Fix potential crash opening 3.0 blend files in older versions.

Affects insertion of constraints or NLA tracks in liboverrides. In some
cases, when opening newer post-3.0 .blend files, the source won't be
found anymore, override apply code then needs to fail properly instead
of crashing.

Related to refactor from  rB33c5e7bcd5e5.

2 files changed, 8 insertions, 2 deletions

diff --git a/source/blender/makesrna/intern/rna_animation.c b/source/blender/makesrna/intern/rna_animation.c
index 10f86fe2671..d3580b901c0 100644
--- a/source/blender/makesrna/intern/rna_animation.c
+++ b/source/blender/makesrna/intern/rna_animation.c
@@ -775,7 +775,10 @@ bool rna_NLA_tracks_override_apply(Main *bmain,
   }
   nla_track_src = nla_track_src ? nla_track_src->next : anim_data_src->nla_tracks.first;
 
-  BLI_assert(nla_track_src != NULL);
+  if (nla_track_src == NULL) {
+    BLI_assert(nla_track_src != NULL);
+    return false;
+  }
 
   NlaTrack *nla_track_dst = BKE_nlatrack_copy(bmain, nla_track_src, true, 0);
 
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 6b93a1c223c..481d4c1c7e9 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -1601,7 +1601,10 @@ bool rna_Object_constraints_override_apply(Main *UNUSED(bmain),
   }
   con_src = con_src ? con_src->next : ob_src->constraints.first;
 
-  BLI_assert(con_src != NULL);
+  if (con_src == NULL) {
+    BLI_assert(con_src != NULL);
+    return false;
+  }
 
   bConstraint *con_dst = BKE_constraint_duplicate_ex(con_src, 0, true);