Missing "Media" field value of image items after smart publishing

[afengisme]

Hello,
We use Sitecore 8.2 rev. 161221 with sitecore.ship installed for CI deployment and publishing, we meet a curious issue as followings:

Our site has only one language version for all items including Media Library items, that is "en-US", after installing the .update packages in the instance by http:///services/package/install/fileupload in CI process, then calling http://*/services/publish/smart with posting the forms "source=master,target=web,language=en-US" to do the publishing.

Then we found the issue:
The "Media" field value of image items with en-US version in Web database has gone.

Two approaches can fix this issue, but we still don't know the root cause:
1> Add "en" language version for the image media items, yes, adding "en" language version for them, I don't know why this can fix the issue.
2> Do "full" publishing.

If we do the publishing manually via sitecore client by clicking "Publish", there is no this issue.

Any ideas? Thanks

[pveller]

You will find the answer to your question is you look at the source code of the publish command. Here:
https://github.com/kevinobee/Sitecore.Ship/blob/develop/src/Sitecore.Ship.AspNet/Publish/InvokePublishingCommand.cs#L93

The name of the parameter is languages and it defaults to en if it can't find anything.

[afengisme]

Thanks @pveller for your replying,

I tried to do the publishing as below for "en-US" using "targets" and "languages"
.\curl.exe --show-error --silent --connect-timeout 300 --max-time 9000 --form 'source=master' --form 'targets=web' --form 'languages=en-US' http://xxxxx/services/publish/smart

Seems it never starts the publishing, I did not find any sitecore publishing logs brought by above command.

Checking the last completed publishing by:
.\curl.exe --show-error --silent --connect-timeout 300 --max-time 900 http://xxxxx/services/publish/lastcompleted/master/web/en-US

the returned value is less than the one returned by launching the publishing command all the time, looks like the launching publishing command did nothing.