* Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
From: John Keeping @ 2013-01-16 23:08 UTC (permalink / raw)
To: Antoine Pelisse; +Cc: Max Horn, Junio C Hamano, git, Johannes Sixt
In-Reply-To: <1358376443-7404-1-git-send-email-apelisse@gmail.com>
On Wed, Jan 16, 2013 at 11:47:22PM +0100, Antoine Pelisse wrote:
> clang incorrectly reports a constant conversion warning (implicit
> truncation to bit field) when using the "flag &= ~FLAG" form, because
> ~FLAG needs to be truncated.
>
> Convert this form to "flag = flag & ~FLAG" fixes the issue as
> the right operand now fits into the bit field.
>
> Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
> ---
> I'm sorry about this fix, it really seems bad, yet it's one step closer
> to warning-free clang compilation.
>
> It seems quite clear to me that it's a bug in clang.
Which version of clang did you see this with? I don't get these
warnings with clang 3.2.
John
^ permalink raw reply
* Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
From: Antoine Pelisse @ 2013-01-16 23:09 UTC (permalink / raw)
To: John Keeping; +Cc: Max Horn, Junio C Hamano, git, Johannes Sixt
In-Reply-To: <20130116230800.GB4574@serenity.lan>
On Thu, Jan 17, 2013 at 12:08 AM, John Keeping <john@keeping.me.uk> wrote:
> On Wed, Jan 16, 2013 at 11:47:22PM +0100, Antoine Pelisse wrote:
>> clang incorrectly reports a constant conversion warning (implicit
>> truncation to bit field) when using the "flag &= ~FLAG" form, because
>> ~FLAG needs to be truncated.
> Which version of clang did you see this with? I don't get these
> warnings with clang 3.2.
Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
It's good to know it's been fixed !
^ permalink raw reply
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: Antoine Pelisse @ 2013-01-16 23:10 UTC (permalink / raw)
To: John Keeping, Max Horn, Junio C Hamano
Cc: git, Johannes Sixt, Antoine Pelisse
In-Reply-To: <1358376443-7404-2-git-send-email-apelisse@gmail.com>
> With these two patches and the patch from Max Horne,
I'm deeply sorry for this typo Max
^ permalink raw reply
* Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
From: Antoine Pelisse @ 2013-01-16 23:15 UTC (permalink / raw)
To: John Keeping; +Cc: Max Horn, Junio C Hamano, git, Johannes Sixt
In-Reply-To: <CALWbr2ypYUvuE4pWfcVvVcnJkRvCNrM1gVHp_UXeke9gbgoE3A@mail.gmail.com>
So I guess we should drop this patch, it's probably not worth it,
especially if it's been fixed already by clang.
On Thu, Jan 17, 2013 at 12:09 AM, Antoine Pelisse <apelisse@gmail.com> wrote:
> On Thu, Jan 17, 2013 at 12:08 AM, John Keeping <john@keeping.me.uk> wrote:
>> On Wed, Jan 16, 2013 at 11:47:22PM +0100, Antoine Pelisse wrote:
>>> clang incorrectly reports a constant conversion warning (implicit
>>> truncation to bit field) when using the "flag &= ~FLAG" form, because
>>> ~FLAG needs to be truncated.
>> Which version of clang did you see this with? I don't get these
>> warnings with clang 3.2.
>
> Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
>
> It's good to know it's been fixed !
^ permalink raw reply
* Re: Question re. git remote repository
From: Matt Seitz (matseitz) @ 2013-01-16 23:32 UTC (permalink / raw)
To: git@vger.kernel.org; +Cc: ishchis2@gmail.com, david@lang.hm
"David Lang" <david@lang.hm> wrote in message news:<alpine.DEB.2.02.1301161459060.21503@nftneq.ynat.uz>...
> But if you try to have one filesystem, with multiple people running git on their
> machines against that shared filesystem, I would expect you to have all sorts of
> problems.
What leads you to think you will have problems?
Why would there be more of a problem on a network file system as opposed to local file system that can be accessed by multiple users?
Linus seemed to think it should work:
http://permalink.gmane.org/gmane.comp.version-control.git/122670
And "git init" specifically has a "shared" option:
--shared[=(false|true|umask|group|all|world|everybody|0xxx)]
Specify that the git repository is to be shared amongst several users. This allows users belonging to the same group to push into that repository. When specified, the config variable "core.sharedRepository" is set so that files and directories under $GIT_DIR are created with the requested permissions. When not specified, git will use permissions reported by umask(2).
