Re: [PATCH] git-p4.py: Make submit working on bare repository
Junio C Hamano writes: > Amadeusz Żołnowski writes: > >>> Has anything happened to this topic after this? I am wondering if I >>> should discard the topic az/p4-bare-no-rebase without prejudice. I think you can discard the topic, because we're moving away from Perforce and while I have tested my original patch I haven't found time to change it to --skip-rebase option as suggested and test it. Thanks, -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
Amadeusz Żołnowski writes: >> Has anything happened to this topic after this? I am wondering if I >> should discard the topic az/p4-bare-no-rebase without prejudice. > > Sorry, I haven't got time to take a loot at this, but I'll return to > that soon, OK? I'll prepare a patch with an option to skip rebase rather > than do it only for bare repos. No hurries. With or without an option, I think the documentation needs to clarify when it is safe to omit rebase and why. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Hi, Junio C Hamano writes: > Has anything happened to this topic after this? I am wondering if I > should discard the topic az/p4-bare-no-rebase without prejudice. Sorry, I haven't got time to take a loot at this, but I'll return to that soon, OK? I'll prepare a patch with an option to skip rebase rather than do it only for bare repos. -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
Luke Diamand writes: > On 28 February 2016 at 20:46, Amadeusz Żołnowski wrote: > >> >> True. For now I have these cases covered by wrapper scripts. The minimum >> I need from git-p4 is just not to fail on git submit from bare >> repository which is covered by patch I have submitted. If I get my >> solution enough testing, I'd think of transforming it into patch for >> git-p4.py as well. > > Could you change the patch to add a command-line option to suppress > the rebase? I think this would be a bit more obvious: instead of > having some special magical behaviour kick-in on a bare repo, git-p4 > just does what it's told on the command-line. > > It means that if we find another situation where we don't want to > rebase, we don't have an ever-growing list of special-case > circumstances, which could become hard to make sense of in future. > Instead, the user (who hopefully knows better) just tells git-p4 what > to do. Has anything happened to this topic after this? I am wondering if I should discard the topic az/p4-bare-no-rebase without prejudice. Thanks. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
On 28 February 2016 at 20:46, Amadeusz Żołnowski wrote: > > True. For now I have these cases covered by wrapper scripts. The minimum > I need from git-p4 is just not to fail on git submit from bare > repository which is covered by patch I have submitted. If I get my > solution enough testing, I'd think of transforming it into patch for > git-p4.py as well. Could you change the patch to add a command-line option to suppress the rebase? I think this would be a bit more obvious: instead of having some special magical behaviour kick-in on a bare repo, git-p4 just does what it's told on the command-line. It means that if we find another situation where we don't want to rebase, we don't have an ever-growing list of special-case circumstances, which could become hard to make sense of in future. Instead, the user (who hopefully knows better) just tells git-p4 what to do. Thanks! Luke -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Luke Diamand writes: > On 23 February 2016 at 20:56, Amadeusz Żołnowski wrote: >> >> To simplify things, why not just update ref during submit from bare >> repository? As you have pointed out, if user invokes submit in this >> context he/she actually wants to submit from bare repo and probably >> knows what he/she is doing - especially if he/she reads man page. (-: > > Will it do something sensible if anything goes wrong? > > I'm thinking about what happens if you submit and one of the commits > fails to go to P4 due to a merge conflict. Handling failures in this case is a bit tricky, indeed. > But I guess just doing an update-ref could be an OK thing to do. > Without actually trying it out for real though I can't be sure. It > might make sense to get some practical experience of how this works > out. True. For now I have these cases covered by wrapper scripts. The minimum I need from git-p4 is just not to fail on git submit from bare repository which is covered by patch I have submitted. If I get my solution enough testing, I'd think of transforming it into patch for git-p4.py as well. -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
On 23 February 2016 at 20:56, Amadeusz Żołnowski wrote: > > To simplify things, why not just update ref during submit from bare > repository? As you have pointed out, if user invokes submit in this > context he/she actually wants to submit from bare repo and probably > knows what he/she is doing - especially if he/she reads man page. (-: Will it do something sensible if anything goes wrong? I'm thinking about what happens if you submit and one of the commits fails to go to P4 due to a merge conflict. But I guess just doing an update-ref could be an OK thing to do. Without actually trying it out for real though I can't be sure. It might make sense to get some practical experience of how this works out. Luke -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Hi Luke, Luke Diamand writes: > I'm guessing that the reason for using a bare repo is so that changes > can be pushed to it from several different git repos. This then saves > doing the initial git-p4 clone multiple times. I have created a Git repository acting as a bridge between Perforce and pure Git repos. Changes pushed to master branch on this bridge repo get submitted to Perforce repository (referenced via remote p4/master). > If this had actually worked, I think the next thing I would want to do > is to rebase one or more branches in the bare repo against p4/master. > I don't think there's any