Manual:MigrateImageCommentTemp.php

Details
migrateImageCommentTemp.php  merges   into the   table.

table is a temporary table creating a relation between each row of the  table and a row of the   table. It has been created to avoid blocking on an alter of the  table. On large wikis like Wikimedia Commons, altering the  table is a months-long process. table is being created to avoid such an alter, and will be merged back into the table in the future.

The image_comment_temp table was introduced in. See also table.

In MediaWiki 1.32, the  table is merged into the   table with. After that, the  table is removed.

This script runs by default when you runs.

Options/Arguments
This script does not take any options or arguments.

Common error
If you run this script directly then you will get this error as this script requires  field in the   table. So the best way to run this script is to run through the.
 * Run update.php to create img_description_id.

It means there is nothing to do as  table is not exist. All the work is already done.
 * image_comment_temp does not exist, so nothing to do.

It means that even after running the script there are some row are orphaned. in this case, you can run the script again or can check orphane row manually.
 * Ignoring $count orphaned image_comment_temp row(s).