Emergency fix for Mac: crash with EXC_ARITHMETIC in submit_bulk_transfer

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

Index: third_party/libusb/src/libusb/os/darwin_usb.c
diff --git a/third_party/libusb/src/libusb/os/darwin_usb.c b/third_party/libusb/src/libusb/os/darwin_usb.c
index a24558cb593b4ecdca032a45ddc8fcba7b0faabd..3f315e84be6e16a4c00c4c2f10fd1f27a8f4a13c 100644
--- a/third_party/libusb/src/libusb/os/darwin_usb.c
+++ b/third_party/libusb/src/libusb/os/darwin_usb.c
@@ -1448,8 +1448,14 @@ static int submit_bulk_transfer(struct usbi_transfer *itransfer) {
 
   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 */