Mod makers - why do they not use diffs?

MarkR

These people who make "mods" for (for example), PHPBB and the like.

Why do they not use unified diffs like everyone else uses for all other software?

They instead, post human-readable instructions, often complicated. It is almost impossible for me to become a human patching machine and correctly follow them.

Is it because:

They have never heard of diff and patch?
They think that their users haven't heard of diff and patch AND are unprepared to install them?
They are just sadists and enjoy the thrill of imagining their users incorrectly patching the application and screwing it up royally?

Mark

piersk

Funny you should mention this, cos I've started doing some work as "bug swatter" for Battle Torrent (aka blog torrent). They ask that I post changes as a patch. I use tortoise cvs which handily makes patches. Is that what you'd prefer?

MarkR

Patches are obviously the preferred form of any mod / enhancement.

They can be applied quickly and in an error-free fashion. They can be removed just as easily (patch -R)

But these weirdos who make stuff like mods for PHPBB, oscommerce, and other useful apps, appear to prefer not to use patches. I don't know why.

Mark

goldbug

Could it be because PHP apps don't have to run on *nix? Last I checked, Windows didn't come with patch/diff. If you're going to the "trouble" to rely on .diff files, you're going to also have to show windows users how to install+use an equivalent tool. At that point, you might as well just show them what to change manually, as it might be faster, and possibly less error prone than teaching tool setup + usage.

Kudose

I am one of those guys that do the mods you speak of...

I don't do patches because there is no system in place to do so.

Also, it's just easier to write code changing instructions because it is impossible (without a patch system in place) to tell what mods the user has installed. Or if the user is a programmer and did a bunch of stuff his or herself.

MarkR

goldbug: True, Windows does not come with "patch" and "diff" programs. It doesn't come with Macromedia Dreamweaver either, and lots of people use that.

Seriously though, there are plenty of versions of these programs for Windows, some with GUI front-ends.

Kudose: I don't see how you can argue that manual instructions are either
- Better
or
- Faster

patch is not completely stupid. It is capable of installing most patches over other (compatible) patches, and gives feedback to the user to indicate where it failed so they can manually merge.

Moreover, patch can easily be used in reverse to "undo" a patch.

Patch is capable of patching much more quickly and accurately than a human, even for the simplest and shortest patch instructions.

If you have a complicated patch which contains, say 100 "hunks" to patch, then it quickly gets VERY tedious, and the chance to make a mistake is close to 100%.

Mark

Kudose

I never said that they were better or faster. I said that they were easier.

It's easier becuase I don't have to worry about creating a patch system for something that isn't even mine.

Now if a patch handling system is already in place, then I'm all for simplicity.

MarkR

Hmm perhaps you don't understand:

A patch is a file describing a set of of changes between one set of (text) files and another. All it is, is a list of edits with line numbers, and context information.

"diff" is the program which makes patches

"patch" is the program which applies patches (it can also undo them)

The clever bit is, that you would normally add context to a patch, so that if the files had been changed in some small (and compatible) way, the patch COULD STILL be applied.

So in theory, if they don't conflict, you can stack several patches and have it still work. of course the more you apply, the less likely it becomes. And just because the patch applies successfully does not mean the app is going to work.

Things like Linux have always had patches - people create a patch file of their changes based on a given base version - although it typically works with other versions as long as they're sufficiently similar. This is in fact, one of the primary means of people submitting functionality to Linux.

We'd still be on Linux 0.99 if every time someone sent a patch to linus it said

FIND THIS LINE in something.c;
blah = 1;

THEN CHANGE IT TO this

blah = 2;

etc

Mark

Kudose

Touche.

I'm gonna check out this "diff" thing.

Thanks.

Weedpacket

Originally posted by MarkR
We'd still be on Linux 0.99 if every time someone sent a patch to linus it said...

And we wouldn't have a patchy server, either.