win,tty: fix read stop in line mode

Closing the handle does not make ReadConsoleW exit reliably on
Windows 7 and above. Thus, after switching from line to raw mode,
keypresses were held until enter was pressed. This makes ReadConsoleW
exit by writing a return keypress to its input buffer, similar to
what was already done for raw mode.

Fixes: https://github.com/libuv/libuv/issues/852
PR-URL: https://github.com/libuv/libuv/pull/866
Reviewed-by: Bert Belder <bertbelder@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>

configure.ac

@@ -59,7 +59,7 @@ AM_CONDITIONAL([OPENBSD],  [AS_CASE([$host_os],[openbsd*],      [true], [false])
 AM_CONDITIONAL([SUNOS],    [AS_CASE([$host_os],[solaris*],      [true], [false])])
 AM_CONDITIONAL([WINNT],    [AS_CASE([$host_os],[mingw*],        [true], [false])])
 AS_CASE([$host_os],[mingw*], [
-    LIBS="$LIBS -lws2_32 -lpsapi -liphlpapi -lshell32 -luserenv"
+    LIBS="$LIBS -lws2_32 -lpsapi -liphlpapi -lshell32 -luserenv -luser32"
 ])
 AC_CHECK_HEADERS([sys/ahafs_evProds.h])
 AC_CHECK_PROG(PKG_CONFIG, pkg-config, yes)

src/win/internal.h

@@ -83,6 +83,7 @@ extern UV_THREAD_LOCAL int uv__crt_assert_enabled;
 #define UV_HANDLE_ZERO_READ                     0x00080000
 #define UV_HANDLE_EMULATE_IOCP                  0x00100000
 #define UV_HANDLE_BLOCKING_WRITES               0x00200000
+#define UV_HANDLE_CANCELLATION_PENDING          0x00400000
 
 /* Used by uv_tcp_t and uv_udp_t handles */
 #define UV_HANDLE_IPV6                          0x01000000

src/win/tty.c

@@ -871,10 +871,15 @@ void uv_process_tty_read_line_req(uv_loop_t* loop, uv_tty_t* handle,
     }
 
   } else {
-    /* Read successful */
-    /* TODO: read unicode, convert to utf-8 */
-    DWORD bytes = req->u.io.overlapped.InternalHigh;
-    handle->read_cb((uv_stream_t*) handle, bytes, &buf);
+    if (!(handle->flags & UV_HANDLE_CANCELLATION_PENDING)) {
+      /* Read successful */
+      /* TODO: read unicode, convert to utf-8 */
+      DWORD bytes = req->u.io.overlapped.InternalHigh;
+      handle->read_cb((uv_stream_t*) handle, bytes, &buf);
+    } else {
+      handle->flags &= ~UV_HANDLE_CANCELLATION_PENDING;
+      handle->read_cb((uv_stream_t*) handle, 0, &buf);
+    }
   }
 
   /* Wait for more input events. */
@@ -937,6 +942,9 @@ int uv_tty_read_start(uv_tty_t* handle, uv_alloc_cb alloc_cb,
 
 
 int uv_tty_read_stop(uv_tty_t* handle) {
+  INPUT_RECORD record;
+  DWORD written;
+
   handle->flags &= ~UV_HANDLE_READING;
   DECREASE_ACTIVE_COUNT(handle->loop, handle);
 
@@ -944,8 +952,6 @@ int uv_tty_read_stop(uv_tty_t* handle) {
   if ((handle->flags & UV_HANDLE_READ_PENDING) &&
       (handle->flags & UV_HANDLE_TTY_RAW)) {
     /* Write some bullshit event to force the console wait to return. */
-    INPUT_RECORD record;
-    DWORD written;
     memset(&record, 0, sizeof record);
     if (!WriteConsoleInputW(handle->handle, &record, 1, &written)) {
       return GetLastError();
@@ -954,7 +960,20 @@ int uv_tty_read_stop(uv_tty_t* handle) {
 
   /* Cancel line-buffered read */
   if (handle->tty.rd.read_line_handle != NULL) {
-    /* Closing this handle will cancel the ReadConsole operation */
+    if (!(handle->flags & UV_HANDLE_CANCELLATION_PENDING)) {
+      /* Write enter key event to force the console wait to return. */
+      record.EventType = KEY_EVENT;
+      record.Event.KeyEvent.bKeyDown = TRUE;
+      record.Event.KeyEvent.wRepeatCount = 1;
+      record.Event.KeyEvent.wVirtualKeyCode = VK_RETURN;
+      record.Event.KeyEvent.wVirtualScanCode =
+        MapVirtualKeyW(VK_RETURN, MAPVK_VK_TO_VSC);
+      record.Event.KeyEvent.uChar.UnicodeChar = L'\r';
+      record.Event.KeyEvent.dwControlKeyState = 0;
+      WriteConsoleInputW(handle->handle, &record, 1, &written);
+      handle->flags |= UV_HANDLE_CANCELLATION_PENDING;
+    }
+    /* Close line-buffered read handle */
     CloseHandle(handle->tty.rd.read_line_handle);
     handle->tty.rd.read_line_handle = NULL;
   }

