Principles of Merging for Module Upgrades?

[quit]

I'm trying to get all of the modules I would like to use installed before setting up my products. So far all I have accomplished is getting SSL working, a theme installed and a couple modules like one to back up the MySQL database.

I got Super Orders installed and plan to do Edit orders as well as some of the compatible modules like USPS click-n-ship.

These modules say in the instructions:

As with ANY module, any files which override existing cart files should be merged using a tool like Winmerge or Beyond Compare before you install the module.

I already did the Super Orders install without any comparison, but now I am wondering if I am going to mess something up when I do Edit Orders.

Regardless of what program I use.. what am I even looking for when I compare? What do I need to be careful of?

To go even further, I would like to.. once I have all these crucial modules installed, but before I have really branded my theme or added much in the way of products, back up the whole configuration so I could use it again.. without having to manually install all these modules. How would I pull this off? I've been in the /admin/includes/configure.php and noticed the information on MySQL database and such, but what other files might differ and need to be changed?

Another thing that seems like a good idea is having a development setup on a subdomain.. it seems like the same sort of ideas would matter since I want to do that. Thanks all for help =)

[stevesh]

There's no shortcut I'm aware of. You have to examine the files in the mods and, where two (or more) mods edit the same file(s), you'll need to use a comparison tool like Winmerge (I use Compare It!) to compare the files against each other and against a 'clean' copy of the file from the Zencart distribution to see what changes each mod has made and 'merge' the two into one file which contains the edits of both.

In my experience (somewhat limited, since I try to keep mods to a minimum) that process can range from pretty easy to nearly impossible.

[schoolboy]

I tend to agree with Steve... Keep add-ons down to the "bare essentials". Sometimes, when a very specific type of behaviour is required, then adding another mod is inevitable.

And there is no "shortcut" to "merging" module files. I had experience of this just yesterday when I installed Tabbed Products Pro (from my archive), and it killed the new EZPage-specific stylesheet feature now embedded in 1.3.9h.

... the reason? html_header.php... I had to go edit the TPP version to incorporate the EZPages stylesheet function.

In short... no easy solutions.

There is a thread somewhere on the forum where people are trying earlier mods on 1,3,9h to address both compatibility and cros-referencing issues.