^ permalink raw reply
* Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
From: Junio C Hamano @ 2013-01-16 23:43 UTC (permalink / raw)
To: Antoine Pelisse; +Cc: John Keeping, Max Horn, git, Johannes Sixt
In-Reply-To: <1358376443-7404-1-git-send-email-apelisse@gmail.com>
Antoine Pelisse <apelisse@gmail.com> writes:
> clang incorrectly reports a constant conversion warning (implicit
> truncation to bit field) when using the "flag &= ~FLAG" form, because
> ~FLAG needs to be truncated.
>
> Convert this form to "flag = flag & ~FLAG" fixes the issue as
> the right operand now fits into the bit field.
If the "clang incorrectly reports" is already recognised by clang
folks as a bug to be fixed in clang, I'd rather not to take this
patch.
I do not think it is reasonable to expect people to remember that
they have to write "flags &= ~TO_DROP" in a longhand whenever they
are adding new code that needs to do bit-fields, so even if this
patch makes clang silent for the _current_ code, it will not stay
that way. Something like
#define FLIP_BIT_CLR(fld,bit) do { \
typeof(fld) *x = &(fld); \
*x = *x & (~(bit)); \
} while (0)
may be more palapable but not by a large margin.
Yuck.
^ permalink raw reply
* Re: [PATCH 1/2] fix clang -Wconstant-conversion with bit fields
From: Junio C Hamano @ 2013-01-16 23:46 UTC (permalink / raw)
To: Antoine Pelisse; +Cc: John Keeping, Max Horn, git, Johannes Sixt
In-Reply-To: <7vpq14vglu.fsf@alter.siamese.dyndns.org>
Junio C Hamano <gitster@pobox.com> writes:
> Antoine Pelisse <apelisse@gmail.com> writes:
>
>> clang incorrectly reports a constant conversion warning (implicit
>> truncation to bit field) when using the "flag &= ~FLAG" form, because
>> ~FLAG needs to be truncated.
>>
>> Convert this form to "flag = flag & ~FLAG" fixes the issue as
>> the right operand now fits into the bit field.
>
> If the "clang incorrectly reports" is already recognised by clang
> folks as a bug to be fixed in clang, I'd rather not to take this
> patch.
>
> I do not think it is reasonable to expect people to remember that
> they have to write "flags &= ~TO_DROP" in a longhand whenever they
> are adding new code that needs to do bit-fields, so even if this
> patch makes clang silent for the _current_ code, it will not stay
> that way. Something like
>
> #define FLIP_BIT_CLR(fld,bit) do { \
> typeof(fld) *x = &(fld); \
> *x = *x & (~(bit)); \
> } while (0)
>
> may be more palapable but not by a large margin.
>
> Yuck.
Double yuck. I meant palatable.
In any case, I see somebody reports that more recent clang does not
have this bug in the near-by message, so let's forget about this
issue.
Thanks.
^ permalink raw reply
* Re: Question re. git remote repository
From: David Lang @ 2013-01-17 0:21 UTC (permalink / raw)
To: Matt Seitz (matseitz); +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <A0DB01D693D8EF439496BC8B037A0AEF322098A4@xmb-rcd-x15.cisco.com>
On Wed, 16 Jan 2013, Matt Seitz (matseitz) wrote:
> "David Lang" <david@lang.hm> wrote in message news:<alpine.DEB.2.02.1301161459060.21503@nftneq.ynat.uz>...
>> But if you try to have one filesystem, with multiple people running git on their
>> machines against that shared filesystem, I would expect you to have all sorts of
>> problems.
>
> What leads you to think you will have problems?
>
> Why would there be more of a problem on a network file system as opposed to
> local file system that can be accessed by multiple users?
There are safety checks and synchronization primitives that work between
mulitiple users on one machine (where you can see what other processes are
running for example) that don't work with separate machines using a filesystem
> Linus seemed to think it should work:
>
> http://permalink.gmane.org/gmane.comp.version-control.git/122670
well, he knows git better than I do, but using git over NFS/CIFS is not the same
as saying that you have multiple users on different systems making changes.
In the link you point at, he says that you can have problems with some types of
actions. He points out things like git prune, but I would also say that there
are probably race conditions if you have two git processes that try to change
the HEAD to different things at the same time.
> And "git init" specifically has a "shared" option:
>
> --shared[=(false|true|umask|group|all|world|everybody|0xxx)]
>
> Specify that the git repository is to be shared amongst several users. This
> allows users belonging to the same group to push into that repository. When
> specified, the config variable "core.sharedRepository" is set so that files
> and directories under $GIT_DIR are created with the requested permissions.
