hw: Don't call visit_end_struct() after visit_start_struct() fails

When visit_start_struct() fails, visit_end_struct() must not be
called.  rtc_get_date() and balloon_stats_all() call it anyway.  As
far as I can tell, they're only used with the string output visitor,
which doesn't care.  Fix them anyway.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 15 insertions, 8 deletions

diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 8509309..6c3e3b6 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -793,19 +793,26 @@ static const MemoryRegionOps cmos_ops = {
 static void rtc_get_date(Object *obj, Visitor *v, void *opaque,
                          const char *name, Error **errp)
 {
+    Error *err = NULL;
     RTCState *s = MC146818_RTC(obj);
     struct tm current_tm;
 
     rtc_update_time(s);
     rtc_get_time(s, &current_tm);
-    visit_start_struct(v, NULL, "struct tm", name, 0, errp);
-    visit_type_int32(v, &current_tm.tm_year, "tm_year", errp);
-    visit_type_int32(v, &current_tm.tm_mon, "tm_mon", errp);
-    visit_type_int32(v, &current_tm.tm_mday, "tm_mday", errp);
-    visit_type_int32(v, &current_tm.tm_hour, "tm_hour", errp);
-    visit_type_int32(v, &current_tm.tm_min, "tm_min", errp);
-    visit_type_int32(v, &current_tm.tm_sec, "tm_sec", errp);
-    visit_end_struct(v, errp);
+    visit_start_struct(v, NULL, "struct tm", name, 0, &err);
+    if (err) {
+        goto out;
+    }
+    visit_type_int32(v, &current_tm.tm_year, "tm_year", &err);
+    visit_type_int32(v, &current_tm.tm_mon, "tm_mon", &err);
+    visit_type_int32(v, &current_tm.tm_mday, "tm_mday", &err);
+    visit_type_int32(v, &current_tm.tm_hour, "tm_hour", &err);
+    visit_type_int32(v, &current_tm.tm_min, "tm_min", &err);
+    visit_type_int32(v, &current_tm.tm_sec, "tm_sec", &err);
+    visit_end_struct(v, &err);
+
+out:
+    error_propagate(errp, err);
 }
 
 static void rtc_realizefn(DeviceState *dev, Error **errp)