Emergency fix for Mac: crash with EXC_ARITHMETIC in submit_bulk_transfer

third_party/libusb/src/libusb/os/darwin_usb.c

 /* -*- Mode: C; indent-tabs-mode:nil -*- */
 /*
  * darwin backend for libusbx 1.0
  * Copyright © 2008-2013 Nathan Hjelm <hjelmn@users.sourceforge.net>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
@@ skipping 1430 matching lines @@
   struct darwin_interface *cInterface;
 
   if (ep_to_pipeRef (transfer->dev_handle, transfer->endpoint, &pipeRef, &iface) != 0) {
     usbi_err (TRANSFER_CTX (transfer), "endpoint not found on any open interface");
 
     return LIBUSB_ERROR_NOT_FOUND;
   }
 
   cInterface = &priv->interfaces[iface];
 
-  (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number,
-                                                 &transferType, &maxPacketSize, &interval);
+  ret = (*(cInterface->interface))->GetPipeProperties (cInterface->interface, pipeRef, &direction, &number,

[meacer, 2013/08/23 16:57:27]

GetPipeProperties are called twice more in this file without error checking.
(https://code.google.com/p/chromium/codesearch#chromium/src/third_party/libusb...)

Do you think we need to add checks there as well?

[Bei Zhang, 2013/08/23 17:07:28]

Other calls in this file doesn't seem to cause any problem if left as is.
Though, one of them is redundant. I will say leave them as is for now.

On 2013/08/23 16:57:27, Mustafa Emre Acer wrote:

[meacer, 2013/08/23 17:10:04]

Sounds good, thanks Bei.

+                                                       &transferType, &maxPacketSize, &interval);
+
+  if (ret) {
+    usbi_err (TRANSFER_CTX (transfer), "bulk transfer failed (dir = %s): %s (code = 0x%08x)", IS_XFERIN(transfer) ? "In" : "Out",
+              darwin_error_str(ret), ret);
+    return darwin_to_libusb (ret);
+  }
 
   if (0 != (transfer->length % maxPacketSize)) {
     /* do not need a zero packet */
     transfer->flags &= ~LIBUSB_TRANSFER_ADD_ZERO_PACKET;
   }
 
   /* submit the request */
   /* timeouts are unavailable on interrupt endpoints */
   if (transferType == kUSBInterrupt) {
     if (IS_XFERIN(transfer))
@@ skipping 431 matching lines @@
 
         .handle_events = op_handle_events,
 
         .clock_gettime = darwin_clock_gettime,
 
         .device_priv_size = sizeof(struct darwin_device_priv),
         .device_handle_priv_size = sizeof(struct darwin_device_handle_priv),
         .transfer_priv_size = sizeof(struct darwin_transfer_priv),
         .add_iso_packet_size = 0,
 };