OSL 3.0 Questions related for commercial use

[Big Diddy]

Hi,

First of all. Sorry If I not found the right topic for this or I'm maybe a little bit too stupid about the meaning and usage of prestashop with OSL 3.0 license. 

I mean, i have found some informations but I cannot believe that they are true...  

The main questions are: When and how i must share the code with customers or to general publicity?

 

Scenario 1:

I'm using prestashop as it comes and just configuring it. Maybe there are some modifications on styles and template to default one from prestashop.

 

Scenario 2:

I need to customize some core functions and will modify php files of the core and maybe core modules (3rd party modules could have another licenses?)

 

When and how I do to publish the source? (including my modifications?).

I mean. Do i need to upload it e.g. on GitHub and have to link it on my site? We are facing german market. Is there anything other/special?

How other prestashops handle it? 

I hope anyone can help me, thanks!

best regards