char: Explain qmp_chardev_add()'s unusual error handling
Character backend open hasn't been fully converted to the Error API.
Some opens fail without setting an error. qmp_chardev_add() needs to
detect when that happens, and set a generic error. Explain that in a
comment, and inline error_is_set() for clarity.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/qemu-char.c b/qemu-char.c
index 5a7975f..17b476e 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -3798,7 +3798,13 @@
break;
}
- if (chr == NULL && !error_is_set(errp)) {
+ /*
+ * Character backend open hasn't been fully converted to the Error
+ * API. Some opens fail without setting an error. Set a generic
+ * error then.
+ * TODO full conversion to Error API
+ */
+ if (chr == NULL && errp && !*errp) {
error_setg(errp, "Failed to create chardev");
}
if (chr) {
