It is tested on #3651 maybe we can merge here on review?

@zero-24 To merge is fine but there is a CS issue, we need a blank line after line 76. Once that is done, it can be merged. Thanks.

done with zero-24@55a3861 @roland-d

based on @roland-d's comment i move this here now to RTC

@zero-24
Sorry for the stupid question, what means RTC?

@jackkum

RTC is Ready to Commit so a maintainer can merge the PR

@zero-24
Thanks very much

Folks, is this taking into account the loading of the language file from core language folders AS WELL as module/language/ folder?

in com_modules/models/module.php , we use

        // Load the core and/or local language file(s).
        $lang->load($module, $client->path, null, false, true)
        ||  $lang->load($module, $client->path . '/modules/' . $module, null, false, true);

I confirm it is not.

I propose to change from

                // Load language file for module
                $lang = JFactory::getLanguage();
                $lang->load('mod_' . $module);

to

                // Load language file for module
                $basePath = JPATH_BASE;
                $lang = JFactory::getLanguage();
                $lang->load('mod_' . $module, $basePath, null, false, true)
                ||  $lang->load('mod_' . $module, $basePath . '/modules/mod_' . $module, null, false, true);

To test, use the module proposed by piotrmocko
http://www.perfect-web.co/downloads/mod_ajaxtester-lang.zip

Unzip it, chnage the lang folder to language folder and create an en-GB folder in that language folder. move the en-GB.mod_ajaxtester.ini file in the en-GB folder.
=> language/en-GB/en-GB.mod_ajaxtester.ini

then modify the xml.
take off

<languages folder="lang">
        <language tag="en-GB">en-GB.mod_ajaxtester.ini</language>
    </languages>

add the <folder>language</folder> to get:

<version>3.3.3</version>
    <files>
        <filename module="mod_ajaxtester">mod_ajaxtester.php</filename>
        <folder>language</folder>
        <folder>tmpl</folder>
        <filename>helper.php</filename>
        <filename>index.html</filename>
    </files>

save, zip and install.
Follow instructions of use from
See: #3651 (comment)

Thanks @infograf768 i have just add your fix: 9ed8cf2

Thanks. Merged.