> When not specified, git will use permissions reported by umask(2).
>
I think this is dealing with multiple users _reading_ a repository, not making
updates to it at the same time.
David Lang
^ permalink raw reply
* Re: [PATCH 3/8] git_remote_helpers: Force rebuild if python version changes
From: Pete Wyckoff @ 2013-01-17 0:27 UTC (permalink / raw)
To: John Keeping; +Cc: git, Eric S. Raymond, Felipe Contreras, Sverre Rabbelier
In-Reply-To: <20130115225805.GA4574@serenity.lan>
john@keeping.me.uk wrote on Tue, 15 Jan 2013 22:58 +0000:
> For reference, putting the version check in setup.py looks like this:
>
> -- >8 --
>
> diff --git a/git_remote_helpers/setup.py b/git_remote_helpers/setup.py
> index 6de41de..2c21eb5 100644
> --- a/git_remote_helpers/setup.py
> +++ b/git_remote_helpers/setup.py
> @@ -3,6 +3,7 @@
> """Distutils build/install script for the git_remote_helpers package."""
>
> from distutils.core import setup
> +import sys
>
> # If building under Python3 we need to run 2to3 on the code, do this by
> # trying to import distutils' 2to3 builder, which is only available in
> @@ -13,6 +14,24 @@ except ImportError:
> # 2.x
> from distutils.command.build_py import build_py
>
> +
> +current_version = '%d.%d' % sys.version_info[:2]
> +try:
> + f = open('GIT-PYTHON_VERSION', 'r')
> + latest_version = f.read().strip()
> + f.close()
> +
> + if latest_version != current_version:
> + if not '--force' in sys.argv:
> + sys.argv.insert(0, '--force')
> +except IOError:
> + pass
> +
> +f = open('GIT-PYTHON_VERSION', 'w')
> +f.write(current_version)
> +f.close()
> +
> +
> setup(
> name = 'git_remote_helpers',
> version = '0.1.0',
>
That's about the same overhead as doing it in the Makefile,
and a bit more obscure. I don't mind your initial version
so much anymore. Thanks for thinking about it.
-- Pete
^ permalink raw reply
* Re: [RFC/PATCH 2/8 v3] git_remote_helpers: fix input when running under Python 3
From: Pete Wyckoff @ 2013-01-17 0:29 UTC (permalink / raw)
To: John Keeping
Cc: Junio C Hamano, Michael Haggerty, git, Eric S. Raymond,
Felipe Contreras, Sverre Rabbelier
In-Reply-To: <20130116094418.GA9089@river>
john@keeping.me.uk wrote on Wed, 16 Jan 2013 09:45 +0000:
> On Tue, Jan 15, 2013 at 07:03:16PM -0500, Pete Wyckoff wrote:
> > I'd suggest for this Python conundrum using byte-string literals, e.g.:
> >
> > lines = check_output(args).strip().split(b'\n')
> > value, name = line.split(b' ')
> > name = name.strip(b'commit\t')
> >
> > Essentially identical to what you have, but avoids naming "utf-8" as
> > the encoding. It instead relies on Python's interpretation of
> > ASCII characters in string context, which is exactly what C does.
>
> The problem is that AFAICT the byte-string prefix is only available in
> Python 2.7 and later (compare [1] and [2]). I think we need this more
> convoluted code if we want to keep supporting Python 2.6 (although
> perhaps 'ascii' would be a better choice than 'utf-8').
>
> [1] http://docs.python.org/2.6/reference/lexical_analysis.html#literals
> [2] http://docs.python.org/2.7/reference/lexical_analysis.html#literals
Drat. The b'' syntax seems to work on 2.6.8, in spite of
the docs, but certainly isn't in 2.5.
I think you had hit on the best compromise with encoding,
but maybe ascii is a little less presumptuous than utf-8,
and more indicative of the encoding assumption.
-- Pete
^ permalink raw reply
* Re: [PATCH] Add Auto-Submitted header to post-receive-email
From: Jonathan Nieder @ 2013-01-17 0:49 UTC (permalink / raw)
To: Chris Hiestand
Cc: Andy Parkins, Junio C Hamano, git, Michael Haggerty,
Kevin P. Fleming
In-Reply-To: <258F0FE2-D014-4624-A1E2-721E51F0E12C@salk.edu>
Hi Chris,
Chris Hiestand wrote:
> Andy, do you have any thoughts on adding this email header to
> contrib/hooks/post-receive-email? This patch shouldn't cause problems for anyone
> with a sanely configured mail delivery agent, and the additional header is very
> useful in toggling auto responses.
