[PATCH] qapi: fix memory leak in visit_type_UserDefOneList

[Li Qiang <liq3ea@163.com>]

While executing 'tests/test-qobject-input-visitor'. I got
following error:

/visitor/input/fail/alternate: OK
/visitor/input/fail/union-list: OK

=================================================================
==4353==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x7f192d0c5d28 in __interceptor_calloc (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
    #1 0x7f192cd21b10 in g_malloc0 (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51b10)
    #2 0x556725f6bbee in visit_next_list qapi/qapi-visit-core.c:86
    #3 0x556725f49e15 in visit_type_UserDefOneList tests/test-qapi-visit.c:474
    #4 0x556725f4489b in test_visitor_in_fail_struct_in_list tests/test-qobject-input-visitor.c:1086
    #5 0x7f192cd42f29  (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72f29)

SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).

This is because we don't free the last element of the linkedlist
if 'visit_type_UserDefOne' fails. This patch fixes this.

Fixes: cdd2b228b97("qapi: Smooth visitor error checking in generated
code")

Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Li Qiang <liq3ea@163.com>
---
 scripts/qapi/visit.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
index 3fb2f30510..cdabc5fa28 100644
--- a/scripts/qapi/visit.py
+++ b/scripts/qapi/visit.py
@@ -249,6 +249,7 @@ bool visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj, Error
     if (!*obj) {
         /* incomplete */
         assert(visit_is_dealloc(v));
+        ok = true;
         goto out_obj;
     }
     if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
-- 
2.17.1