[Qemu-devel] [PATCH v5 5/5] qobject: modify qobject_ref() to assert on NULL

[Marc-André Lureau]

While it may be convenient to accept NULL value in
qobject_unref() (for similar reasons as free() accepts NULL), it is
not such a good idea for qobject_ref(), assert() on NULL. One place
relied on that behaviour (the monitor request id), and it's best to be
explicit that NULL is accepted there.

Signed-off-by: Marc-André Lureau <address@hidden>
---
 include/qapi/qmp/qobject.h | 7 ++++---
 monitor.c                  | 2 +-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index befc945504..a0b2affb2c 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -73,9 +73,8 @@ static inline void qobject_init(QObject *obj, QType type)
 
 static inline void *qobject_ref_impl(QObject *obj)
 {
-    if (obj) {
-        obj->base.refcnt++;
-    }
+    assert(obj);
+    obj->base.refcnt++;
     return obj;
 }
 
@@ -103,6 +102,7 @@ static inline void qobject_unref_impl(QObject *obj)
 
 /**
  * qobject_ref(): Increment QObject's reference count
+ * @obj: a #QObject or child type instance (must not be NULL)
  *
  * Returns: the same @obj. The type of @obj will be propagated to the
  * return type.
@@ -112,6 +112,7 @@ static inline void qobject_unref_impl(QObject *obj)
 /**
  * qobject_unref(): Decrement QObject's reference count, deallocate
  * when it reaches zero
+ * @obj: a #QObject or children type instance (can be NULL)
  */
 #define qobject_unref(obj) qobject_unref_impl(QOBJECT(obj))
 
diff --git a/monitor.c b/monitor.c
index 7dbc1f74b8..3a750208fd 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4188,7 +4188,7 @@ static void handle_qmp_command(JSONMessageParser *parser, 
GQueue *tokens)
 
     req_obj = g_new0(QMPRequest, 1);
     req_obj->mon = mon;
-    req_obj->id = qobject_ref(id);
+    req_obj->id = id ? qobject_ref(id) : NULL;
     req_obj->req = req;
     req_obj->need_resume = false;
 
-- 
2.17.0.rc1.36.gcedb63ea2f