Merge win32unix/dup2.c into win32unix/dup.c and factor code

otherlibs/win32unix/Makefile

@@ -19,7 +19,7 @@
 
 # Files in this directory
 WIN_FILES = accept.c bind.c channels.c close.c \
-  close_on.c connect.c createprocess.c dup.c dup2.c errmsg.c envir.c \
+  close_on.c connect.c createprocess.c dup.c errmsg.c envir.c \
   getpeername.c getpid.c getsockname.c gettimeofday.c isatty.c \
   link.c listen.c lockf.c lseek.c nonblock.c \
   mmap.c open.c pipe.c read.c readlink.c rename.c \

otherlibs/win32unix/dup.c

@@ -21,47 +21,97 @@
 #define _WIN32_LEAN_AND_MEAN
 #include <winsock2.h>
 
+static HANDLE duplicate_handle(BOOL cloexec, HANDLE oldh)
+{
+  HANDLE newh;
+  HANDLE proc = GetCurrentProcess();
+  if (! DuplicateHandle(proc, oldh, proc, &newh,
+                        0L,
+                        cloexec,
+                        DUPLICATE_SAME_ACCESS)) {
+    win32_maperr(GetLastError());
+    return INVALID_HANDLE_VALUE;
+  }
+  return newh;
+}
+
+static SOCKET duplicate_socket(SOCKET oldsock)
+{
+  WSAPROTOCOL_INFO info;
+  SOCKET newsock;
+  if (SOCKET_ERROR == WSADuplicateSocket(oldsock,
+                                         GetCurrentProcessId(),
+                                         &info)) {
+    win32_maperr(WSAGetLastError());
+    return INVALID_SOCKET;
+  }
+
+  newsock = WSASocket(info.iAddressFamily, info.iSocketType, info.iProtocol,
+                      &info, 0, WSA_FLAG_OVERLAPPED);
+  if (INVALID_SOCKET == newsock)
+    win32_maperr(WSAGetLastError());
+  return newsock;
+}
+
 CAMLprim value unix_dup(value cloexec, value fd)
 {
   CAMLparam2(cloexec, fd);
   CAMLlocal1(newfd);
 
   switch (Descr_kind_val(fd)) {
   case KIND_HANDLE: {
-    HANDLE newh;
-    if (! DuplicateHandle(GetCurrentProcess(), Handle_val(fd),
-                          GetCurrentProcess(), &newh,
-                          0L,
-                          unix_cloexec_p(cloexec) ? FALSE : TRUE,
-                          DUPLICATE_SAME_ACCESS)) {
-      win32_maperr(GetLastError());
+    HANDLE newh = duplicate_handle(unix_cloexec_p(cloexec) ? FALSE : TRUE,
+                                   Handle_val(fd));
+    if (newh == INVALID_HANDLE_VALUE)
       uerror("dup", Nothing);
-    }
     newfd = win_alloc_handle(newh);
     CAMLreturn(newfd);
   }
   case KIND_SOCKET: {
-    WSAPROTOCOL_INFO info;
-    SOCKET newsock;
-
-    if (SOCKET_ERROR == WSADuplicateSocket(Socket_val(fd),
-                                           GetCurrentProcessId(),
-                                           &info)) {
-      win32_maperr(WSAGetLastError());
+    SOCKET newsock = duplicate_socket(Socket_val(fd));
+    if (newsock == INVALID_SOCKET)
       uerror("dup", Nothing);
-    }
-
-    newsock = WSASocket(info.iAddressFamily, info.iSocketType, info.iProtocol,
-                        &info, 0, WSA_FLAG_OVERLAPPED);
-    if (INVALID_SOCKET == newsock) {
-      win32_maperr(WSAGetLastError());
-      uerror("dup", Nothing);
-    }
-
     newfd = win_alloc_socket(newsock);
     CAMLreturn(newfd);
   }
   default:
     caml_invalid_argument("Invalid file descriptor type");
   }
 }
+
+CAMLprim value unix_dup2(value cloexec, value fd1, value fd2)
+{
+  CAMLparam3(cloexec, fd1, fd2);
+
+  if (Descr_kind_val(fd1) != Descr_kind_val(fd2))
+    caml_invalid_argument("Expected either two file handles or two sockets");
+
+  switch (Descr_kind_val(fd1)) {
+  case KIND_HANDLE: {
+    HANDLE oldh = Handle_val(fd2),
+      newh = duplicate_handle(unix_cloexec_p(cloexec) ? FALSE : TRUE,
+                              Handle_val(fd1));
+    if (newh == INVALID_HANDLE_VALUE)
+      uerror("dup2", Nothing);
+    Handle_val(fd2) = newh;
+    CloseHandle(oldh);
+    break;
+  }
+  case KIND_SOCKET: {
+    SOCKET oldsock = Socket_val(fd2),
+      newsock = duplicate_socket(Socket_val(fd1));
+    if (newsock == INVALID_SOCKET)
+      uerror("dup2", Nothing);
+    Socket_val(fd2) = newsock;
+    closesocket(oldsock);
+    break;
+  }
+  default:
+    caml_invalid_argument("Invalid file descriptor type");
+  }
+
+  /* Reflect the dup2 on the CRT fds, if any */
+  if (CRT_fd_val(fd1) != NO_CRT_FD || CRT_fd_val(fd2) != NO_CRT_FD)
+    _dup2(win_CRT_fd_of_filedescr(fd1), win_CRT_fd_of_filedescr(fd2));
+  CAMLreturn(Val_unit);
+}