Test instructions:
Select a module which language is set to "All".
Click on the Batch button.
set the batch params as such:

One will get
[04-Dec-2014 10:48:14 UTC] PHP Notice: Undefined offset: 132 in ROOT/libraries/legacy/model/admin.php on line 477
where "132" is the id of the new module

This PR does NOT solve the issue here.

Could you quickly test this at your end? If not fixing it, it should at least improve it...

same

I changed this further. If this does not work, I'm really stumped...

@Hackwar I tried to reproduce your issue, but I can't...

Where do you see the error message?

Here I'm using PHP 5.6.3 with error_reporting = E_ALL

@Hackwar forget it! I found it... sorry

... but, with your PR applied, I'm still getting this:
[Sat Dec 06 01:13:14.349446 2014] [:error] [pid 5392:tid 1648] [client 127.0.0.1:49338] PHP Notice: Undefined offset: 91 in D:\\UniServerZ\\vhosts\\smztest\\libraries\\legacy\\model\\admin.php on line 480, referer: http://my.test.smz.it/administrator/index.php?option=com_modules&view=modules

Ok, so I looked into this further and we basically have this bug everywhere where we implemented the batch feature... Please test this now again. I guess I caught all.

@Hackwar Seems to be alright now, Hannes!

While you're into the batch thing, can you look at #5304 "Problem 3"? It is a minor thing and in a way a documented "feature", but IMHO the behavior is at least... "not elegant". In #5304 (comment) I explain what I would expect as a normal behavior.

Thanks!

Hi @smanzi, I saw those issues and while we can fix those at some point in time, I would rather not complicate this PR by adding even more to it. Lets first treat this one and then tackle the rest later.

@Hackwar I totally agree! I was not asking to integrate a fix for that "glitch" into this... It was just an "Hey, take a look at that!"

I don't see any regression, so... @test success!

Tested successfully! Thank you @Hackwar for the fix.

2 tests -> RTC

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/5317.

Not RTC yet. The PR works for the components patched
I see the same issue for articles, newfeeds and categories. (When patching the same way in batchCopy () as done for contact in this PR, it solves the issue here.)

Done. I plan on investing some time into the batch code... There seem to be some more improvements possible, but I will work on that in another PR.

@test success
Confirmed now working for other components too
RTC?

Also tested the other components properly! All occurrences are now considered.

@Hackwar Thank you for the fast reaction.

Now is should be okay to set to RTC! :-)

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/5317.

Merging, thanks.

@Hackwar
I guess same changes are necessary for weblinks in its own repo.