I'm not Andy, but it sounds very sane to me. So for what it's worth,
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Thanks,
Jonathan
(patch left unsnipped for reference)
> This conforms to RFC3834 and is useful in preventing eg
> vacation auto-responders from replying by default
>
> Signed-off-by: Chris Hiestand <chiestand@salk.edu>
> ---
> contrib/hooks/post-receive-email | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/contrib/hooks/post-receive-email b/contrib/hooks/post-receive-email
> index b2171a0..0e5b72d 100755
> --- a/contrib/hooks/post-receive-email
> +++ b/contrib/hooks/post-receive-email
> @@ -237,6 +237,7 @@ generate_email_header()
> X-Git-Reftype: $refname_type
> X-Git-Oldrev: $oldrev
> X-Git-Newrev: $newrev
> + Auto-Submitted: auto-generated
>
> This is an automated email from the git hooks/post-receive script. It was
> generated because a ref change was pushed to the repository containing
> --
> 1.7.10.4
^ permalink raw reply
* RE: Question re. git remote repository
From: Matt Seitz (matseitz) @ 2013-01-17 1:09 UTC (permalink / raw)
To: David Lang; +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <alpine.DEB.2.02.1301161617240.21503@nftneq.ynat.uz>
> From: David Lang [mailto:david@lang.hm]
>
> On Wed, 16 Jan 2013, Matt Seitz (matseitz) wrote:
>
> > Linus seemed to think it should work:
> >
> > http://permalink.gmane.org/gmane.comp.version-control.git/122670
>
> In the link you point at, he says that you can have problems with some
> types of
> actions. He points out things like git prune,
Linus wrote:
You do need to be a bit careful if you do maintenance operations
concurrently (I would suggest avoiding doing concurrent "git gc --prune",
for example), but any normal git workflow should be fine.
> but I would also say that there
> are probably race conditions if you have two git processes that try to
> change the HEAD to different things at the same time.
What makes you think there are race conditions?
Linus wrote:
And git doesn't have "proper locking", because it doesn't need it for
database ops: git objects are stable. For refs, git should be using the
proper NFS-safe "create and atomic rename" ops.
> > And "git init" specifically has a "shared" option:
> >
> > --shared[=(false|true|umask|group|all|world|everybody|0xxx)]
>
> I think this is dealing with multiple users _reading_ a repository, not
> making
> updates to it at the same time.
The description of "shared" says "This allows users belonging to the same group to push into that repository." The "push" command is about making updates.
^ permalink raw reply
* RE: Question re. git remote repository
From: David Lang @ 2013-01-17 1:26 UTC (permalink / raw)
To: Matt Seitz (matseitz); +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <A0DB01D693D8EF439496BC8B037A0AEF32209A54@xmb-rcd-x15.cisco.com>
On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
>> From: David Lang [mailto:david@lang.hm]
>>
>> On Wed, 16 Jan 2013, Matt Seitz (matseitz) wrote:
>>
>>> Linus seemed to think it should work:
>>>
>>> http://permalink.gmane.org/gmane.comp.version-control.git/122670
>>
>> In the link you point at, he says that you can have problems with some
>> types of
>> actions. He points out things like git prune,
>
> Linus wrote:
>
> You do need to be a bit careful if you do maintenance operations
> concurrently (I would suggest avoiding doing concurrent "git gc --prune",
> for example), but any normal git workflow should be fine.
>
>> but I would also say that there
>> are probably race conditions if you have two git processes that try to
>> change the HEAD to different things at the same time.
>
> What makes you think there are race conditions?
>
> Linus wrote:
>
> And git doesn't have "proper locking", because it doesn't need it for
> database ops: git objects are stable. For refs, git should be using the
> proper NFS-safe "create and atomic rename" ops.
As Linus points out, objects are stable, so when you create objects you don't
have to worry about locking, if two things write an object at the same time, the
same contents are being written so races don't matter.
However, if you have two people doing a commit or merge, you will get different
results based on the order they are happening in. This seems to be exactly the
type of thing that falls into the 'maintinance operations' category.
Linus says that git does not have "proper locking", so think about it, what do
you think will happen if person A does git add a/b; git commit and person B does
git add c/d; git commit?
