[PATCH 6/7] tests/qtest: tighten up the checks on clock_step

[Alex Bennée]

It is invalid to call clock_step with an implied time to step forward
as if no timers are running we won't be able to advance.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 system/qtest.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/system/qtest.c b/system/qtest.c
index 28b6fac37c..1a9bfd0b33 100644
--- a/system/qtest.c
+++ b/system/qtest.c
@@ -708,10 +708,15 @@ static void qtest_process_command(CharBackend *chr, gchar 
**words)
         } else {
             ns = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL,
                                             QEMU_TIMER_ATTR_ALL);
+            if (ns < 0) {
+                qtest_send(chr, "FAIL "
+                           "no timers for clock_step to follow\n");
+                return;
+            }
         }
         new_ns = qemu_clock_advance_virtual_time(old_ns + ns);
         qtest_sendf(chr, "%s %"PRIi64"\n",
-                    new_ns > old_ns ? "OK" : "FAIL", new_ns);
+                    new_ns > old_ns ? "OK" : "FAIL could not advance time", 
new_ns);
     } else if (strcmp(words[0], "module_load") == 0) {
         Error *local_err = NULL;
         int rv;
-- 
2.39.5