Copying functions from LGPL libraries?

Question

Consider the following scenario:

1. I am developing a closed-source commercial application.
2. I find a LGPL-licensed library providing some functionality I would like to use in my application.
3. Said functionality is limited to a few functions and/or classes.
4. For practical and/or technical reasons, it's not possible and/or feasible to link to the entire library, either statically or dynamically. Because of this, I copy the relevant functions/classes into my own code base.
5. To make the copied functions/classes compatible with my application and/or development environment, I make some minor modifications to them.
6. The modifications do not add any new functionality not already included in the library from which the original functions/classes where taken.

Would this be a violation of the LGPL, and if so, what would I need to do to comply with it?

I realize that I ideally should be releasing the new "library" with my modifications under LGPL, but this doesn't make much sense when the modified code can't be used on its own, thus making it completely useless to anyone else.

Answer 1

I think it would violate the LGPL agreement. You're modifing the library by taking a sub-section of it. That binds you to releasing that sub-section via open source.

How about this:

• make a smaller library that was a subset of functions / classes
• release it through sourceforge
• use that LPGL library without modification

Answer 2

Linking to LGPL code does not require you to distribute the source code, and does not make your own code LGPL. I would think that practically, legally and morally your best bet is to write a wrapper that allows you to link to the unmodified LGPL library.

Answer 3

First, if you are genuinely concerned about this, you should ask a lawyer, not a random collection of people on the Web :)

But if you really want a random dude's answer:

It would seem to only be a violation of the LGPL if you don't release a GPL'd version of your derivative library. If you have doubts, why not play it safe and just GPL the code you've modified? So what if you think it's of no use to anyone else? At least you can't be accused of an LGPL violation for not making the source freely available.