device: Avoid calling unit_free(NULL) in device setup logic (#4748)

Since a581e45ae8f9bb5c, there's a few function calls to
unit_new_for_name which will unit_free on failure. Prior to this commit,
a failure would result in calling unit_free with a NULL unit, and hit an
assertion failure, seen at least via device_setup_unit:

Assertion 'u' failed at src/core/unit.c:519, function unit_free().  Aborting.

Fixes #4747
https://bugs.archlinux.org/task/51950

diff --git a/src/core/device.c b/src/core/device.c
index 074e93ffe2ea0ea7ab4c9bdfb53831430d21cd6b..8e2e3c7bedc299235d077855f4a2f50f761335b4 100644 (file)
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -359,7 +359,7 @@ static int device_setup_unit(Manager *m, struct udev_device *dev, const char *pa
 fail:
         log_unit_warning_errno(u, r, "Failed to set up device unit: %m");
 
-        if (delete)
+        if (delete && u)
                 unit_free(u);
 
         return r;