# Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? 11 messages from 2019-12-10 to 2019-12-15. Participants: KOLANICH, Junio C Hamano, Derrick Stolee, Jeff King, Ed Maste, Johannes Schindelin, brian m. carlson, Jakub Narebski. Thread: https://gitlist.dev/t/52425 ## KOLANICH, 2019-12-10 19:31 Subject: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: URL: https://gitlist.dev/e/E2770343-BB39-458C-835E-04F0753783C3%40mail.ru ``` Hello. https://github.com/git/git/blob/master/Documentation/technical/commit-graph.txt documents a file format for exporting commit graphs for consumption by third-party tools. But the license of this file is not permissive, and the license of git itself is GPL, so I am not allowed to use these 2 files to create an own permissive-licensed tool reading this file. This probably defeats the purpose of exporting these info and then reading it with another applications. Could the doc file be relicensed under a permissive license? ``` ## Junio C Hamano, 2019-12-10 20:10 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: URL: https://gitlist.dev/e/xmqqimmoq6vw.fsf%40gitster-ct.c.googlers.com In-Reply-To: ``` KOLANICH writes: > ... the license of git itself is GPL, so I am not > allowed to use these 2 files to create an own permissive-licensed > tool reading this file. It is a wrong conclusion, isn't it? GPL copyright protects the expression of the document, but the copyright protects only the expression, and does not protect the underlying format itself and the idea behind it. So I do not see a need to relicense the documentation text at all. ``` ## Derrick Stolee, 2019-12-10 20:38 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <70575b23-6adb-a29b-8df8-f9099f86eb0e@gmail.com> URL: https://gitlist.dev/e/70575b23-6adb-a29b-8df8-f9099f86eb0e%40gmail.com In-Reply-To: ``` On 12/10/2019 3:10 PM, Junio C Hamano wrote: > KOLANICH writes: I don't appear to have the original message? Perhaps it was directly addressed to Junio? >> ... the license of git itself is GPL, so I am not >> allowed to use these 2 files to create an own permissive-licensed >> tool reading this file. > > It is a wrong conclusion, isn't it? > > GPL copyright protects the expression of the document, but the > copyright protects only the expression, and does not protect the > underlying format itself and the idea behind it. So I do not see a > need to relicense the documentation text at all. (Insert "I am not a lawyer" warning.) I think this is the correct interpretation. One can interact with binary files as you want. In fact, there are likely privately licensed products that interact with Git's pack-files even though their format documentation is under GPL. What _could_ be problematic is repeating the documentation directly in another permissive-licensed repository. Thanks, -Stolee ``` ## Jeff King, 2019-12-10 20:50 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <20191210205056.GA14079@coredump.intra.peff.net> URL: https://gitlist.dev/e/20191210205056.GA14079%40coredump.intra.peff.net In-Reply-To: <70575b23-6adb-a29b-8df8-f9099f86eb0e@gmail.com> ``` On Tue, Dec 10, 2019 at 03:38:35PM -0500, Derrick Stolee wrote: > On 12/10/2019 3:10 PM, Junio C Hamano wrote: > > KOLANICH writes: > > I don't appear to have the original message? Perhaps it was > directly addressed to Junio? It made it to me via the list, too. > > GPL copyright protects the expression of the document, but the > > copyright protects only the expression, and does not protect the > > underlying format itself and the idea behind it. So I do not see a > > need to relicense the documentation text at all. > > (Insert "I am not a lawyer" warning.) > > I think this is the correct interpretation. One can interact with > binary files as you want. In fact, there are likely privately > licensed products that interact with Git's pack-files even though > their format documentation is under GPL. > > What _could_ be problematic is repeating the documentation directly > in another permissive-licensed repository. That's my understanding as well. That said, I would not be opposed to some kind of statement in the documentation making our view explicit. -Peff ``` ## Derrick Stolee, 2019-12-10 20:58 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <2ed3e8f1-082d-4eb3-f1f1-e1d184003ced@gmail.com> URL: