use _close() rather than CloseHandle() in usbi_close()

* use of CloseHandle() prevented the pipe fds from being
  relinquished on libusb_exit()
* leaked fds could lead to the OS running out of new fds
  and LIBUSB_ERROR_NO_MEM being returned as a result
* issue reported by Stephano Antonelli

2 files changed, 8 insertions, 8 deletions

diff --git a/libusb/os/poll_windows.c b/libusb/os/poll_windows.c
index 3657be5..f7ca6ea 100644
--- a/libusb/os/poll_windows.c
+++ b/libusb/os/poll_windows.c
@@ -401,7 +401,8 @@ struct winfd usbi_create_fd(HANDLE handle, int access_mode)
 		wfd.rw = RW_WRITE;
 	}
 
-	// Ensure that we get a non system conflicting unique fd
+	// Ensure that we get a non system conflicting unique fd, using
+	// the same fd attribution system as the pipe ends
 	fd = _open_osfhandle((intptr_t)CreateFileA("NUL", 0, 0,
 		NULL, OPEN_EXISTING, 0, NULL), _O_RDWR);
 	if (fd < 0) {
@@ -788,10 +789,9 @@ int usbi_close(int fd)
 			CloseHandle(poll_fd[_index].overlapped->hEvent);
 			free(poll_fd[_index].overlapped);
 		}
-		if (CloseHandle(poll_fd[_index].handle) == 0) {
+		r = _close(poll_fd[_index].fd);
+		if (r != 0) {
 			errno = EIO;
-		} else {
-			r = 0;
 		}
 		poll_fd[_index] = INVALID_WINFD;
 		LeaveCriticalSection(&_poll_fd[_index].mutex);
diff --git a/libusb/os/poll_windows.h b/libusb/os/poll_windows.h
index a9e3e90..dfa4650 100644
--- a/libusb/os/poll_windows.h
+++ b/libusb/os/poll_windows.h
@@ -72,10 +72,10 @@ enum rw_type {
 
 // fd struct that can be used for polling on Windows
 struct winfd {
-	int fd;				            // what's exposed to libusb core
-	HANDLE handle;                  // what we need to attach overlapped to the I/O op, so we can poll it
-	OVERLAPPED* overlapped;         // what will report our I/O status
-	enum rw_type rw;                // I/O transfer direction: read *XOR* write (NOT BOTH)
+	int fd;							// what's exposed to libusb core
+	HANDLE handle;					// what we need to attach overlapped to the I/O op, so we can poll it
+	OVERLAPPED* overlapped;			// what will report our I/O status
+	enum rw_type rw;				// I/O transfer direction: read *XOR* write (NOT BOTH)
 };
 extern const struct winfd INVALID_WINFD;