Since the tree will look different depending on what order these four commands
execute in, the resulting HEAD could have multiple different values depending on
the order. The individual commits may even be different.
David Lang
>>> And "git init" specifically has a "shared" option:
>>>
>>> --shared[=(false|true|umask|group|all|world|everybody|0xxx)]
>>
>> I think this is dealing with multiple users _reading_ a repository, not
>> making
>> updates to it at the same time.
>
> The description of "shared" says "This allows users belonging to the same
> group to push into that repository." The "push" command is about making
> updates.
^ permalink raw reply
* RE: Question re. git remote repository
From: Matt Seitz (matseitz) @ 2013-01-17 1:46 UTC (permalink / raw)
To: David Lang; +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <alpine.DEB.2.02.1301161721110.21503@nftneq.ynat.uz>
> From: David Lang [mailto:david@lang.hm]
>
> Linus says that git does not have "proper locking", so think about it,
> what do
> you think will happen if person A does git add a/b; git commit and person
> B does
> git add c/d; git commit?
Sorry, I wasn't clear. My assumption is that a shared repository on a network file system will either be:
1. a bare repository that is normally accessed only by "git push" and "git pull" (or "git fetch"), the central repository model.
2. a repository where only one user does "git add" and "git commit", while other users will do "git pull", the peer-to-peer model (you pull changes from me, I pull changes from you).
^ permalink raw reply
* RE: Question re. git remote repository
From: David Lang @ 2013-01-17 1:59 UTC (permalink / raw)
To: Matt Seitz (matseitz); +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <A0DB01D693D8EF439496BC8B037A0AEF32209AD2@xmb-rcd-x15.cisco.com>
On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
>> From: David Lang [mailto:david@lang.hm]
>>
>> Linus says that git does not have "proper locking", so think about it,
>> what do
>> you think will happen if person A does git add a/b; git commit and person
>> B does
>> git add c/d; git commit?
>
> Sorry, I wasn't clear. My assumption is that a shared repository on a network file system will either be:
>
> 1. a bare repository that is normally accessed only by "git push" and "git pull" (or "git fetch"), the central repository model.
pulling from it would not be a problem, I could see issues with multiple pushes
taking place (the underlying repository would not get corrupted, but you will
very quickly hit conflicts where the push is not a fast forward and you need to
merge, not just push)
> 2. a repository where only one user does "git add" and "git commit", while
> other users will do "git pull", the peer-to-peer model (you pull changes from
> me, I pull changes from you).
At this point only one system is writing to the repository and it doesn't matter
that it's on network storage vs local storage.
pulling from a shared repository is probably safe, but I wouldn't bet against
there being any conditions where a pull at the same time someone is doing an
update being able to cause problems.
The normal thing is to do the pulls through git-daemon, and that does make sure
that what you are pulling is consistant.
David Lang
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Chris Rorvick @ 2013-01-17 2:19 UTC (permalink / raw)
To: Jeff King
Cc: Junio C Hamano, Max Horn, git, Angelo Borsotti, Drew Northup,
Michael Haggerty, Philip Oakley, Johannes Sixt, Kacper Kornet,
Felipe Contreras
In-Reply-To: <20130116174325.GA27525@sigill.intra.peff.net>
On Wed, Jan 16, 2013 at 11:43 AM, Jeff King <peff@peff.net> wrote:
> I think that is a reasonable rule that could be applied across all parts
> of the namespace hierarchy. And it could be applied by the client,
> because all you need to know is whether ref->old_sha1 is reachable from
> ref->new_sha1.
is_forwardable() did solve a UI issue. Previously all instances where
old is not reachable by new were assumed to be addressable with a
merge. is_forwardable() attempted to determine if the concept of
forwarding made sense given the inputs. For example, if old is a blob
it is useless to suggest merging it.
Chris
^ permalink raw reply
* RE: Question re. git remote repository
From: Matt Seitz (matseitz) @ 2013-01-17 2:25 UTC (permalink / raw)
To: David Lang; +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <alpine.DEB.2.02.1301161756240.21503@nftneq.ynat.uz>
> From: David Lang [mailto:david@lang.hm]
>
> On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
>
> > 1. a bare repository that is normally accessed only by "git push" and
> > "git pull" (or "git fetch"), the central repository model.
>
> pulling from it would not be a problem, I could see issues with multiple
> pushes taking place (the underlying repository would not get corrupted, but you
> will very quickly hit conflicts where the push is not a fast forward and you
> need to merge, not just push)
How is that different on a network file system, as opposed to using http, ssh, or git-daemon? Don't you get a "not a fast-forward" error, regardless of the protocol?
