3 ms·

There is a related oddity in GPL 2: when distributing modified source code you must put a mini changelog in the file itself (clause 2. b). Nobody does that any

by Tomte 2y ago

There is a related oddity in GPL 2: when distributing modified source code you must put a mini changelog in the file itself (clause 2. b). Nobody does that anymore. We have git, and before that we had SVN and CVS and so on. The legal commentaries I know simply say "in principle that requirement is legally valid and you must do it this way, it practice no programmer seems to do that, so shrug".

jchw 2y ago
> There is a related oddity in GPL 2: when distributing modified source code you must put a mini changelog in the file itself (clause 2. b). Are you referencing the right license/clause? I don't actually see how GPLv2's clause 2. b would require this actually. > Nobody does that anymore. We have git, and before that we had SVN and CVS and so on. Yep, I will agree with you that pretty much nobody actually does this, and it does not seem like it is an obstacle so far, e.g. I have not seen legal contention over this, mostly just discussion. And honestly, writing a mini-changelog definitely seems like overkill with version control, and perhaps in most cases version control metadata is a perfectly acceptable substitute. However, since the file(s) might be distributed outside of version control where the version control data might not be present (e.g. like a release tarball) having at least the copyright information in each file seems useful. Whether it satisfies the "prominent notice that the file is changed" requirement is actually not 100% certain, but I can't imagine it puts you in a worse position to do so.
- Tomte 2y ago
  Yes, I meant 2. a: "You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change."
tempfile 2y ago
I don't think clause 2b says that, do you perhaps mean clause 2a? In GPLv2 that says: > a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. while in GPLv3 it says > a) The work must carry prominent notices stating that you modified it, and giving a relevant date. Note that git/svn are not always relevant. In particular, it is not uncommon to distribute release code with the .git directory stripped - this does not excuse you from the requirement. Having said that, I had a quick glance at Linux, and picking a file at random it did have a copyright header, but certainly not one that included a record of every change. https://github.com/torvalds/linux/blob/master/init/calibrate.c https://github.com/torvalds/linux/blob/master/init/calibrate... So it doesn't look like this is peculiar to v2. But it does seem like people don't follow the letter of the requirement. I wonder if the FSF has ever clarified this.
- Sophira 2y ago
  My understanding is that most projects that are licensed with GPLv2 actually say that they're licensed for GPLv2 "or any later version" (the Linux kernel being a notable exception). So, you could use GPLv3 instead, which would allow you to just say that the work itself has changed, not the individual files.
  - tempfile 2y ago
    I don't think this is actually a significant difference between GPLv2 and v3. At the bottom of the quoted list of requirements, v2 says: > These requirements apply to the modified work as a whole. It is possible that v3's wording was cleaned up to make it clearer that individual file-level changes were not required. I have no doubt that git history would be considered sufficient metadata provided it was included in a release. We probably will never see a court test the attribution requirement in enough detail to settle this (in other words, it probably doesn't matter)

by Tomte 2y ago

jchw 2y ago

> There is a related oddity in GPL 2: when distributing modified source code you must put a mini changelog in the file itself (clause 2. b). Are you referencing the right license/clause? I don't actually see how GPLv2's clause 2. b would require this actually. > Nobody does that anymore. We have git, and before that we had SVN and CVS and so on. Yep, I will agree with you that pretty much nobody actually does this, and it does not seem like it is an obstacle so far, e.g. I have not seen legal contention over this, mostly just discussion. And honestly, writing a mini-changelog definitely seems like overkill with version control, and perhaps in most cases version control metadata is a perfectly acceptable substitute. However, since the file(s) might be distributed outside of version control where the version control data might not be present (e.g. like a release tarball) having at least the copyright information in each file seems useful. Whether it satisfies the "prominent notice that the file is changed" requirement is actually not 100% certain, but I can't imagine it puts you in a worse position to do so.

Tomte 2y ago
Yes, I meant 2. a: "You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change."

tempfile 2y ago

I don't think clause 2b says that, do you perhaps mean clause 2a? In GPLv2 that says: > a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change. while in GPLv3 it says > a) The work must carry prominent notices stating that you modified it, and giving a relevant date. Note that git/svn are not always relevant. In particular, it is not uncommon to distribute release code with the .git directory stripped - this does not excuse you from the requirement. Having said that, I had a quick glance at Linux, and picking a file at random it did have a copyright header, but certainly not one that included a record of every change. https://github.com/torvalds/linux/blob/master/init/calibrate.c https://github.com/torvalds/linux/blob/master/init/calibrate... So it doesn't look like this is peculiar to v2. But it does seem like people don't follow the letter of the requirement. I wonder if the FSF has ever clarified this.

Sophira 2y ago
My understanding is that most projects that are licensed with GPLv2 actually say that they're licensed for GPLv2 "or any later version" (the Linux kernel being a notable exception). So, you could use GPLv3 instead, which would allow you to just say that the work itself has changed, not the individual files.
- tempfile 2y ago
  I don't think this is actually a significant difference between GPLv2 and v3. At the bottom of the quoted list of requirements, v2 says: > These requirements apply to the modified work as a whole. It is possible that v3's wording was cleaned up to make it clearer that individual file-level changes were not required. I have no doubt that git history would be considered sufficient metadata provided it was included in a release. We probably will never see a court test the attribution requirement in enough detail to settle this (in other words, it probably doesn't matter)