* 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
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: Antoine Pelisse @ 2013-01-17 10:32 UTC (permalink / raw)
To: John Keeping, Max Horn
Cc: git, Johannes Sixt, Junio C Hamano, Antoine Pelisse
In-Reply-To: <1358376443-7404-2-git-send-email-apelisse@gmail.com>
John, could you confirm that you trigger the -Wtautological-compare
warning with your version of clang ?
And that this patch makes clang compilation warning-free (with the
very latest clang) ?
Cheers,
On Wed, Jan 16, 2013 at 11:47 PM, Antoine Pelisse <apelisse@gmail.com> wrote:
> Create a GREP_HEADER_FIELD_MIN so we can check that the field value is
> sane and silent the clang warning.
>
> Clang warning happens because the enum is unsigned (this is
> implementation-defined, and there is no negative fields) and the check
> is then tautological.
>
> Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
> ---
> I tried to consider discussion [1] and this [2] discussion on clang's list
>
> With these two patches and the patch from Max Horne, I'm finally able to
> compile with CC=clang CFLAGS=-Werror.
>
> [1]: http://thread.gmane.org/gmane.comp.version-control.git/184908
> [2]: http://clang-developers.42468.n3.nabble.com/Possibly-invalid-enum-tautology-warning-td3233140.html
>
> grep.c | 3 ++-
> grep.h | 3 ++-
> 2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/grep.c b/grep.c
> index 4bd1b8b..bb548ca 100644
> --- a/grep.c
> +++ b/grep.c
> @@ -625,7 +625,8 @@ static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
> for (p = opt->header_list; p; p = p->next) {
> if (p->token != GREP_PATTERN_HEAD)
> die("bug: a non-header pattern in grep header list.");
> - if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
> + if (p->field < GREP_HEADER_FIELD_MIN ||
> + GREP_HEADER_FIELD_MAX <= p->field)
> die("bug: unknown header field %d", p->field);
> compile_regexp(p, opt);
> }
> diff --git a/grep.h b/grep.h
> index 8fc854f..e4a1df5 100644
> --- a/grep.h
> +++ b/grep.h
> @@ -28,7 +28,8 @@ enum grep_context {
> };
>
> enum grep_header_field {
> - GREP_HEADER_AUTHOR = 0,
> + GREP_HEADER_FIELD_MIN = 0,
> + GREP_HEADER_AUTHOR = GREP_HEADER_FIELD_MIN,
> GREP_HEADER_COMMITTER,
> GREP_HEADER_REFLOG,
>
> --
> 1.8.1.1.435.g20d29be.dirty
>
^ permalink raw reply
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: John Keeping @ 2013-01-17 11:00 UTC (permalink / raw)
To: Antoine Pelisse; +Cc: Max Horn, git, Johannes Sixt, Junio C Hamano
In-Reply-To: <CALWbr2wk+78zxGKCo-hCOwMuMOzdGspYvMu7PA6o0OYM3Y3m4A@mail.gmail.com>
On Thu, Jan 17, 2013 at 11:32:39AM +0100, Antoine Pelisse wrote:
> John, could you confirm that you trigger the -Wtautological-compare
> warning with your version of clang ?
Yes, the warning is still there with both 3.2 and a recent trunk build
but this patch squelches it.
> And that this patch makes clang compilation warning-free (with the
> very latest clang) ?
There is one remaining warning on pu which hasn't been discussed in this
thread as far as I can see. I'll send a patch shortly.
There's also a warning that triggers with clang 3.2 but not clang trunk, which
I think is a legitimate warning - perhaps someone who understands integer type
promotion better than me can explain why the code is OK (patch->score is
declared as 'int'):
builtin/apply.c:1044:47: warning: comparison of constant 18446744073709551615
with expression of type 'int' is always false
[-Wtautological-constant-out-of-range-compare]
if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
> On Wed, Jan 16, 2013 at 11:47 PM, Antoine Pelisse <apelisse@gmail.com> wrote:
> > Create a GREP_HEADER_FIELD_MIN so we can check that the field value is
> > sane and silent the clang warning.
> >
> > Clang warning happens because the enum is unsigned (this is
> > implementation-defined, and there is no negative fields) and the check
> > is then tautological.
> >
> > Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
> > ---
> > I tried to consider discussion [1] and this [2] discussion on clang's list
> >
> > With these two patches and the patch from Max Horne, I'm finally able to
> > compile with CC=clang CFLAGS=-Werror.
