source/blender/blenkernel/BKE_nla.h

@@ -41,10 +41,10 @@ struct PropertyRNA;
  */
 void BKE_nlastrip_free(struct NlaStrip *strip, bool do_id_user);
 /**
- * Remove the given NLA track from the set of NLA tracks, free the track's data,
- * and the track itself.
+ * Remove & Frees all NLA strips from the given NLA track,
+ * then frees (doesn't remove) the track itself.
  */
-void BKE_nlatrack_free(ListBase *tracks, struct NlaTrack *nlt, bool do_id_user);
+void BKE_nlatrack_free(struct NlaTrack *nlt, bool do_id_user);
 /**
  * Free the elements of type NLA Tracks provided in the given list, but do not free
  * the list itself since that is not free-standing
@@ -95,6 +95,17 @@ struct NlaTrack *BKE_nlatrack_add(struct AnimData *adt,
                                   struct NlaTrack *prev,
                                   bool is_liboverride);
 
+/**
+ * Removes the given NLA track from the list of tracks provided.
+ */
+void BKE_nlatrack_remove(ListBase *tracks, struct NlaTrack *nlt);
+
+/**
+ * Remove the given NLA track from the list of NLA tracks, free the track's data,
+ * and the track itself.
+ */
+void BKE_nlatrack_remove_and_free(ListBase *tracks, struct NlaTrack *nlt, bool do_id_user);
+
 /**
  * Create a NLA Strip referencing the given Action.
  */

source/blender/blenkernel/intern/nla.c

@@ -91,7 +91,7 @@ void BKE_nlastrip_free(NlaStrip *strip, const bool do_id_user)
   MEM_freeN(strip);
 }
 
-void BKE_nlatrack_free(ListBase *tracks, NlaTrack *nlt, bool do_id_user)
+void BKE_nlatrack_free(NlaTrack *nlt, const bool do_id_user)
 {
   NlaStrip *strip, *stripn;
 
@@ -107,12 +107,7 @@ void BKE_nlatrack_free(ListBase *tracks, NlaTrack *nlt, bool do_id_user)
   }
 
   /* free NLA track itself now */
-  if (tracks) {
-    BLI_freelinkN(tracks, nlt);
-  }
-  else {
-    MEM_freeN(nlt);
-  }
+  MEM_freeN(nlt);
 }
 
 void BKE_nla_tracks_free(ListBase *tracks, bool do_id_user)
@@ -127,7 +122,7 @@ void BKE_nla_tracks_free(ListBase *tracks, bool do_id_user)
   /* free tracks one by one */
   for (nlt = tracks->first; nlt; nlt = nltn) {
     nltn = nlt->next;
-    BKE_nlatrack_free(tracks, nlt, do_id_user);
+    BKE_nlatrack_remove_and_free(tracks, nlt, do_id_user);
   }
 
   /* clear the list's pointers to be safe */
@@ -514,6 +509,20 @@ void BKE_nla_strip_foreach_id(NlaStrip *strip, LibraryForeachIDData *data)
   }
 }
 
+/* Removing ------------------------------------------ */
+
+void BKE_nlatrack_remove(ListBase *tracks, struct NlaTrack *nlt)
+{
+  BLI_assert(tracks);
+  BLI_remlink(tracks, nlt);
+}
+
+void BKE_nlatrack_remove_and_free(ListBase *tracks, struct NlaTrack *nlt, bool do_id_user)
+{
+  BKE_nlatrack_remove(tracks, nlt);
+  BKE_nlatrack_free(nlt, do_id_user);
+}
+
 /* *************************************************** */
 /* NLA Evaluation <-> Editing Stuff */
 

source/blender/blenkernel/intern/nla_test.cc

@@ -91,4 +91,24 @@ TEST(nla_track, BKE_nlatrack_remove_strip)
   EXPECT_EQ(-1, BLI_findindex(&track.strips, &strip2));
 }
 
+TEST(nla_track, BKE_nlatrack_remove_and_free)
+{
+  AnimData adt{}; 
+  NlaTrack *track1;
+  NlaTrack *track2;
+
+  // Add NLA tracks to the Animation Data.
+  track1 = BKE_nlatrack_add(&adt, NULL, false);
+  track2 = BKE_nlatrack_add(&adt, track1, false);
+
+  // ensure we have 2 tracks in the track.
+  EXPECT_EQ(2, BLI_listbase_count(&adt.nla_tracks));
+
+  BKE_nlatrack_remove_and_free(&adt.nla_tracks, track2, false);
+  EXPECT_EQ(1, BLI_listbase_count(&adt.nla_tracks));
+
+  // ensure the correct track was removed.
+  EXPECT_EQ(-1, BLI_findindex(&adt.nla_tracks, track2));
+}
+
 }  // namespace blender::bke::tests

source/blender/editors/space_action/action_data.c

@@ -590,7 +590,7 @@ void ED_animedit_unlink_action(
 
               if (nlt->strips.first == NULL) {
                 BLI_assert(nstrip == NULL);
-                BKE_nlatrack_free(&adt->nla_tracks, nlt, true);
+                BKE_nlatrack_remove_and_free(&adt->nla_tracks, nlt, true);
               }
             }
           }

source/blender/editors/space_nla/nla_channels.c

@@ -736,7 +736,7 @@ static int nlaedit_delete_tracks_exec(bContext *C, wmOperator *UNUSED(op))
       }
 
       /* call delete on this track - deletes all strips too */
-      BKE_nlatrack_free(&adt->nla_tracks, nlt, true);
+      BKE_nlatrack_remove_and_free(&adt->nla_tracks, nlt, true);
       ale->update = ANIM_UPDATE_DEPS;
     }
   }

source/blender/makesrna/intern/rna_animation.c

@@ -593,7 +593,7 @@ static void rna_NlaTrack_remove(
     return;
   }
 
-  BKE_nlatrack_free(&adt->nla_tracks, track, true);
+  BKE_nlatrack_remove_and_free(&adt->nla_tracks, track, true);
   RNA_POINTER_INVALIDATE(track_ptr);
 
   WM_event_add_notifier(C, NC_ANIMATION | ND_NLA | NA_REMOVED, NULL);