Darwin: Fix #108 crash when a device is unplugged

1 files changed, 12 insertions, 2 deletions

diff --git a/libusb/os/darwin_usb.c b/libusb/os/darwin_usb.c
index 169fa1a..9691827 100644
--- a/libusb/os/darwin_usb.c
+++ b/libusb/os/darwin_usb.c
@@ -222,6 +222,7 @@ static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
 
   io_service_t device;
   long location;
+  bool locationValid;
   CFTypeRef locationCF;
   UInt32 message;
 
@@ -231,10 +232,19 @@ static void darwin_devices_detached (void *ptr, io_iterator_t rem_devices) {
     /* get the location from the i/o registry */
     locationCF = IORegistryEntryCreateCFProperty (device, CFSTR(kUSBDevicePropertyLocationID), kCFAllocatorDefault, 0);
 
-    CFNumberGetValue(locationCF, kCFNumberLongType, &location);
-    CFRelease (locationCF);
     IOObjectRelease (device);
 
+    if (!locationCF)
+      continue;
+
+    locationValid = CFGetTypeID(locationCF) == CFNumberGetTypeID() &&
+	    CFNumberGetValue(locationCF, kCFNumberLongType, &location);
+
+    CFRelease (locationCF);
+
+    if (!locationValid)
+      continue;
+
     usbi_mutex_lock(&ctx->open_devs_lock);
     list_for_each_entry(handle, &ctx->open_devs, list, struct libusb_device_handle) {
       dpriv = (struct darwin_device_priv *)handle->dev->os_priv;