> >
> > [1]: http://thread.gmane.org/gmane.comp.version-control.git/184908
> > [2]: http://clang-developers.42468.n3.nabble.com/Possibly-invalid-enum-tautology-warning-td3233140.html
> >
> > grep.c | 3 ++-
> > grep.h | 3 ++-
> > 2 files changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/grep.c b/grep.c
> > index 4bd1b8b..bb548ca 100644
> > --- a/grep.c
> > +++ b/grep.c
> > @@ -625,7 +625,8 @@ static struct grep_expr *prep_header_patterns(struct grep_opt *opt)
> > for (p = opt->header_list; p; p = p->next) {
> > if (p->token != GREP_PATTERN_HEAD)
> > die("bug: a non-header pattern in grep header list.");
> > - if (p->field < 0 || GREP_HEADER_FIELD_MAX <= p->field)
> > + if (p->field < GREP_HEADER_FIELD_MIN ||
> > + GREP_HEADER_FIELD_MAX <= p->field)
> > die("bug: unknown header field %d", p->field);
> > compile_regexp(p, opt);
> > }
> > diff --git a/grep.h b/grep.h
> > index 8fc854f..e4a1df5 100644
> > --- a/grep.h
> > +++ b/grep.h
> > @@ -28,7 +28,8 @@ enum grep_context {
> > };
> >
> > enum grep_header_field {
> > - GREP_HEADER_AUTHOR = 0,
> > + GREP_HEADER_FIELD_MIN = 0,
> > + GREP_HEADER_AUTHOR = GREP_HEADER_FIELD_MIN,
> > GREP_HEADER_COMMITTER,
> > GREP_HEADER_REFLOG,
> >
> > --
> > 1.8.1.1.435.g20d29be.dirty
> >
^ permalink raw reply
* [PATCH] combine-diff: suppress a clang warning
From: John Keeping @ 2013-01-17 11:23 UTC (permalink / raw)
To: Antoine Pelisse; +Cc: Max Horn, git, Johannes Sixt, Junio C Hamano
In-Reply-To: <20130117110008.GD4574@serenity.lan>
When compiling combine-diff.c, clang 3.2 says:
combine-diff.c:1006:19: warning: adding 'int' to a string does not
append to the string [-Wstring-plus-int]
prefix = COLONS + offset;
~~~~~~~^~~~~~~~
combine-diff.c:1006:19: note: use array indexing to silence this warning
prefix = COLONS + offset;
^
& [ ]
Suppress this by making the suggested change.
Signed-off-by: John Keeping <john@keeping.me.uk>
---
On Thu, Jan 17, 2013 at 11:00:08AM +0000, John Keeping wrote:
> On Thu, Jan 17, 2013 at 11:32:39AM +0100, Antoine Pelisse wrote:
> There is one remaining warning on pu which hasn't been discussed in this
> thread as far as I can see. I'll send a patch shortly.
... and here it is.
combine-diff.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/combine-diff.c b/combine-diff.c
index bb1cc96..dba4748 100644
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -1003,7 +1003,7 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
offset = strlen(COLONS) - num_parent;
if (offset < 0)
offset = 0;
- prefix = COLONS + offset;
+ prefix = &COLONS[offset];
/* Show the modes */
for (i = 0; i < num_parent; i++) {
--
1.8.1
^ permalink raw reply related
* Re: GIT get corrupted on lustre
From: Eric Chamberland @ 2013-01-17 13:07 UTC (permalink / raw)
To: git; +Cc: Maxime Boissonneault, Sébastien Boisvert
In-Reply-To: <50EDDF12.3080800@giref.ulaval.ca>
Hi!
I still have the corruption problems....
We just compiled a git without threads to try... (by the way,
--without-pthreads doesn't work, you have to do a --disable-pthreads
instead).
And to remove the warnings about threads at "git gc" execution, I did a:
git config --local pack.threads 1
and cloned a repository and started to do:
git gc
once every hour.
Then this night (at 05:35:02 exactly), the same error as usual occurred:
error: index file
.git/objects/pack/pack-bf0748cee64a1964be0a1061c82aca51c993b825.idx is
too small
error: refs/heads/master does not point to a valid object!
So now I am convinced that it is not a thread problem....
I am kind of discouraged, we like to use git, but in this case we have
this error which seems unsolvable!
Anyone has a new idea?
Thanks,
Eric
On 01/09/2013 04:20 PM, Eric Chamberland wrote:
> Hi Brian,
>
> On 01/08/2013 11:11 AM, Eric Chamberland wrote:
>> On 12/24/2012 10:11 AM, Brian J. Murrell wrote:
>>> Have you tried adding a "-q" to the git command line to quiet down git's
>>> "feedback" messages?
