# [PATCH/RFC] [git-subtree.sh] Use raw subject and body modifier "%B" instead of "%s%n%n%b" for commit 6 messages from 2012-08-10 to 2013-01-01. Participants: Techlive Zheng, greened@obbligato.org. Thread: https://gitlist.dev/t/31223 ## Techlive Zheng, 2012-08-10 01:15 Subject: [PATCH/RFC] [git-subtree.sh] Use raw subject and body modifier "%B" instead of "%s%n%n%b" for commit Message-ID: <1344561358-2953-1-git-send-email-techlivezheng@gmail.com> URL: https://gitlist.dev/e/1344561358-2953-1-git-send-email-techlivezheng%40gmail.com ``` I don't know if it is the right place to post this patch, I have sended an email to the original author apenwarr and have no response. According to , this is the place, but says different, which is really confusing. Anyway, here I am. Recently, I imported a foreign git project as a sub directory into a main repo which I intend to maintain as primary. Due to the project I imported has its own remote repo which hosted on the github, I expected after a 'git-subtree.sh split' the newly generated subtree branch would be exactly identical to the original branch. Unfortunately, it is not. I have fixed the committer date and make everything looks the same with the original branch, but they just did not end up with same commit sha1 hash. Then, I used `git cat-file -p` to view the raw output of the both commits and found that the commit generate by git-subtree has a extra 'new-line' character appended at the end of the subject which causes the problem. I checked the source and found "%s%n%n%b" were used to generate the commit message, this works the fine when a commit has a subject as well as a body, but most of my commits only have a subject under which condition a extra 'new-line' character is appended. Instead, a raw subject and body message modifier '%B' should be used. Though I think this patch should be applied by default, but the mistake has been there for a long time, applying this patch may cause the patched git-subtree generate a different branch for those whose subtree branch has already been generated using the old git-subtree. Maybe this should be explained in the help or man page, and add a condition check or a compatible mode somehow. Techlive Zheng (1): subtree.sh: Use raw subject and body modifier "%B" instead of "%s%n%n%b" contrib/subtree/git-subtree.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 1.7.11.4 ``` ## Techlive Zheng, 2012-08-10 01:15 Subject: [PATCH] subtree.sh: Use raw subject and body modifier "%B" instead of "%s%n%n%b" Message-ID: <1344561358-2953-2-git-send-email-techlivezheng@gmail.com> URL: https://gitlist.dev/e/1344561358-2953-2-git-send-email-techlivezheng%40gmail.com In-Reply-To: <1344561358-2953-1-git-send-email-techlivezheng@gmail.com> ``` "%s%n%n%b" is not always equal to "%B". If the commit msg does not have a body, this will append an extra new-line character to the msg title which would cause the splited commit has a new sha1 hash. In most cases, this does not matter, but for a project which did not merged using this script initially, the 'split' command would not genereate the same commits as the orginal which may cause conflicts. Signed-off-by: Techlive Zheng --- contrib/subtree/git-subtree.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh index 920c664..5598210 100755 --- a/contrib/subtree/git-subtree.sh +++ b/contrib/subtree/git-subtree.sh @@ -296,7 +296,7 @@ copy_commit() # We're going to set some environment vars here, so # do it in a subshell to get rid of them safely later debug copy_commit "{$1}" "{$2}" "{$3}" - git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" | + git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%B' "$1" | ( read GIT_AUTHOR_NAME read GIT_AUTHOR_EMAIL -- 1.7.11.4 ``` ## greened@obbligato.org, 2012-08-21 01:52 Subject: Re: [PATCH/RFC] [git-subtree.sh] Use raw subject and body modifier "%B" instead of "%s%n%n%b" for commit Message-ID: <87628df1v4.fsf@waller.obbligato.org> URL: https://gitlist.dev/e/87628df1v4.fsf%40waller.obbligato.org In-Reply-To: <1344561358-2953-1-git-send-email-techlivezheng@gmail.com> ``` Techlive Zheng writes: > I don't know if it is the right place to post this patch, I have sended > an email to the original author apenwarr and have no response. According > to , > this is the place, but says > different, which is really confusing. Anyway, here I am. This is the place. > Recently, I imported a foreign git project as a sub directory into a > main repo which I intend to maintain as primary. Ok. > Due to the project I imported has its own remote repo which hosted > on the github, I expected after a 'git-subtree.sh split' the newly > generated subtree branch would be exactly identical to the original > branch. I would have thought so too. > Unfortunately, it is not. I have fixed the committer date and make > everything looks the same with the original branch, but they just did > not end up with same commit sha1 hash. Then, I used `git cat-file -p` > to view the raw output of the both commits and found that the commit > generate by git-subtree has a extra 'new-line' character appended at > the end of the subject which causes the problem. Hmm. > I checked the source and found "%s%n%n%b" were used to generate the > commit message, this works the fine when a commit has a subject as > well as a body, but most of my commits only have a subject under > which condition a extra 'new-line' character is appended. Ah. Yes, we should fix this. > Instead, a raw subject and body message modifier '%B' should be used. Ok. > Though I think this patch should be applied by default, but the mistake > has been there for a long time, applying this patch may cause the patched > git-subtree generate a different branch for those whose subtree branch > has already been generated using the old git-subtree. Maybe this should > be explained in the help or man page, and add a condition check or a > compatible mode somehow. The problem is in the split code? I'm not sure this is a big issue. I can run some experiments. -Dave ``` ## greened@obbligato.org, 2012-08-21 01:56 Subject: Re: [PATCH] subtree.sh: Use raw subject and body modifier "%B" instead of "%s%n%n%b" Message-ID: <87zk5pdn43.fsf@waller.obbligato.org> URL: https://gitlist.dev/e/87zk5pdn43.fsf%40waller.obbligato.org In-Reply-To: <1344561358-2953-2-git-send-email-techlivezheng@gmail.com> ``` Techlive Zheng writes: > "%s%n%n%b" is not always equal to "%B". If the commit msg does not have > a body, this will append an extra new-line character to the msg title > which would cause the splited commit has a new sha1 hash. In most cases, > this does not matter, but for a project which did not merged using this > script initially, the 'split' command would not genereate the same > commits as the orginal which may cause conflicts. > > Signed-off-by: Techlive Zheng > --- > contrib/subtree/git-subtree.sh | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh > index 920c664..5598210 100755 > --- a/contrib/subtree/git-subtree.sh > +++ b/contrib/subtree/git-subtree.sh > @@ -296,7 +296,7 @@ copy_commit() > # We're going to set some environment vars here, so > # do it in a subshell to get rid of them safely later > debug copy_commit "{$1}" "{$2}" "{$3}" > - git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" | > + git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%B' "$1" | > ( > read GIT_AUTHOR_NAME > read GIT_AUTHOR_EMAIL This looks good to me. I assume this passes all the tests. Can you add a test for this bug so we don't regress? Junio, I am good with this patch as soon as we get a test for the problem. Thanks! -Dave ``` ## greened@obbligato.org, 2012-12-31 22:57 Subject: Re: [PATCH] subtree.sh: Use raw subject and body modifier "%B" instead of "%s%n%n%b" Message-ID: <87mwwt4yp4.fsf@waller.obbligato.org> URL: https://gitlist.dev/e/87mwwt4yp4.fsf%40waller.obbligato.org In-Reply-To: <87zk5pdn43.fsf@waller.obbligato.org> ``` greened@obbligato.org writes: > Techlive Zheng writes: > >> "%s%n%n%b" is not always equal to "%B". If the commit msg does not have >> a body, this will append an extra new-line character to the msg title >> which would cause the splited commit has a new sha1 hash. In most cases, >> this does not matter, but for a project which did not merged using this >> script initially, the 'split' command would not genereate the same >> commits as the orginal which may cause conflicts. >> >> Signed-off-by: Techlive Zheng >> --- >> contrib/subtree/git-subtree.sh | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh >> index 920c664..5598210 100755 >> --- a/contrib/subtree/git-subtree.sh >> +++ b/contrib/subtree/git-subtree.sh >> @@ -296,7 +296,7 @@ copy_commit() >> # We're going to set some environment vars here, so >> # do it in a subshell to get rid of them safely later >> debug copy_commit "{$1}" "{$2}" "{$3}" >> - git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" | >> + git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%B' "$1" | >> ( >> read GIT_AUTHOR_NAME >> read GIT_AUTHOR_EMAIL > > This looks good to me. I assume this passes all the tests. Can you add > a test for this bug so we don't regress? Junio, I am good with this > patch as soon as we get a test for the problem. I've applied this patch to my working copy but I'm not finding that I can recreate the original problem when the patch is disabled. I assumed the scenario you're trying to fix is: - Make some commit C to project A with a one-line message - work, commit, work... - Add project A as a subproject - work, commit, work... - Split project A off into a separate repository After this, commit C with the one-line message in the split-off projet should have the same hash it had before project A was incorporated as a subproject. As I understad it, you saw the post-split commit having a different hash? Is that right? I am not seeing that problem even without your patch. I want to make sure I understand what the problem is so I can test for it. Thanks! -David ``` ## greened@obbligato.org, 2013-01-01 03:59 Subject: Re: [PATCH] subtree.sh: Use raw subject and body modifier "%B" instead of "%s%n%n%b" Message-ID: <87han1wo2y.fsf@waller.obbligato.org> URL: https://gitlist.dev/e/87han1wo2y.fsf%40waller.obbligato.org In-Reply-To: <87mwwt4yp4.fsf@waller.obbligato.org> ``` greened@obbligato.org writes: > I've applied this patch to my working copy but I'm not finding that I > can recreate the original problem when the patch is disabled. ^ not -David ```