Fix T52332: crash when duplicating sequencer strips.

Bug introduced in recent ID copying refactor.

This commit basically sanitizes seq strip copying behavior, by making
destination scene pointer mandatory (and source one a const one).
Nothing then prevents you from using same pointer as source and
destination!

3 files changed, 20 insertions, 16 deletions

diff --git a/source/blender/blenkernel/BKE_sequencer.h b/source/blender/blenkernel/BKE_sequencer.h
index 87d63b7d6f6..f3e3abab87a 100644
--- a/source/blender/blenkernel/BKE_sequencer.h
+++ b/source/blender/blenkernel/BKE_sequencer.h
@@ -335,7 +335,8 @@ bool BKE_sequence_base_shuffle(
 bool BKE_sequence_base_shuffle_time(ListBase *seqbasep, struct Scene *evil_scene);
 bool BKE_sequence_base_isolated_sel_check(struct ListBase *seqbase);
 void BKE_sequencer_free_imbuf(struct Scene *scene, struct ListBase *seqbasep, bool for_render);
-struct Sequence *BKE_sequence_dupli_recursive(struct Scene *scene, struct Scene *scene_to, struct Sequence *seq, int dupe_flag);
+struct Sequence *BKE_sequence_dupli_recursive(
+        const struct Scene *scene, struct Scene *scene_to, struct Sequence *seq, int dupe_flag);
 int BKE_sequence_swap(struct Sequence *seq_a, struct Sequence *seq_b, const char **error_str);
 
 bool BKE_sequence_check_depend(struct Sequence *seq, struct Sequence *cur);
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index a7991139b3f..76335f484cf 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -5371,9 +5371,8 @@ Sequence *BKE_sequencer_add_movie_strip(bContext *C, ListBase *seqbasep, SeqLoad
 	return seq;
 }
 
-static Sequence *seq_dupli(Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag, const int flag)
+static Sequence *seq_dupli(const Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag, const int flag)
 {
-	Scene *sce_audio = scene_to ? scene_to : scene;
 	Sequence *seqn = MEM_dupallocN(seq);
 
 	seq->tmp = seqn;
@@ -5416,7 +5415,7 @@ static Sequence *seq_dupli(Scene *scene, Scene *scene_to, Sequence *seq, int dup
 	else if (seq->type == SEQ_TYPE_SCENE) {
 		seqn->strip->stripdata = NULL;
 		if (seq->scene_sound)
-			seqn->scene_sound = BKE_sound_scene_add_scene_sound_defaults(sce_audio, seqn);
+			seqn->scene_sound = BKE_sound_scene_add_scene_sound_defaults(scene_to, seqn);
 	}
 	else if (seq->type == SEQ_TYPE_MOVIECLIP) {
 		/* avoid assert */
@@ -5433,7 +5432,7 @@ static Sequence *seq_dupli(Scene *scene, Scene *scene_to, Sequence *seq, int dup
 		seqn->strip->stripdata =
 		        MEM_dupallocN(seq->strip->stripdata);
 		if (seq->scene_sound)
-			seqn->scene_sound = BKE_sound_add_scene_sound_defaults(sce_audio, seqn);
+			seqn->scene_sound = BKE_sound_add_scene_sound_defaults(scene_to, seqn);
 
 		if ((flag & LIB_ID_CREATE_NO_USER_REFCOUNT) == 0) {
 			id_us_plus((ID *)seqn->sound);
@@ -5457,11 +5456,15 @@ static Sequence *seq_dupli(Scene *scene, Scene *scene_to, Sequence *seq, int dup
 		BLI_assert(0);
 	}
 
-	if (dupe_flag & SEQ_DUPE_UNIQUE_NAME)
-		BKE_sequence_base_unique_name_recursive(&scene->ed->seqbase, seqn);
+	if (scene == scene_to) {
+		if (dupe_flag & SEQ_DUPE_UNIQUE_NAME) {
+			BKE_sequence_base_unique_name_recursive(&scene_to->ed->seqbase, seqn);
+		}
 
-	if (dupe_flag & SEQ_DUPE_ANIM)
-		BKE_sequencer_dupe_animdata(scene, seq->name + 2, seqn->name + 2);
+		if (dupe_flag & SEQ_DUPE_ANIM) {
+			BKE_sequencer_dupe_animdata(scene_to, seq->name + 2, seqn->name + 2);
+		}
+	}
 
 	return seqn;
 }
@@ -5488,7 +5491,7 @@ static void seq_new_fix_links_recursive(Sequence *seq)
 	}
 }
 
