fix [#26920] working with bones causes segmetation fault.

ITASC IK solver data wasn't being cleared when constraints were removed, would access freed memory and crash.

3 files changed, 29 insertions, 8 deletions

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index d2e48edc7ce..d3c14a9dd12 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -4019,7 +4019,9 @@ bConstraintTypeInfo *constraint_get_typeinfo (bConstraint *con)
  
 /* ---------- Data Management ------- */
 
-/* Free data of a specific constraint if it has any info */
+/* Free data of a specific constraint if it has any info.
+ * be sure to run BIK_clear_data() when freeing an IK constraint,
+ * unless DAG_scene_sort is called. */
 void free_constraint_data (bConstraint *con)
 {
 	if (con->data) {
diff --git a/source/blender/editors/object/object_constraint.c b/source/blender/editors/object/object_constraint.c
index b0f931fac35..450bd70a568 100644
--- a/source/blender/editors/object/object_constraint.c
+++ b/source/blender/editors/object/object_constraint.c
@@ -844,7 +844,8 @@ static int constraint_delete_exec (bContext *C, wmOperator *UNUSED(op))
 	Object *ob= ptr.id.data;
 	bConstraint *con= ptr.data;
 	ListBase *lb = get_constraint_lb(ob, con, NULL);
-	
+	const short is_ik= ELEM(con->type, CONSTRAINT_TYPE_KINEMATIC, CONSTRAINT_TYPE_SPLINEIK);
+
 	/* free the constraint */
 	if (remove_constraint(lb, con)) {
 		/* there's no active constraint now, so make sure this is the case */
@@ -852,6 +853,11 @@ static int constraint_delete_exec (bContext *C, wmOperator *UNUSED(op))
 		
 		ED_object_constraint_update(ob); /* needed to set the flags on posebones correctly */
 
+		/* ITASC needs to be rebuilt once a constraint is removed [#26920] */
+		if(is_ik) {
+			BIK_clear_data(ob->pose);
+		}
+
 		/* notifiers */
 		WM_event_add_notifier(C, NC_OBJECT|ND_CONSTRAINT|NA_REMOVED, ob);
 		
@@ -993,6 +999,8 @@ static int pose_constraints_clear_exec(bContext *C, wmOperator *UNUSED(op))
 	/* force depsgraph to get recalculated since relationships removed */
 	DAG_scene_sort(bmain, scene);		/* sort order of objects */	
 	
+	/* note, calling BIK_clear_data() isnt needed here */
+
 	/* do updates */
 	DAG_id_tag_update(&ob->id, OB_RECALC_DATA);
 	WM_event_add_notifier(C, NC_OBJECT|ND_CONSTRAINT, ob);
@@ -1003,7 +1011,7 @@ static int pose_constraints_clear_exec(bContext *C, wmOperator *UNUSED(op))
 void POSE_OT_constraints_clear(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Clear Constraints";
+	ot->name = "Clear Pose Constraints";
 	ot->idname= "POSE_OT_constraints_clear";
 	ot->description= "Clear all the constraints for the selected bones";
 	
@@ -1038,7 +1046,7 @@ static int object_constraints_clear_exec(bContext *C, wmOperator *UNUSED(op))
 void OBJECT_OT_constraints_clear(wmOperatorType *ot)
 {
 	/* identifiers */
-	ot->name = "Clear Constraints";
+	ot->name = "Clear Object Constraints";
 	ot->idname= "OBJECT_OT_constraints_clear";
 	ot->description= "Clear all the constraints for the active Object only";
 	
diff --git a/source/blender/makesrna/intern/rna_pose.c b/source/blender/makesrna/intern/rna_pose.c
index 9b8b23e3c47..7c5c4882253 100644
--- a/source/blender/makesrna/intern/rna_pose.c
+++ b/source/blender/makesrna/intern/rna_pose.c
@@ -470,11 +470,22 @@ static void rna_PoseChannel_constraints_remove(ID *id, bPoseChannel *pchan, Repo
 		BKE_reportf(reports, RPT_ERROR, "Constraint '%s' not found in pose bone '%s'.", con->name, pchan->name);
 		return;
 	}
+	else {
+		Object *ob= (Object *)id;
+		const short is_ik= ELEM(con->type, CONSTRAINT_TYPE_KINEMATIC, CONSTRAINT_TYPE_SPLINEIK);
+
+		remove_constraint(&pchan->constraints, con);
+
+		ED_object_constraint_update(ob);
+
+		constraints_set_active(&pchan->constraints, NULL);
 
-	// TODO
-	//ED_object_constraint_set_active(id, NULL);
-	WM_main_add_notifier(NC_OBJECT|ND_CONSTRAINT, id);
-	remove_constraint(&pchan->constraints, con);
+		if (is_ik) {
+			BIK_clear_data(ob->pose);
+		}
+
+		WM_main_add_notifier(NC_OBJECT|ND_CONSTRAINT|NA_REMOVED, id);
+	}
 }
 
 static int rna_PoseChannel_proxy_editable(PointerRNA *ptr)