> > 2. a repository where only one user does "git add" and "git commit",
> while
> > other users will do "git pull", the peer-to-peer model (you pull changes
> from
> > me, I pull changes from you).
>
>
> pulling from a shared repository is probably safe, but I wouldn't bet
> against
> there being any conditions where a pull at the same time someone is doing
> an
> update being able to cause problems.
Why do you think there would be a problem?
> The normal thing is to do the pulls through git-daemon, and that does make
> sure
> that what you are pulling is consistant.
What does "git pull" via git-daemon do to ensure consistency that is different from "git pull" on a network file system?
^ permalink raw reply
* RE: Question re. git remote repository
From: David Lang @ 2013-01-17 2:49 UTC (permalink / raw)
To: Matt Seitz (matseitz); +Cc: git@vger.kernel.org, ishchis2@gmail.com
In-Reply-To: <A0DB01D693D8EF439496BC8B037A0AEF32209B45@xmb-rcd-x15.cisco.com>
On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
>> From: David Lang [mailto:david@lang.hm]
>>
>> On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
>>
>>> 1. a bare repository that is normally accessed only by "git push" and
>>> "git pull" (or "git fetch"), the central repository model.
>>
>> pulling from it would not be a problem, I could see issues with multiple
>> pushes taking place (the underlying repository would not get corrupted, but you
>> will very quickly hit conflicts where the push is not a fast forward and you
>> need to merge, not just push)
>
> How is that different on a network file system, as opposed to using http, ssh, or git-daemon? Don't you get a "not a fast-forward" error, regardless of the protocol?
true.
>>> 2. a repository where only one user does "git add" and "git commit",
>> while
>>> other users will do "git pull", the peer-to-peer model (you pull changes
>> from
>>> me, I pull changes from you).
>>
>>
>> pulling from a shared repository is probably safe, but I wouldn't bet
>> against
>> there being any conditions where a pull at the same time someone is doing
>> an
>> update being able to cause problems.
>
> Why do you think there would be a problem?
>
>> The normal thing is to do the pulls through git-daemon, and that does make
>> sure
>> that what you are pulling is consistant.
>
> What does "git pull" via git-daemon do to ensure consistency that is different from "git pull" on a network file system?
git pull via the daemon looks at what tree items you have on each end, and then
it sends you the items needed to make you match the server. If there are partial
updates on the server (due to some update in process) the daemon should not see
that, but if you are grabbing the files directly, I would be less confident that
you are always safe.
you may _be_ safe, and if others who really know the internals speak up, take
their word on it. But, absent assurances that we know that everything is done in
the right order in the face of a networked filesystem (which may break
visibility of changes due to caching), I would not trust such raw access for
updates at all, and only somewhat trust it for read-only use.
David Lang
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Jeff King @ 2013-01-17 3:11 UTC (permalink / raw)
To: Chris Rorvick
Cc: Junio C Hamano, Max Horn, git, Angelo Borsotti, Drew Northup,
Michael Haggerty, Philip Oakley, Johannes Sixt, Kacper Kornet,
Felipe Contreras
In-Reply-To: <CAEUsAPY8T9TYCrZLWB-0Mwae_NtnqqVvGwY+4jGfqh5Lh3=Dgw@mail.gmail.com>
On Wed, Jan 16, 2013 at 08:19:28PM -0600, Chris Rorvick wrote:
> On Wed, Jan 16, 2013 at 11:43 AM, Jeff King <peff@peff.net> wrote:
> > I think that is a reasonable rule that could be applied across all parts
> > of the namespace hierarchy. And it could be applied by the client,
> > because all you need to know is whether ref->old_sha1 is reachable from
> > ref->new_sha1.
>
> is_forwardable() did solve a UI issue. Previously all instances where
> old is not reachable by new were assumed to be addressable with a
> merge. is_forwardable() attempted to determine if the concept of
> forwarding made sense given the inputs. For example, if old is a blob
> it is useless to suggest merging it.
I think it makes sense to mark such a case as different from a regular
non-fast-forward (because "git pull" is not the right advice), but:
1. is_forwardable should assume a missing object is a commit not to
regress the common case; otherwise we do not show the pull advice
when we probably should, and most of the time it is going to be a
commit
2. When we know that we are not working with commits, I am not sure
that "already exists" is the right advice to give for such a case.
It is neither "this tag already exists, so we do not update it",
nor is it strictly "cannot fast forward this commit", but rather
something else.