-Sequence *BKE_sequence_dupli_recursive(Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag)
+Sequence *BKE_sequence_dupli_recursive(const Scene *scene, Scene *scene_to, Sequence *seq, int dupe_flag)
 {
 	Sequence *seqn;
 
@@ -5522,7 +5525,7 @@ void BKE_sequence_base_dupli_recursive(
 	for (seq = seqbase->first; seq; seq = seq->next) {
 		seq->tmp = NULL;
 		if ((seq->flag & SELECT) || (dupe_flag & SEQ_DUPE_ALL)) {
-			seqn = seq_dupli((Scene *)scene, scene_to, seq, dupe_flag, flag);
+			seqn = seq_dupli(scene, scene_to, seq, dupe_flag, flag);
 			if (seqn) { /*should never fail */
 				if (dupe_flag & SEQ_DUPE_CONTEXT) {
 					seq->flag &= ~SEQ_ALLSEL;
diff --git a/source/blender/editors/space_sequencer/sequencer_edit.c b/source/blender/editors/space_sequencer/sequencer_edit.c
index 1ace61481a6..b22a158e151 100644
--- a/source/blender/editors/space_sequencer/sequencer_edit.c
+++ b/source/blender/editors/space_sequencer/sequencer_edit.c
@@ -727,7 +727,7 @@ static Sequence *cut_seq_hard(Scene *scene, Sequence *seq, int cutframe)
 
 	if (!skip_dup) {
 		/* Duplicate AFTER the first change */
-		seqn = BKE_sequence_dupli_recursive(scene, NULL, seq, SEQ_DUPE_UNIQUE_NAME | SEQ_DUPE_ANIM);
+		seqn = BKE_sequence_dupli_recursive(scene, scene, seq, SEQ_DUPE_UNIQUE_NAME | SEQ_DUPE_ANIM);
 	}
 	
 	if (seqn) {
@@ -820,7 +820,7 @@ static Sequence *cut_seq_soft(Scene *scene, Sequence *seq, int cutframe)
 
 	if (!skip_dup) {
 		/* Duplicate AFTER the first change */
-		seqn = BKE_sequence_dupli_recursive(scene, NULL, seq, SEQ_DUPE_UNIQUE_NAME | SEQ_DUPE_ANIM);
+		seqn = BKE_sequence_dupli_recursive(scene, scene, seq, SEQ_DUPE_UNIQUE_NAME | SEQ_DUPE_ANIM);
 	}
 	
 	if (seqn) {
@@ -2162,7 +2162,7 @@ static int sequencer_add_duplicate_exec(bContext *C, wmOperator *UNUSED(op))
 	if (ed == NULL)
 		return OPERATOR_CANCELLED;
 
-	BKE_sequence_base_dupli_recursive(scene, NULL, &nseqbase, ed->seqbasep, SEQ_DUPE_CONTEXT, 0);
+	BKE_sequence_base_dupli_recursive(scene, scene, &nseqbase, ed->seqbasep, SEQ_DUPE_CONTEXT, 0);
 
 	if (nseqbase.first) {
 		Sequence *seq = nseqbase.first;
@@ -3200,7 +3200,7 @@ static int sequencer_copy_exec(bContext *C, wmOperator *op)
 		return OPERATOR_CANCELLED;
 	}
 
-	BKE_sequence_base_dupli_recursive(scene, NULL, &nseqbase, ed->seqbasep, SEQ_DUPE_UNIQUE_NAME, 0);
+	BKE_sequence_base_dupli_recursive(scene, scene, &nseqbase, ed->seqbasep, SEQ_DUPE_UNIQUE_NAME, 0);
 
 	/* To make sure the copied strips have unique names between each other add
 	 * them temporarily to the end of the original seqbase. (bug 25932)
@@ -3267,7 +3267,7 @@ static int sequencer_paste_exec(bContext *C, wmOperator *UNUSED(op))
 	ED_sequencer_deselect_all(scene);
 	ofs = scene->r.cfra - seqbase_clipboard_frame;
 
-	BKE_sequence_base_dupli_recursive(scene, NULL, &nseqbase, &seqbase_clipboard, SEQ_DUPE_UNIQUE_NAME, 0);
+	BKE_sequence_base_dupli_recursive(scene, scene, &nseqbase, &seqbase_clipboard, SEQ_DUPE_UNIQUE_NAME, 0);
 
 	/* transform pasted strips before adding */
 	if (ofs) {