[PATCH v2 23/30] qapi: Simplify how qmp_dispatch() gets the request ID

[Markus Armbruster <armbru@redhat.com>]

We convert the request object to a QDict twice: first in
qmp_dispatch() to get the request ID, and then again in
qmp_dispatch_check_obj(), which converts to QDict, then checks and
returns it.  We can't get the request ID from the latter, because it's
null when the qdict flunks the checks.

Move getting the request ID into qmp_dispatch_check_obj().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 qapi/qmp-dispatch.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/qapi/qmp-dispatch.c b/qapi/qmp-dispatch.c
index 550d1fe8d2..112d29a9ab 100644
--- a/qapi/qmp-dispatch.c
+++ b/qapi/qmp-dispatch.c
@@ -20,7 +20,7 @@
 #include "qapi/qmp/qbool.h"
 
 static QDict *qmp_dispatch_check_obj(const QObject *request, bool allow_oob,
-                                     Error **errp)
+                                     QObject **id, Error **errp)
 {
     const char *exec_key = NULL;
     const QDictEntry *ent;
@@ -30,10 +30,13 @@ static QDict *qmp_dispatch_check_obj(const QObject *request, bool allow_oob,
 
     dict = qobject_to(QDict, request);
     if (!dict) {
+        *id = NULL;
         error_setg(errp, "QMP input must be a JSON object");
         return NULL;
     }
 
+    *id = qdict_get(dict, "id");
+
     for (ent = qdict_first(dict); ent;
          ent = qdict_next(dict, ent)) {
         arg_name = qdict_entry_key(ent);
@@ -103,12 +106,12 @@ QDict *qmp_dispatch(QmpCommandList *cmds, QObject *request,
     const char *command;
     QDict *args;
     QmpCommand *cmd;
-    QDict *dict = qobject_to(QDict, request);
-    QObject *id = dict ? qdict_get(dict, "id") : NULL;
+    QDict *dict;
+    QObject *id;
     QObject *ret = NULL;
     QDict *rsp = NULL;
 
-    dict = qmp_dispatch_check_obj(request, allow_oob, &err);
+    dict = qmp_dispatch_check_obj(request, allow_oob, &id, &err);
     if (!dict) {
         goto out;
     }
-- 
2.21.1