tests: Clean up wait for event

We still use hacks like qmp("") to wait for an event, even though we
have qmp_eventwait() since commit 8fe941f, and qmp_eventwait_ref()
since commit 7ffe312.  Both commits neglected to convert all the
existing hacks.  Make up what they missed.

Bonus: gets rid of empty format strings.  A step towards compile-time
format string checking without triggering -Wformat-zero-length.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
[thuth: dropped the hunks from the usb tests - not needed anymore]
Signed-off-by: Thomas Huth <thuth@redhat.com>

tests/boot-order-test.c

@@ -41,7 +41,7 @@ static void test_a_boot_order(const char *machine,
      * system_reset only requests reset.  We get a RESET event after
      * the actual reset completes.  Need to wait for that.
      */
-    qmp_discard_response("");   /* HACK: wait for event */
+    qmp_eventwait("RESET");
     actual = read_boot_order();
     g_assert_cmphex(actual, ==, expected_reboot);
     qtest_quit(global_qtest);

tests/libqos/pci-pc.c

@@ -173,9 +173,5 @@ void qpci_unplug_acpi_device_test(const char *id, uint8_t slot)
 
     outb(ACPI_PCIHP_ADDR + PCI_EJ_BASE, 1 << slot);
 
-    response = qmp("");
+    qmp_eventwait("DEVICE_DELETED");
-    g_assert(response);
-    g_assert(qdict_haskey(response, "event"));
-    g_assert(!strcmp(qdict_get_str(response, "event"), "DEVICE_DELETED"));
-    QDECREF(response);
 }

tests/tco-test.c

@@ -237,9 +237,8 @@ static void test_tco_max_timeout(void)
 
 static QDict *get_watchdog_action(void)
 {
-    QDict *ev = qmp("");
+    QDict *ev = qmp_eventwait_ref("WATCHDOG");
     QDict *data;
-    g_assert(!strcmp(qdict_get_str(ev, "event"), "WATCHDOG"));
 
     data = qdict_get_qdict(ev, "data");
     QINCREF(data);

tests/wdt_ib700-test.c

@@ -19,26 +19,10 @@ static void qmp_check_no_event(void)
     QDECREF(resp);
 }
 
-static QDict *qmp_get_event(const char *name)
-{
-    QDict *event = qmp("");
-    QDict *data;
-    g_assert(qdict_haskey(event, "event"));
-    g_assert(!strcmp(qdict_get_str(event, "event"), name));
-
-    if (qdict_haskey(event, "data")) {
-        data = qdict_get_qdict(event, "data");
-        QINCREF(data);
-    } else {
-        data = NULL;
-    }
-
-    QDECREF(event);
-    return data;
-}
-
 static QDict *ib700_program_and_wait(QTestState *s)
 {
+    QDict *event, *data;
+
     clock_step(NANOSECONDS_PER_SECOND * 40);
     qmp_check_no_event();
 
@@ -62,7 +46,11 @@ static QDict *ib700_program_and_wait(QTestState *s)
     clock_step(3 * NANOSECONDS_PER_SECOND);
     qmp_check_no_event();
     clock_step(2 * NANOSECONDS_PER_SECOND);
-    return qmp_get_event("WATCHDOG");
+    event = qmp_eventwait_ref("WATCHDOG");
+    data = qdict_get_qdict(event, "data");
+    QINCREF(data);
+    QDECREF(event);
+    return data;
 }
 
 
@@ -74,8 +62,7 @@ static void ib700_pause(void)
     d = ib700_program_and_wait(s);
     g_assert(!strcmp(qdict_get_str(d, "action"), "pause"));
     QDECREF(d);
-    d = qmp_get_event("STOP");
+    qmp_eventwait("STOP");
-    QDECREF(d);
     qtest_end();
 }
 
@@ -87,8 +74,7 @@ static void ib700_reset(void)
     d = ib700_program_and_wait(s);
     g_assert(!strcmp(qdict_get_str(d, "action"), "reset"));
     QDECREF(d);
-    d = qmp_get_event("RESET");
+    qmp_eventwait("RESET");
-    QDECREF(d);
     qtest_end();
 }
 
@@ -100,8 +86,7 @@ static void ib700_shutdown(void)
     d = ib700_program_and_wait(s);
     g_assert(!strcmp(qdict_get_str(d, "action"), "reset"));
     QDECREF(d);
-    d = qmp_get_event("SHUTDOWN");
+    qmp_eventwait("SHUTDOWN");
-    QDECREF(d);
     qtest_end();
 }