https://gitlist.dev/e/2ed3e8f1-082d-4eb3-f1f1-e1d184003ced%40gmail.com In-Reply-To: <20191210205056.GA14079@coredump.intra.peff.net> ``` On 12/10/2019 3:50 PM, Jeff King wrote: > On Tue, Dec 10, 2019 at 03:38:35PM -0500, Derrick Stolee wrote: > >> On 12/10/2019 3:10 PM, Junio C Hamano wrote: >>> KOLANICH writes: >> >> I don't appear to have the original message? Perhaps it was >> directly addressed to Junio? > > It made it to me via the list, too. Hm... I have had messages from the list be delayed somehow by Gmail. >>> GPL copyright protects the expression of the document, but the >>> copyright protects only the expression, and does not protect the >>> underlying format itself and the idea behind it. So I do not see a >>> need to relicense the documentation text at all. >> >> (Insert "I am not a lawyer" warning.) >> >> I think this is the correct interpretation. One can interact with >> binary files as you want. In fact, there are likely privately >> licensed products that interact with Git's pack-files even though >> their format documentation is under GPL. >> >> What _could_ be problematic is repeating the documentation directly >> in another permissive-licensed repository. > > That's my understanding as well. That said, I would not be opposed to > some kind of statement in the documentation making our view explicit. A similar statement could apply to the following files: Documentation/technical/bitmap-format.txt Documentation/technical/commit-graph-format.txt Documentation/technical/http-protocol.txt Documentation/technical/index-format.txt Documentation/technical/long-running-process-protocol.txt Documentation/technical/pack-format.txt Documentation/technical/pack-protocol.txt Documentation/technical/protocol-capabilities.txt Documentation/technical/protocol-common.txt Documentation/technical/protocol-v2.txt and perhaps others, including future additions. Would it be better to have a new file in Documentation/technical/ that describes this view? -Stolee ``` ## Ed Maste, 2019-12-10 17:18 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: URL: https://gitlist.dev/e/CAPyFy2ALrWmH3kS5RgzQ%2BBH%2BZUiboQi0-FPLqr1qgsvtntEZCw%40mail.gmail.com In-Reply-To: <20191210205056.GA14079@coredump.intra.peff.net> ``` On Tue, 10 Dec 2019 at 15:51, Jeff King wrote: > > That's my understanding as well. That said, I would not be opposed to > some kind of statement in the documentation making our view explicit. As someone with a vested interest in permissively licensed tools that can perform some basic git-compatible operations, such a statement would be appreciated. ``` ## Junio C Hamano, 2019-12-10 22:20 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: URL: https://gitlist.dev/e/xmqqeexbrffe.fsf%40gitster-ct.c.googlers.com In-Reply-To: <20191210205056.GA14079@coredump.intra.peff.net> ``` Jeff King writes: >> What _could_ be problematic is repeating the documentation directly >> in another permissive-licensed repository. > > That's my understanding as well. That said, I would not be opposed to > some kind of statement in the documentation making our view explicit. In principle, I do not mind that either. But quite honestly, I cannot say that I am (or "want to be") all that sympathetic. It takes me some effort to convince myself that it is worth for us to spend extra brain cycles even thinking about making such statements, when those who would benefit the most from such an effort are the ones who call the software we work on "contamination" and proclaim that they cannot be bothered to spend the necessary effort to comply with the license as a waste of time. I'd be more receptive to those who are more friendly and respectful---these things tend to be mutual. ``` ## KOLANICH, 2019-12-11 00:36 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <8E1DF461-094C-4BBD-9F8A-575A45ED051B@mail.ru> URL: https://gitlist.dev/e/8E1DF461-094C-4BBD-9F8A-575A45ED051B%40mail.ru In-Reply-To: ``` > spend the necessary effort to comply with the license as a waste of time. Necessity to treat so called free software with a technique invented to deal with closed-source proprietary software by companies enjoying their walled gardens and vigorously protecting their walls integrity in courts is a clear sign that there is something wrong with the software. I don't beleive that free open-source software should to work this way. ``` ## Johannes