@@ -442,14 +442,20 @@ void qmp_fd_sendv(int fd, const char *fmt, va_list ap)
if (qobj) {
int log = getenv("QTEST_LOG") != NULL;
QString *qstr = qobject_to_json(qobj);
- const char *str = qstring_get_str(qstr);
- size_t size = qstring_get_length(qstr);
+ const char *str;
+
+ /*
+ * BUG: QMP doesn't react to input until it sees a newline, an
+ * object, or an array. Work-around: give it a newline.
+ */
+ qstring_append_chr(qstr, '\n');
+ str = qstring_get_str(qstr);
if (log) {
fprintf(stderr, "%s", str);
}
/* Send QMP request */
- socket_send(fd, str, size);
+ socket_send(fd, str, qstring_get_length(qstr));
QDECREF(qstr);
qobject_decref(qobj);
The next commit is going to add a test that calls qmp("null"). Curiously, this hangs. Here's why. qmp_fd_sendv() doesn't send newlines. Not even when @fmt contains some. At first glance, the QMP parser seems to be fine with that. However, it turns out that it fails to react to input until it sees either a newline, an object or an array. To reproduce, feed to a QMP monitor like this: $ echo -n 'null' | socat UNIX:/work/armbru/images/test-qmp STDIO {"QMP": {"version": {"qemu": {"micro": 50, "minor": 8, "major": 2}, "package": " (v2.8.0-1195-gf84141e-dirty)"}, "capabilities": []}} No output after the greeting. Add a newline: $ echo 'null' | socat UNIX:/work/armbru/images/test-qmp STDIO {"QMP": {"version": {"qemu": {"micro": 50, "minor": 8, "major": 2}, "package": " (v2.8.0-1195-gf84141e-dirty)"}, "capabilities": []}} {"error": {"class": "GenericError", "desc": "Expected 'object' in QMP input"}} Correct output for input 'null'. Add an object instead: $ echo -n 'null { "execute": "qmp_capabilities" }' | socat UNIX:qmp-socket STDIO {"QMP": {"version": {"qemu": {"micro": 50, "minor": 8, "major": 2}, "package": " (v2.8.0-1195-gf84141e-dirty)"}, "capabilities": []}} {"error": {"class": "GenericError", "desc": "Expected 'object' in QMP input"}} {"return": {}} Also correct output. Work around this QMP bug by having qmp_fd_sendv() append a newline. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <1488303560-18803-3-git-send-email-armbru@redhat.com> --- tests/libqtest.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)