[PATCH] a2dp: Fix crash when SEP codec has not been initialized

["Frédéric Danis" <frederic.danis@collabora.com>]

If SEP has not been properly discovered avdtp_get_codec may return NULL
thus causing crashes such as when running AVRCP/TG/VLH/BI-01-C after
AVRCP/TG/RCR/BV-04-C
---
 profiles/audio/a2dp.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/profiles/audio/a2dp.c b/profiles/audio/a2dp.c
index f761dbe54..7da008071 100644
--- a/profiles/audio/a2dp.c
+++ b/profiles/audio/a2dp.c
@@ -1995,7 +1995,12 @@ static gboolean get_codec(const GDBusPropertyTable *property,
 {
 	struct a2dp_remote_sep *sep = data;
 	struct avdtp_service_capability *cap = avdtp_get_codec(sep->sep);
-	struct avdtp_media_codec_capability *codec = (void *) cap->data;
+	struct avdtp_media_codec_capability *codec;
+
+	if (!cap)
+		return FALSE;
+
+	codec = (void *) cap->data;
 
 	dbus_message_iter_append_basic(iter, DBUS_TYPE_BYTE,
 						&codec->media_codec_type);
@@ -2008,10 +2013,16 @@ static gboolean get_capabilities(const GDBusPropertyTable *property,
 {
 	struct a2dp_remote_sep *sep = data;
 	struct avdtp_service_capability *service = avdtp_get_codec(sep->sep);
-	struct avdtp_media_codec_capability *codec = (void *) service->data;
-	uint8_t *caps = codec->data;
+	struct avdtp_media_codec_capability *codec;
+	uint8_t *caps;
 	DBusMessageIter array;
 
+	if (!service)
+		return FALSE;
+
+	codec = (void *) service->data;
+	caps = codec->data;
+
 	dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
 					DBUS_TYPE_BYTE_AS_STRING, &array);
 
-- 
2.25.1