make msc_a_vsub() and others NULL-safe

Fixes: coverity CID 198451
Change-Id: Icd146ae512236a09cad080ed3eb85944e8f5cee4

3 files changed, 10 insertions, 0 deletions

diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c
index 675f93202..5baed5458 100644
--- a/src/libmsc/msc_a.c
+++ b/src/libmsc/msc_a.c
@@ -73,16 +73,22 @@ struct gsm_network *msc_a_net(const struct msc_a *msc_a)
 
 struct vlr_subscr *msc_a_vsub(const struct msc_a *msc_a)
 {
+	if (!msc_a)
+		return NULL;
 	return msub_vsub(msc_a->c.msub);
 }
 
 struct msc_i *msc_a_msc_i(const struct msc_a *msc_a)
 {
+	if (!msc_a)
+		return NULL;
 	return msub_msc_i(msc_a->c.msub);
 }
 
 struct msc_t *msc_a_msc_t(const struct msc_a *msc_a)
 {
+	if (!msc_a)
+		return NULL;
 	return msub_msc_t(msc_a->c.msub);
 }
 
diff --git a/src/libmsc/msc_i.c b/src/libmsc/msc_i.c
index 6badba668..05df9cb5d 100644
--- a/src/libmsc/msc_i.c
+++ b/src/libmsc/msc_i.c
@@ -332,6 +332,8 @@ struct gsm_network *msc_i_net(const struct msc_i *msc_i)
 
 struct vlr_subscr *msc_i_vsub(const struct msc_i *msc_i)
 {
+	if (!msc_i)
+		return NULL;
 	return msub_vsub(msc_i->c.msub);
 }
 
diff --git a/src/libmsc/msc_t.c b/src/libmsc/msc_t.c
index ec5531fc2..c6bba471f 100644
--- a/src/libmsc/msc_t.c
+++ b/src/libmsc/msc_t.c
@@ -902,6 +902,8 @@ struct gsm_network *msc_t_net(const struct msc_t *msc_t)
 
 struct vlr_subscr *msc_t_vsub(const struct msc_t *msc_t)
 {
+	if (!msc_t)
+		return NULL;
 	return msub_vsub(msc_t->c.msub);
 }