Avoid NULL dereference in JACK backend on startup failure

Without this, there is a segmentation fault when the initialization of Jalv
fails and it exits before the backend was initialized.

1 files changed, 8 insertions, 4 deletions

diff --git a/src/jack.c b/src/jack.c
index 7c9f387..337b3dd 100644
--- a/src/jack.c
+++ b/src/jack.c
@@ -388,9 +388,11 @@ jalv_backend_init(Jalv* jalv)
 void
 jalv_backend_close(Jalv* jalv)
 {
-	jack_client_close(jalv->backend->client);
-	free(jalv->backend);
-	jalv->backend = NULL;
+	if (!jalv->backend) {
+		jack_client_close(jalv->backend->client);
+		free(jalv->backend);
+		jalv->backend = NULL;
+	}
 }
 
 void
@@ -402,7 +404,9 @@ jalv_backend_activate(Jalv* jalv)
 void
 jalv_backend_deactivate(Jalv* jalv)
 {
-	jack_deactivate(jalv->backend->client);
+	if (jalv->backend) {
+		jack_deactivate(jalv->backend->client);
+	}
 }
 
 void