawSocketOption option) {
-    if (_raw == null) throw const SocketException.closed();
-    _raw.setRawOption(option);
+    _raw?.setRawOption(option);
   }
 
   int get port {
     if (_raw == null) throw const SocketException.closed();
+    ;
     return _raw.port;
   }
 
   InternetAddress get address {
     if (_raw == null) throw const SocketException.closed();
+    ;
     return _raw.address;
   }
 
   int get remotePort {
     if (_raw == null) throw const SocketException.closed();
+    ;
     return _raw.remotePort;
   }
 
   InternetAddress get remoteAddress {
     if (_raw == null) throw const SocketException.closed();
+    ;
     return _raw.remoteAddress;
   }
 

sdk/lib/io/socket.dart

@@ -652,29 +652,21 @@ abstract class RawSocket implements Stream<RawSocketEvent> {
 
   /**
    * Returns the port used by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   int get port;
 
   /**
    * Returns the remote port connected to by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   int get remotePort;
 
   /**
    * Returns the [InternetAddress] used to connect this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   InternetAddress get address;
 
   /**
    * Returns the remote [InternetAddress] connected to by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   InternetAddress get remoteAddress;
 
@@ -799,9 +791,6 @@ abstract class Socket implements Stream<Uint8List>, IOSink {
    * available options.
    *
    * Returns [:true:] if the option was set successfully, false otherwise.
-   *
-   * Throws a [SocketException] if the socket has been destroyed or upgraded to
-   * a secure socket.
    */
   bool setOption(SocketOption option, bool enabled);
 
@@ -811,8 +800,7 @@ abstract class Socket implements Stream<Uint8List>, IOSink {
    *
    * Returns the [RawSocketOption.value] on success.
    *
-   * Throws an [OSError] on failure and a [SocketException] if the socket has
-   * been destroyed or upgraded to a secure socket.
+   * Throws an [OSError] on failure.
    */
   Uint8List getRawOption(RawSocketOption option);
 
@@ -820,36 +808,27 @@ abstract class Socket implements Stream<Uint8List>, IOSink {
    * Use [setRawOption] to customize the [RawSocket]. See [RawSocketOption] for
    * available options.
    *
-   * Throws an [OSError] on failure and a [SocketException] if the socket has
-   * been destroyed or upgraded to a secure socket.
+   * Throws an [OSError] on failure.
    */
   void setRawOption(RawSocketOption option);
 
   /**
    * Returns the port used by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   int get port;
 
   /**
    * Returns the remote port connected to by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   int get remotePort;
 
   /**
    * Returns the [InternetAddress] used to connect this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   InternetAddress get address;
 
   /**
    * Returns the remote [InternetAddress] connected to by this socket.
-   *
-   * Throws a [SocketException] if the socket is closed.
    */
   InternetAddress get remoteAddress;
 

sdk_nnbd/lib/_internal/vm/bin/process_patch.dart

@@ -510,7 +510,7 @@ class _ProcessImpl extends _ProcessImplNativeWrapper implements Process {
       _stdout ?? (throw StateError("Process is detached"));
 
   Stream<List<int>> get stderr =>
-      _stderr ?? (throw StateError("Process is detached"));
+      _stdout ?? (throw StateError("Process is detached"));
 
   IOSink get stdin => _stdin ?? (throw StateError("Process is detached"));
 

tests/standalone_2/io/process_detached_test.dart

@@ -12,6 +12,8 @@ import 'dart:io';
 import "package:async_helper/async_helper.dart";
 import "package:expect/expect.dart";
 
+import "process_test_util.dart";
+
 void test() {
   asyncStart();
   var script =
@@ -25,10 +27,10 @@ void test() {
   future.then((process) {
     Expect.isNotNull(process.pid);
     Expect.isTrue(process.pid is int);
-    Expect.throwsStateError(() => process.exitCode);
-    Expect.throwsStateError(() => process.stderr);
-    Expect.throwsStateError(() => process.stdin);
-    Expect.throwsStateError(() => process.stdout);
+    Expect.isNull(process.exitCode);
+    Expect.isNull(process.stderr);
+    Expect.isNull(process.stdin);
+    Expect.isNull(process.stdout);
     Expect.isTrue(process.kill());
   }).whenComplete(() {
     asyncEnd();
@@ -45,7 +47,7 @@ void testWithStdio() {
   future.then((process) {
     Expect.isNotNull(process.pid);
     Expect.isTrue(process.pid is int);
-    Expect.throwsStateError(() => process.exitCode);
+    Expect.isNull(process.exitCode);
     var message = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
     process.stdin.add(message);
     process.stdin.flush().then((_) => process.stdin.close());