way that git-p4 can work out which branches > would be rebased, and nor should it. It actually has all information needed. It submits commits from a given branch to a branch specified with --branch option (or default p4 remote). When submitting from a non-bare repo git-p4 has the same set of information: the current branch and a branch specified with --branch (or default p4 remote). > I think the approach of using a submitFromBare config variable to > force the user to make a choice feels a bit bogus, since they clearly > *want* to submit from this bare repo, as otherwise they wouldn't have > done "git-p4 submit" in the first place. I agree, a good point. > It might make sense to have a command-line or config option > ("--skip-rebase" ?) to tell "submit" to only do the submit part, and > skip the rebase stage (and get the rebase stage to give a more useful > error message on a bare repo when the option isn't used). That would > then mean that git-p4 does not have to know if it's running in a bare > repo or not, and the submit-without-rebase functionality is available > to people doing other different things not involving bare repos (which > we haven't though of yet) but still requiring submit without rebase. While having additional --skip-rebase is a good idea, having git-p4 doing rebase would be more elegant for those who actually use GitP4 in bare repository. In message 87fuwnd4u7@freja.aidecoe.name I have described how state of branches changes during submit. It clearly shows that in case of a bare repository it ends up in undesired state. To simplify things, why not just update ref during submit from bare repository? As you have pointed out, if user invokes submit in this context he/she actually wants to submit from bare repo and probably knows what he/she is doing - especially if he/she reads man page. (-: Kind regards, -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
On 23 February 2016 at 06:59, Junio C Hamano wrote: > Amadeusz Żołnowski writes: > >> Junio C Hamano writes: >>> I wonder if it makes sense to just silently allowing submit without >>> rebasing, and without telling the user how to clean it up. >> >> It is a good point. Maybe submit shouldn't be allowed by default at all >> From bare repository. What do you think about following approach? If >> core.base is true, then if git-p4.submitFromBare is also true then >> submit without performing proper rebase, but update master ref from >> p4/master. If core.base is true, but git-p4.submitFromBare is false, >> abort immediately. Submitting from bare repository would require aware >> decision from a user. > > (I think you meant "bare" where you wrote "base" in the above). > > As a non user of git-p4, the above sounds a safe and sensible > approach, but I'd like to hear from Luke, who has been active in > this area and is far more expert than I am ;-) Sorry, I've been travelling so not been able to reply earlier. Jetlag has now kicked-in, and 4am is the perfect time to reply to this! I think it would help to understand why we're doing a git-p4 submit from a bare repo in the first place. The usual workflow is you have a normal repo and submit from that. I'm guessing that the reason for using a bare repo is so that changes can be pushed to it from several different git repos. This then saves doing the initial git-p4 clone multiple times. As Amadeusz pointed out, the submit fails: $ git p4 submit --git-dir=/path/to/bare/repo ... ... fatal: This operation must be run in a work tree Some files in your working directory are modified and different than what is in your index. You can use git update-index to bring the index up-to-date or stash away all your changes with git stash. If this had actually worked, I think the next thing I would want to do is to rebase one or more branches in the bare repo against p4/master. I don't think there's any way that git-p4 can work out which branches would be rebased, and nor should it. I think the approach of using a submitFromBare config variable to force the user to make a choice feels a bit bogus, since they clearly *want* to submit from this bare repo, as otherwise they wouldn't have done "git-p4 submit" in the first place. It might make sense to have a command-line or config option ("--skip-rebase" ?) to tell "submit" to only do the submit part, and skip the rebase stage (and get the rebase stage to give a more useful error message on a bare repo when the option isn't used). That would then mean that git-p4 does not have to know if it's running in a bare repo or not, and the submit-without-rebase functionality is available to people doing other different things not involving bare repos (which we haven't though of yet) but still requiring submit without rebase. Luke > > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Amadeusz Żołnowski writes: > Junio C Hamano writes: >> I wonder if it makes sense to just silently allowing submit without >> rebasing, and without telling the user how to clean it up. > > It is a good point. Maybe submit shouldn't be allowed by default at all > From bare repository. What do you think about following approach? If > core.base is true, then if git-p4.submitFromBare is also true then > submit without performing proper rebase, but update master ref from > p4/master. If core.base is true, but git-p4.submitFromBare is false, > abort immediately. Submitting from bare repository would require aware > decision from a user. (I think you meant "bare" where you wrote "base" in the above). As a non user of git-p4, the above sounds a safe and sensible approach, but I'd like to hear from Luke, who has been active in this area and is far more expert than I am ;-) Thanks. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Junio C Hamano writes: > I wonder if it makes sense to just silently allowing submit without > rebasing, and without telling the user how to clean it up. It is a good point. Maybe submit shouldn't be allowed by default at all From bare repository. What do you think about following approach? If core.base is true, then if git-p4.submitFromBare is also true then submit without performing proper rebase, but update master ref from p4/master. If core.base is true, but git-p4.submitFromBare is false, abort immediately. Submitting from bare repository would require aware decision from a user. Kind regards, -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