Schindelin, 2019-12-11 12:57 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: URL: https://gitlist.dev/e/nycvar.QRO.7.76.6.1912111353400.46%40tvgsbejvaqbjf.bet In-Reply-To: <8E1DF461-094C-4BBD-9F8A-575A45ED051B@mail.ru> ``` Hi, On Wed, 11 Dec 2019, KOLANICH wrote: > > spend the necessary effort to comply with the license as a waste of time. > > Necessity to treat so called free software with a technique invented to > deal with closed-source proprietary software by companies enjoying their > walled gardens and vigorously protecting their walls integrity in courts > is a clear sign that there is something wrong with the software. I don't > beleive that free open-source software should to work this way. Seeing as the obvious effect of such a hostile statement can only be less cooperation, in particular when replying directly to a mail where the Git maintainer pointed out that there is hardly any benefit to the Git project in addressing complaints raised in a combative manner, I have to wonder whether you realize that you just sabotaged the process where quite a few people were ready to help you to get what you desire? Puzzled, Johannes ``` ## brian m. carlson, 2019-12-13 00:58 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <20191213005820.GD1334263@camp.crustytoothpaste.net> URL: https://gitlist.dev/e/20191213005820.GD1334263%40camp.crustytoothpaste.net In-Reply-To: <20191210205056.GA14079@coredump.intra.peff.net> ``` On 2019-12-10 at 20:50:56, Jeff King wrote: > On Tue, Dec 10, 2019 at 03:38:35PM -0500, Derrick Stolee wrote: > > > (Insert "I am not a lawyer" warning.) > > > > I think this is the correct interpretation. One can interact with > > binary files as you want. In fact, there are likely privately > > licensed products that interact with Git's pack-files even though > > their format documentation is under GPL. > > > > What _could_ be problematic is repeating the documentation directly > > in another permissive-licensed repository. > > That's my understanding as well. That said, I would not be opposed to > some kind of statement in the documentation making our view explicit. This is consistent with my interpretation as well. I view the documentation as a specification, and implementers are free to license their software as they see fit. They need only comply with the GPL if they wish to copy, modify, or distribute the documentation itself (or other parts of Git). I see this exactly as the situation with RFCs (e.g., TCP): they are documentation licensed under non-free terms, but there are multiple independent implementations of those RFCs under different terms (Linux, FreeBSD, and Windows, for example). The license terms of the RFCs apply only to those documents, not the implementations. -- brian m. carlson: Houston, Texas, US OpenPGP: https://keybase.io/bk2204 ``` ## Jakub Narebski, 2019-12-15 02:29 Subject: Re: Could /Documentation/technical/commit-graph.txt be relicensed under a permissive license? Message-ID: <86y2ve48zs.fsf@gmail.com> URL: https://gitlist.dev/e/86y2ve48zs.fsf%40gmail.com In-Reply-To: <70575b23-6adb-a29b-8df8-f9099f86eb0e@gmail.com> ``` Derrick Stolee writes: > On 12/10/2019 3:10 PM, Junio C Hamano wrote: >> KOLANICH writes: [...] >>> ... the license of git itself is GPL, so I am not >>> allowed to use these 2 files to create an own permissive-licensed >>> tool reading this file. >> >> It is a wrong conclusion, isn't it? >> >> GPL copyright protects the expression of the document, but the >> copyright protects only the expression, and does not protect the >> underlying format itself and the idea behind it. So I do not see a >> need to relicense the documentation text at all. > > (Insert "I am not a lawyer" warning.) > > I think this is the correct interpretation. One can interact with > binary files as you want. In fact, there are likely privately > licensed products that interact with Git's pack-files even though > their format documentation is under GPL. > > What _could_ be problematic is repeating the documentation directly > in another permissive-licensed repository. Sidenote: I wonder if JGit, which is permissively-licensed (EDL, i.e. new-style BSD) pure-Java implementation of Git, makes use of commit graph. I remember that pack bitmaps came to Git from JGit, where that feature was first implemented. Best, -- Jakub Narębski ```