# git vs hg commit counts? 6 messages from 2009-10-27 to 2009-10-27. Participants: Joe Perches, Junio C Hamano, Jakub Narebski, Marti Raudsepp. Thread: https://gitlist.dev/t/21367 ## Joe Perches, 2009-10-27 00:08 Subject: git vs hg commit counts? Message-ID: <1256602127.29938.8.camel@Joe-Laptop.home> URL: https://gitlist.dev/e/1256602127.29938.8.camel%40Joe-Laptop.home ``` I'm comparing linux-kernel git vs hg repositories. While testing some changes to scripts/get_maintainer.pl, I noticed that git and hg have different commit counts for the same files. For instance: $ git log --since=1-year-ago -- MAINTAINERS | \ grep -P "^commit [0-9a-f]{40,40}$" | wc -l 514 $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \ grep -P "^commit [0-9a-f]{40,40}$" | wc -l 601 Anyone have any understanding why? ``` ## Junio C Hamano, 2009-10-27 00:18 Subject: Re: git vs hg commit counts? Message-ID: <7v8wexd6zq.fsf@alter.siamese.dyndns.org> URL: https://gitlist.dev/e/7v8wexd6zq.fsf%40alter.siamese.dyndns.org In-Reply-To: <1256602127.29938.8.camel@Joe-Laptop.home> ``` Joe Perches writes: > I'm comparing linux-kernel git vs hg repositories. > > While testing some changes to scripts/get_maintainer.pl, > I noticed that git and hg have different commit counts > for the same files. > > For instance: > > $ git log --since=1-year-ago -- MAINTAINERS | \ > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > 514 > > $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \ > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > 601 > > Anyone have any understanding why? We simplify a merge history by discarding one branch when the merge result matches one of the parents. Does "hg" know how to do that as well? ``` ## Joe Perches, 2009-10-27 00:23 Subject: Re: git vs hg commit counts? Message-ID: <1256602985.29938.18.camel@Joe-Laptop.home> URL: https://gitlist.dev/e/1256602985.29938.18.camel%40Joe-Laptop.home In-Reply-To: <7v8wexd6zq.fsf@alter.siamese.dyndns.org> ``` On Mon, 2009-10-26 at 17:18 -0700, Junio C Hamano wrote: > > $ git log --since=1-year-ago -- MAINTAINERS | \ > > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > > 514 > > $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \ > > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > > 601 > > Anyone have any understanding why? > We simplify a merge history by discarding one branch when the merge result > matches one of the parents. Thanks Junio. > Does "hg" know how to do that as well? I don't know. I was hoping to get equivalent results though. Anyone know how? ``` ## Jakub Narebski, 2009-10-27 01:14 Subject: Re: git vs hg commit counts? Message-ID: URL: https://gitlist.dev/e/m3zl7dd4g6.fsf%40localhost.localdomain In-Reply-To: <1256602127.29938.8.camel@Joe-Laptop.home> ``` Joe Perches writes: > I'm comparing linux-kernel git vs hg repositories. > > While testing some changes to scripts/get_maintainer.pl, > I noticed that git and hg have different commit counts > for the same files. > > For instance: > > $ git log --since=1-year-ago -- MAINTAINERS | \ > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > 514 > > $ hg log --template="commit {node}\n" --date -365 -- MAINTAINERS | \ > grep -P "^commit [0-9a-f]{40,40}$" | wc -l > 601 > > Anyone have any understanding why? It *might* be caused by the fact that in Mercurial commit can have only up to two parents. This means that octopus merges (merge commits with more than two parents: there are a few of them in linux-kernel history) have to be represented as a set of two-parent merges. -- Jakub Narebski http://stackoverflow.com/questions/1598759/git-and-mercurial-compare-and-contrast/1599930#1599930 ``` ## Marti Raudsepp, 2009-10-27 01:16 Subject: Re: git vs hg commit counts? Message-ID: <54b33ccd0910261816x3c49d4ccr60a80a88dd4cfac9@mail.gmail.com> URL: https://gitlist.dev/e/54b33ccd0910261816x3c49d4ccr60a80a88dd4cfac9%40mail.gmail.com In-Reply-To: <7v8wexd6zq.fsf@alter.siamese.dyndns.org> ``` On Tue, Oct 27, 2009 at 2:18 AM, Junio C Hamano wrote: > We simplify a merge history by discarding one branch when the merge result > matches one of the parents.  Does "hg" know how to do that as well? 57 of the differing changesets are normal merges (probably what Junio explained) 3 are duplicate changesets in hg, probably also related to that 27 changesets are octopus merge fixups wrt octopus merges: in git, one merge commit can have an arbitrary number of parents, but in hg a merge changeset always has 2 parents -- so a octopus merge is represented as multiple distinct changesets. Marti ``` ## Joe Perches, 2009-10-27 04:14 Subject: Re: git vs hg commit counts? Message-ID: <1256616869.29938.30.camel@Joe-Laptop.home> URL: https://gitlist.dev/e/1256616869.29938.30.camel%40Joe-Laptop.home In-Reply-To: <54b33ccd0910261816x3c49d4ccr60a80a88dd4cfac9@mail.gmail.com> ``` On Tue, 2009-10-27 at 03:16 +0200, Marti Raudsepp wrote: > On Tue, Oct 27, 2009 at 2:18 AM, Junio C Hamano wrote: > > We simplify a merge history by discarding one branch when the merge result > > matches one of the parents. Does "hg" know how to do that as well? > > 57 of the differing changesets are normal merges (probably what Junio explained) > 3 are duplicate changesets in hg, probably also related to that > 27 changesets are octopus merge fixups > > wrt octopus merges: in git, one merge commit can have an arbitrary > number of parents, but in hg a merge changeset always has 2 parents -- > so a octopus merge is represented as multiple distinct changesets. Thanks. For hg support in get_maintainers, it's probably simplest to ignore the delta in number of commits as "close enough". ```