The mergeId for InspectorCSSAgent::SetPropertyTextAction is: String::format("SetPropertyText %s:%u:%s", m_styleSheet->id().utf8().data(), m_propertyIndex, m_overwrite ? "true" : "false"); But if you have two properties from different rules but the same index those would merge if edited back to back. We should include m_cssId.ordinal() in there.
Moving to the right component.
<rdar://problem/15796837>