Fix: Don't save an empty <contexts> node in kernel channels

An empty <contexts/> node is saved when kernel channels are
saved even when no kernel contexts are enabled.

Note that this is a minor fix as the generated XML remains valid
anyhow.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/src/bin/lttng-sessiond/save.c b/src/bin/lttng-sessiond/save.c
index d268f33190698d6f9bd920a5bbdbab140a377d70..908e5f8fd2924d67223ffbdcbf8a04dfc158a502 100644 (file)
--- a/src/bin/lttng-sessiond/save.c
+++ b/src/bin/lttng-sessiond/save.c
@@ -801,6 +801,11 @@ int save_kernel_contexts(struct config_writer *writer,
        int ret;
        struct ltt_kernel_context *ctx;
 
+       if (cds_list_empty(&kchan->ctx_list)) {
+               ret = 0;
+               goto end;
+       }
+
        ret = config_writer_open_element(writer, config_element_contexts);
        if (ret) {
                ret = LTTNG_ERR_SAVE_IO_FAIL;