Fix: Select all didnt' work with COW pose bones

source/blender/editors/armature/pose_select.c

@@ -422,6 +422,8 @@ static int pose_de_select_all_exec(bContext *C, wmOperator *op)
 			if (multipaint || (arm->flag & ARM_HAS_VIZ_DEPS)) {
 				DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
 			}
+			/* need to tag armature for cow updates, or else selection doesn't update */
+			DEG_id_tag_update(&arm->id, DEG_TAG_COPY_ON_WRITE);
 			ob_prev = ob;
 		}
 	}