The expanded definition of "what is a fast forward" that I
suggested would let this fall naturally between the two.
-Peff
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Chris Rorvick @ 2013-01-17 3:42 UTC (permalink / raw)
To: Jeff King
Cc: Junio C Hamano, Max Horn, git, Angelo Borsotti, Drew Northup,
Michael Haggerty, Philip Oakley, Johannes Sixt, Kacper Kornet,
Felipe Contreras
In-Reply-To: <20130117031100.GA7264@sigill.intra.peff.net>
On Wed, Jan 16, 2013 at 9:11 PM, Jeff King <peff@peff.net> wrote:
>> is_forwardable() did solve a UI issue. Previously all instances where
>> old is not reachable by new were assumed to be addressable with a
>> merge. is_forwardable() attempted to determine if the concept of
>> forwarding made sense given the inputs. For example, if old is a blob
>> it is useless to suggest merging it.
>
> I think it makes sense to mark such a case as different from a regular
> non-fast-forward (because "git pull" is not the right advice), but:
>
> 1. is_forwardable should assume a missing object is a commit not to
> regress the common case; otherwise we do not show the pull advice
> when we probably should, and most of the time it is going to be a
> commit
Yes, obviously this was a bug, thus the use of "attempted" above. It
would have been better to assume a missing 'old' was potentially
forwardable to present the user with the most helpful advice.
> 2. When we know that we are not working with commits, I am not sure
> that "already exists" is the right advice to give for such a case.
> It is neither "this tag already exists, so we do not update it",
> nor is it strictly "cannot fast forward this commit", but rather
> something else.
But the reference already existing in the remote is a substantial
reason for not allowing the push in all of these cases. You can break
this out further if you like to explain why the specific reference
shouldn't be moved on the remote, but this is even more complicated a
simple "is old reachable from new?" test.
Chris
^ permalink raw reply
* Re: [PATCH v2 07/14] imap-send.c: inline imap_parse_list() in imap_list()
From: Michael Haggerty @ 2013-01-17 4:43 UTC (permalink / raw)
To: Junio C Hamano; +Cc: Matt Kraai, git, Jonathan Nieder
In-Reply-To: <7vip6xywdf.fsf@alter.siamese.dyndns.org>
On 01/16/2013 04:34 PM, Junio C Hamano wrote:
> Michael Haggerty <mhagger@alum.mit.edu> writes:
>
>> On 01/15/2013 07:51 PM, Matt Kraai wrote:
>>> On Tue, Jan 15, 2013 at 09:06:25AM +0100, Michael Haggerty wrote:
>>>> -static struct imap_list *parse_imap_list(struct imap *imap, char **sp)
>>>> +static struct imap_list *parse_list(char **sp)
>>>
>>> The commit subject refers to imap_parse_list and imap_list whereas the
>>> code refers to parse_imap_list and parse_list.
>>
>> Yes, you're right. Thanks.
>
> I think I've fixed this (and some other minor points in other
> patches in the series) while queuing; please check master..3691031c
> after fetching from me.
Looks good. Thanks.
Michael
--
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/
^ permalink raw reply
* Re: Question re. git remote repository
From: Matt Seitz @ 2013-01-17 5:20 UTC (permalink / raw)
To: git@vger.kernel.org; +Cc: david@lang.hm, 'matseitz@cisco.com'
"David Lang" <david@lang.hm> wrote in message news:<alpine.DEB.2.02.1301161843390.21503@nftneq.ynat.uz>...
> >>
> >> On Thu, 17 Jan 2013, Matt Seitz (matseitz) wrote:
> >>
> >>> 2. a repository where only one user does "git add" and "git commit",
> >> while other users will do "git pull", the peer-to-peer model (you pull changes
> >> from me, I pull changes from you).
> >>
>
> you may _be_ safe, and if others who really know the internals speak up, take
> their word on it.
Well, we already have Linus's article. I guess the question is whether the use case I describe above falls under:
A. "maintenance operations"
B. "normal git workflow"
Personally, I would consider this use case to be a "normal git workflow".
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Chris Rorvick @ 2013-01-17 6:20 UTC (permalink / raw)
To: Junio C Hamano
Cc: Max Horn, git, Angelo Borsotti, Drew Northup, Michael Haggerty,
Philip Oakley, Johannes Sixt, Kacper Kornet, Jeff King,
Felipe Contreras
In-Reply-To: <7vobgpxeel.fsf@alter.siamese.dyndns.org>
On Wed, Jan 16, 2013 at 10:48 AM, Junio C Hamano <gitster@pobox.com> wrote:
> It is fine when pushing into "refs/tags/" hierarchy. It is *NOT*
> OK if the type check does not satisfy this function. In that case,
> we do not actually see the existence of the destination as a
> problem, but it is reported as such. We are blocking because we do
> not like the type of the new object or the type of the old object.
