{% set empty_cell %}
    <span class="empty">-- {{ 'oro.entity_merge.form.empty'|trans }} --</span>
{% endset %}

{% if convertedValue|length %}
    {{ convertedValue }}
    {{ 'oro.activitylist.merge.items.label'|transchoice(convertedValue) }}
{% else %}
    {{ empty_cell }}
{% endif %}
{% set empty_cell %}
    <span class="empty">-- {{ 'oro.entity_merge.form.empty'|trans }} --</span>
{% endset %}

{% if convertedValue|length %}
    {{ convertedValue }}
    {{ 'oro.activitylist.merge.items.label'|transchoice(convertedValue) }}
{% else %}
    {{ empty_cell }}
{% endif %}

Append or replace activities on account merge
CRM-4138: Append or replace activities on account merge