test/test-list.h

@@ -43,6 +43,9 @@ TEST_DECLARE   (semaphore_1)
 TEST_DECLARE   (semaphore_2)
 TEST_DECLARE   (semaphore_3)
 TEST_DECLARE   (tty)
+#ifdef _WIN32
+TEST_DECLARE   (tty_raw)
+#endif
 TEST_DECLARE   (tty_file)
 TEST_DECLARE   (tty_pty)
 TEST_DECLARE   (stdio_over_pipes)
@@ -387,6 +390,9 @@ TASK_LIST_START
 #endif
   TEST_ENTRY  (pipe_set_non_blocking)
   TEST_ENTRY  (tty)
+#ifdef _WIN32
+  TEST_ENTRY  (tty_raw)
+#endif
   TEST_ENTRY  (tty_file)
   TEST_ENTRY  (tty_pty)
   TEST_ENTRY  (stdio_over_pipes)

test/test-tty.c

@@ -146,6 +146,75 @@ TEST_IMPL(tty) {
 }
 
 
+#ifdef _WIN32
+static void tty_raw_alloc(uv_handle_t* handle, size_t size, uv_buf_t* buf) {
+  buf->base = malloc(size);
+  buf->len = size;
+}
+
+static void tty_raw_read(uv_stream_t* tty_in, ssize_t nread, const uv_buf_t* buf) {
+  if (nread > 0) {
+    ASSERT(nread  == 1);
+    ASSERT(buf->base[0] == ' ');
+    uv_close((uv_handle_t*) tty_in, NULL);
+  } else {
+    ASSERT(nread == 0);
+  }
+}
+
+TEST_IMPL(tty_raw) {
+  int r;
+  int ttyin_fd;
+  uv_tty_t tty_in;
+  uv_loop_t* loop = uv_default_loop();
+  HANDLE handle;
+  INPUT_RECORD record;
+  DWORD written;
+
+  /* Make sure we have an FD that refers to a tty */
+  handle = CreateFileA("conin$",
+                       GENERIC_READ | GENERIC_WRITE,
+                       FILE_SHARE_READ | FILE_SHARE_WRITE,
+                       NULL,
+                       OPEN_EXISTING,
+                       FILE_ATTRIBUTE_NORMAL,
+                       NULL);
+  ASSERT(handle != INVALID_HANDLE_VALUE);
+  ttyin_fd = _open_osfhandle((intptr_t) handle, 0);
+  ASSERT(ttyin_fd >= 0);
+  ASSERT(UV_TTY == uv_guess_handle(ttyin_fd));
+
+  r = uv_tty_init(uv_default_loop(), &tty_in, ttyin_fd, 1);  /* Readable. */
+  ASSERT(r == 0);
+
+  r = uv_read_start((uv_stream_t*)&tty_in, tty_raw_alloc, tty_raw_read);
+  ASSERT(r == 0);
+
+  /* Give uv_tty_line_read_thread time to block on ReadConsoleW */
+  Sleep(100);
+
+  /* Turn on raw mode. */
+  r = uv_tty_set_mode(&tty_in, UV_TTY_MODE_RAW);
+  ASSERT(r == 0);
+
+  /* Write ' ' that should be read in raw mode */
+  record.EventType = KEY_EVENT;
+  record.Event.KeyEvent.bKeyDown = TRUE;
+  record.Event.KeyEvent.wRepeatCount = 1;
+  record.Event.KeyEvent.wVirtualKeyCode = VK_SPACE;
+  record.Event.KeyEvent.wVirtualScanCode = MapVirtualKeyW(VK_SPACE, MAPVK_VK_TO_VSC);
+  record.Event.KeyEvent.uChar.UnicodeChar = L' ';
+  record.Event.KeyEvent.dwControlKeyState = 0;
+  WriteConsoleInputW(handle, &record, 1, &written);
+
+  uv_run(loop, UV_RUN_DEFAULT);
+
+  MAKE_VALGRIND_HAPPY();
+  return 0;
+}
+#endif
+
+
 TEST_IMPL(tty_file) {
 #ifndef _WIN32
   uv_loop_t loop;

uv.gyp

@@ -112,6 +112,7 @@
               '-liphlpapi',
               '-lpsapi',
               '-lshell32',
+              '-luser32',
               '-luserenv',
               '-lws2_32'
             ],