- end_ys[d] = dir_
- * max (max (dir_ * (base_attachments_[d][Y_AXIS]
- + parameters_.region_size_ * dir_),
- dir_ * (dir_ + extremes_[d].note_column_->extent (common_[Y_AXIS], Y_AXIS)[dir_])),
- dir_ * base_attachments_[-d][Y_AXIS]);
+ Interval nc_extent = extremes_[d].note_column_
+ ->extent (common_[Y_AXIS], Y_AXIS);
+ if (nc_extent.is_empty ())
+ slur_->warning ("slur trying to encompass an empty note column.");
+ else
+ end_ys[d] = dir_
+ * max (max (dir_ * (base_attachments_[d][Y_AXIS]
+ + parameters_.region_size_ * dir_),
+ dir_ * (dir_ + nc_extent[dir_])),
+ dir_ * base_attachments_[-d][Y_AXIS]);
+ }
+ else if (extremes_[d].slur_head_)
+ {
+ // allow only minimal movement
+ end_ys[d] = base_attachments_[d][Y_AXIS] + 0.3 * dir_;