Right now when publishing Content (for example with one or two translations modified) all translations will be indexed even when they're not modified. This can cause elongated times when publishing content with plenty of translations and fields.

https://github.com/ezsystems/ezplatform-kernel/blob/1.3/eZ/Publish/API/Repository/ContentService.php#L343 - publishVersion method accepts the $translations parameter so this might be useful when later indexing content.

Steps to reproduce:

1. Use Solr or Elasticsearch as a search engine.
2. Create content with 1 language and multiple fields.
3. Modify one version and publish.
4. Note the time that it takes to publish content.
5. Add 20 languages to content from step 1.
6. Modify one version and publish.
7. Note the time that it takes to publish content.
8. Compare the times.

One would be able to observe the increased amount of time that it takes to publish content even though he has changed only a single translation.