core: reset bus error before reuse

From a report in https://bugzilla.redhat.com/show_bug.cgi?id=1861463:
usb-gadget.target: Failed to load configuration: No such file or directory
usb-gadget.target: Failed to load configuration: No such file or directory
usb-gadget.target: Trying to enqueue job usb-gadget.target/start/fail
usb-gadget.target: Failed to load configuration: No such file or directory
Assertion '!bus_error_is_dirty(e)' failed at src/libsystemd/sd-bus/bus-error.c:239, function bus_error_setfv(). Ignoring.
sys-devices-platform-soc-2100000.bus-2184000.usb-ci_hdrc.0-udc-ci_hdrc.0.device: Failed to enqueue SYSTEMD_WANTS= job, ignoring: Unit usb-gadget.target not found.

I *think* this is the place where the reuse occurs: we call
bus_unit_validate_load_state(unit, e) twice in a row.

diff --git a/src/core/transaction.c b/src/core/transaction.c
index 4a57b8e3f9c32f65db09cff8f8b76f97f260f7d5..958243bc94b14747869c9d7805c6cfc5a8db2cba 100644 (file)
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -966,6 +966,7 @@ int transaction_add_job_and_dependencies(
                  * Given building up the transaction is a synchronous operation, attempt
                  * to load the unit immediately. */
                 if (r < 0 && manager_unit_file_maybe_loadable_from_cache(unit)) {
+                        sd_bus_error_free(e);
                         unit->load_state = UNIT_STUB;
                         r = unit_load(unit);
                         if (r < 0 || unit->load_state == UNIT_STUB)