> If the destination points at a commit, the push can succeed if the
> user changes what object to push, so saying "you cannot push because
> the destination already exists" is just wrong in such a case.
So the solution is to revert back to recommending a merge?
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Junio C Hamano @ 2013-01-17 6:59 UTC (permalink / raw)
To: Chris Rorvick
Cc: Max Horn, git, Angelo Borsotti, Drew Northup, Michael Haggerty,
Philip Oakley, Johannes Sixt, Kacper Kornet, Jeff King,
Felipe Contreras
In-Reply-To: <CAEUsAPb0Zg0x78e+12NqXA4PRBkOUO89KTgxtwxujS1KOx9NYg@mail.gmail.com>
Chris Rorvick <chris@rorvick.com> writes:
> On Wed, Jan 16, 2013 at 10:48 AM, Junio C Hamano <gitster@pobox.com> wrote:
>> It is fine when pushing into "refs/tags/" hierarchy. It is *NOT*
>> OK if the type check does not satisfy this function. In that case,
>> we do not actually see the existence of the destination as a
>> problem, but it is reported as such. We are blocking because we do
>> not like the type of the new object or the type of the old object.
>> If the destination points at a commit, the push can succeed if the
>> user changes what object to push, so saying "you cannot push because
>> the destination already exists" is just wrong in such a case.
>
> So the solution is to revert back to recommending a merge?
Of course not, because at that point you may not even have what you
were attempting to overwrite. Nobody says it is even something you
could merge.
The recommended solution certainly will involve a "fetch" (not
"pull" or "pull --rebase"). You fetch from over there to check what
you were about to overwrite, examine the situation to decide what
the appropriate action is.
The point is that Git in general, and the codepath that was touched
by the patch in particular, does not have enough information to
decide what the appropriate action is for the user, especially when
the ref is outside the ones we know what the conventional uses of
them are. We can make policy decisions like "tags are meant to be
unmoving anchor points, so it is unusual to overwrite any old with
any new", "heads are meant to be branch tips, and because rewinding
them while more than one repositories are working with them will
cause issues to other repositories, it is unusual to push a
non-fast-forward" and enforcement mechanism for such policy
decisions will help users, but that is only because we know what
their uses are.
The immediate action we should take is to get closer to the original
behaviour of not complaining with "ref already exists", which is
nonsensical. That does not mean that we will forbid improving the
codepath by giving different advices depending on the case.
One of the new advices could tell them to "fetch it and inspect the
situation", if old is not something we do not even have (hence we
cannot check its type, let alone the ancestry relationship of it
with new), for example.
^ permalink raw reply
* Re: [PATCH] fix some clang warnings
From: John Keeping @ 2013-01-17 10:24 UTC (permalink / raw)
To: Jeff King; +Cc: Max Horn, Antoine Pelisse, Junio C Hamano, git, Johannes Sixt
In-Reply-To: <20130116190137.GD2476@farnsworth.metanate.com>
On Wed, Jan 16, 2013 at 07:01:37PM +0000, John Keeping wrote:
> On Wed, Jan 16, 2013 at 10:24:49AM -0800, Jeff King wrote:
> > On Wed, Jan 16, 2013 at 06:22:40PM +0000, John Keeping wrote:
> >
> > Thanks for checking. I'd rather squelch the warning completely (as in my
> > re-post of Max's patch from a few minutes ago), and we can loosen it
> > (possibly with a version check) later when a fix is widely disseminated.
>
> I checked again with a trunk build of clang and the warning's still
> there, so I've created a clang bug [1] to see if they will change the
> behaviour.
>
> [1] http://llvm.org/bugs/show_bug.cgi?id=14968
Well, that was quick! This warning is now gone when using a fresh trunk
build of clang.
>From [2], it looks like this will become version 3.3 (in about 5
months). So should we change the condition to:
#if defined(__GNUC__) && (!defined(__clang__) ||
__clang_major__ > 3 || \
(__clang__major == 3 && __clang_minor__ >= 3)
[2] http://llvm.org/docs/HowToReleaseLLVM.html
John
^ permalink raw reply
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