Amadeusz Żołnowski writes: > To submit changes from master branch to Perforce, new commits should be > based on a remote branch p4/master: > > (1) > E'---F' master > / > A---B---C---D p4/master > > Commits from A to D map to Perforce changelists. These commits include > additional metadata in commit message which most important is changelist > number. > > On submit git-p4 prepares changelists for commits E'-F' and submits > these to Perforce repository. After this operation it syncs back remote > branch p4/master. This is the common part for both bare and non-bare > repository. > > (2) > E'---F' master > / > A---B---C---D---E---F p4/master > > In non-bare repository git rebase is performed and it results in > following state: > > (3) > A---B---C---D---E---F p4/master, master That is because you would want your further work to be built on top of F, not F'. > In bare repository this operation cannot be performed, so it remains in > state (2). And that is what made me wonder. > With special care state (2) can be transformed to state (3) with manual > update of refs/heads/master with refs/remotes/p4/master. What do you mean by transforming with special care? Do you mean running $ git update-ref master remotes/p4/master or does it involve something else? Is it a fairly involved procedure, I wonder if it makes sense to just silently allowing submit without rebasing, and without telling the user how to clean it up. And if it is really is the matter of update-ref, wouldn't that procedure apply equally well to a submit made from a non-bare repository? > I understand that implementing rebase for bare repository is unsafe and > it wouldn't be appreciated. Therefore we have to resort to such a > barbarity and git-p4 submit shouldn't attempt to perform a rebase > operation itself. Especially because it performs other operations before > and we end up in the intermediate state (2) anyway. > > Is this explanation satisfactory? Not quite yet. It is better than no explanation, but it does not quite convince me (a non-git-p4 user) that it makes sense to allow submitting in a bare repository in the first place. This is not an informed objection; I want to first understand why doing this is safe and does not hurt the end users. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] git-p4.py: Make submit working on bare repository
Hi Junio, To submit changes from master branch to Perforce, new commits should be based on a remote branch p4/master: (1) E'---F' master / A---B---C---D p4/master Commits from A to D map to Perforce changelists. These commits include additional metadata in commit message which most important is changelist number. On submit git-p4 prepares changelists for commits E'-F' and submits these to Perforce repository. After this operation it syncs back remote branch p4/master. This is the common part for both bare and non-bare repository. (2) E'---F' master / A---B---C---D---E---F p4/master In non-bare repository git rebase is performed and it results in following state: (3) A---B---C---D---E---F p4/master, master In bare repository this operation cannot be performed, so it remains in state (2). With special care state (2) can be transformed to state (3) with manual update of refs/heads/master with refs/remotes/p4/master. I understand that implementing rebase for bare repository is unsafe and it wouldn't be appreciated. Therefore we have to resort to such a barbarity and git-p4 submit shouldn't attempt to perform a rebase operation itself. Especially because it performs other operations before and we end up in the intermediate state (2) anyway. Is this explanation satisfactory? If yes, I'll include it in patch description. Kind regards, -- Amadeusz Żołnowski signature.asc Description: PGP signature
Re: [PATCH] git-p4.py: Make submit working on bare repository
Amadeusz Żołnowski writes: > git-p4 can be successfully used from bare repository (which may act as a > bridge between Perforce repository and pure Git repositories). After > submitting changelist to Perforce, git-p4 performs unconditional rebase > which obviously fails. > > Perform rebase only on non-bare repositories, so submit command can be > successful on bare repository. It is obvious that an attempt to run rebase would fail in a bare repository, and skipping it would obviously make it not fail. I think that part is well understood. What is unclear is what the ramification of _not_ rebasing after submitting is. In other words, why do we have to rebase after submitting when we are in a non-bare repository? There must be a reason behind it, i.e. "If we do not rebase, then the repository would be in a state where future operations like X and Y do not work correctly because of Z". And why does that same reason Z not apply when we submit from a bare repository? A possible explanation might be that X and Y are operations that happen only in a non-bare repository that we do not have to worry about happening in a bare repository after we finish submitting. But these X, Y and Z are left unexplained--that is what is unclear in the original proposed log message, and it is still unclear in the above update. Thanks. > Signed-off-by: Amadeusz Żołnowski > --- > git-p4.py | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/git-p4.py b/git-p4.py > index c33dece..e00cd02 100755 > --- a/git-p4.py > +++ b/git-p4.py > @@ -2059,8 +2059,9 @@ class P4Submit(Command, P4UserMap): > sync.branch = self.branch > sync.run([]) > > -rebase = P4Rebase() > -rebase.rebase() > +if not gitConfigBool("core.bare"): > +rebase = P4Rebase() > +rebase.rebase() > > else: > if len(applied) == 0: -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html