[PATCH xserver] config: fix NULL value detection for ID_INPUT being unset

[Peter Hutterer]

Erroneous condition caused us to keep going with all devices that didn't have
ID_INPUT set.

Introduced in 5aad81445c8c3d6

https://bugs.freedesktop.org/show_bug.cgi?id=104382

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 config/udev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config/udev.c b/config/udev.c
index e198e8609..3a73189e2 100644
--- a/config/udev.c
+++ b/config/udev.c
@@ -135,7 +135,7 @@ device_added(struct udev_device *udev_device)
 #endif
 
     value = udev_device_get_property_value(udev_device, "ID_INPUT");
-    if (value && !strcmp(value, "0")) {
+    if (!value || !strcmp(value, "0")) {
         LogMessageVerb(X_INFO, 10,
                        "config/udev: ignoring device %s without "
                        "property ID_INPUT set\n", path);
-- 
2.13.6