macOS: check if IOHIDManagerCopyDevices returned a NULL (#209)

jonasmalacofilho · web-flow · commit ce606fac8f47 · 2020-11-23T21:03:03.000+02:00
Removes a possible cause for a segmentation fault observed in `CFSetGetCount`. Related: #208 ("Segmentation fault on Mac OS Catalina"). Signed-off-by: Jonas Malaco <jonas@protocubo.io>
diff --git a/mac/hid.c b/mac/hid.c
@@ -583,6 +583,9 @@ struct hid_device_info  HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
 	}
 
 	CFSetRef device_set = IOHIDManagerCopyDevices(hid_mgr);
+	if (device_set == NULL) {
+		return NULL;
+	}
 
 	/* Convert the list into a C array so we can iterate easily. */
 	num_devices = CFSetGetCount(device_set);

Original file line number	Diff line number	Diff line change
`@@ -583,6 +583,9 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,`
`583`	`583`	`}`
`584`	`584`
`585`	`585`	`CFSetRef device_set = IOHIDManagerCopyDevices(hid_mgr);`
	`586`	`+ if (device_set == NULL) {`
	`587`	`+ return NULL;`
	`588`	`+ }`
`586`	`589`
`587`	`590`	`/* Convert the list into a C array so we can iterate easily. */`
`588`	`591`	`num_devices = CFSetGetCount(device_set);`