>>>
>>
>
> I moved to git 1.8.1 and added the "-q" to the command "git gc" but it
> occured to return an error, so the "-q" option is not avoiding the
> problem here... :-/
>
> command in crontab:
>
> cd /rap/jsf-051-aa/ericc/tests_git_clones/GIREF && for i in seq 10; do
> /software/apps/git/1.8.1/bin/git gc -q || true;done
>
> results:
> error: index file
> .git/objects/pack/pack-1f09879c88cd71a15dcc891713cf038d249830ad.idx is
> too small
> error: refs/remotes/origin/BIB_Branche_1_4_x does not point to a valid
> object!
>
> and this clone was a "clean" clone in which only "git qc -q" has been
> run on....
>
> I still have a doubt on threads....
>
> Eric
>
> --
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply
* Re: [PATCH v6 0/8] push: update remote tags only with force
From: Chris Rorvick @ 2013-01-17 13:09 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: <7vehhkuwg5.fsf@alter.siamese.dyndns.org>
On Thu, Jan 17, 2013 at 12:59 AM, Junio C Hamano <gitster@pobox.com> wrote:
> 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.
I was referring to your concern about rejecting based on type. A push
causing a reference to move (for example) from a commit to a blob is
rejected as "already exists" with this patch. You emphatically state
this is not OK and your solution is to revert back to behavior that
advises a merge.
Clearly the bug regarding an 'old' unknown to the client should be
fixed. This is a obvious test case I should have covered and it's
unfortunate it made it into master. But I don't understand why
is_forwardable() was misguided (maybe poorly named) nor why
ref_newer() is a better place to solve the issues it was addressing.
Chris
^ permalink raw reply
* merge vs. rebase question
From: Dennis Putnam @ 2013-01-17 14:14 UTC (permalink / raw)
To: git@vger.kernel.org
[-- Attachment #1: Type: text/plain, Size: 955 bytes --]
As a git noob I am having trouble understanding when to use which
commands. I have a repository (bare) on my Linux server. I also created
a build directory as a local repository. In my build script I do a 'git
pull' to make sure the build directory is up to date. No changes are
made to my source so this repository never does an 'add' or 'commit'.
When I run my script with 'pull', the output indicates that changes were
found and seems to have pulled them into the local directory. However,
when I look at the resulting source, none of the expected changes show
up. I then tried a 'fetch' and 'rebase'. That worked but I don't
understand why. I thought 'pull' did a 'fetch' and a 'merge' so I don't
understand why a 'fetch' and 'rebase' worked but 'fetch' and 'merge' did
not. Unless my understanding of what 'pull' does is wrong. In my case,
what should I be using in my script to assure that the build directory
is current?
Thanks.
[-- Attachment #2: OpenPGP digital signature --]
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^ permalink raw reply
* Re: GIT get corrupted on lustre
From: Philippe Vaucher @ 2013-01-17 14:23 UTC (permalink / raw)
To: Eric Chamberland
Cc: git@vger.kernel.org, Maxime Boissonneault,
Sébastien Boisvert
In-Reply-To: <50F7F793.80507@giref.ulaval.ca>
> Anyone has a new idea?
Did you try Jeff King's code to confirm his idea?
Philippe
^ permalink raw reply
* Re: GIT get corrupted on lustre
From: Eric Chamberland @ 2013-01-17 16:30 UTC (permalink / raw)
To: Philippe Vaucher
Cc: git@vger.kernel.org, Maxime Boissonneault,
Sébastien Boisvert
In-Reply-To: <CAGK7Mr4R=OwfWt4Kat75C8YDi3iLTavMLxeoLxkf1-gKhxrucg@mail.gmail.com>
On 01/17/2013 09:23 AM, Philippe Vaucher wrote:
>> Anyone has a new idea?
>
> Did you try Jeff King's code to confirm his idea?
>
> Philippe
>
Yes I did, but it was running without any problem....
I find that my test case is "simple" (fresh git clone then "git gc" in a
crontab), I bet anyone who has access to a Lustre filesystem can
reproduce the problem... The problem is to have such a filesystem to do
the tests....
But I am available to do it...
Thanks,
Eric
^ permalink raw reply
* RE: GIT get corrupted on lustre
From: Pyeron, Jason J CTR (US) @ 2013-01-17 16:40 UTC (permalink / raw)
To: Eric Chamberland, Philippe Vaucher
Cc: git@vger.kernel.org, Maxime Boissonneault,
Sébastien Boisvert
In-Reply-To: <50F8273E.5050803@giref.ulaval.ca>
[-- Attachment #1: Type: text/plain, Size: 728 bytes --]
> -----Original Message-----
> From: Eric Chamberland
> Sent: Thursday, January 17, 2013 11:31 AM
>
> On 01/17/2013 09:23 AM, Philippe Vaucher wrote:
> >> Anyone has a new idea?
> >
> > Did you try Jeff King's code to confirm his idea?
> >
> > Philippe
> >
>
> Yes I did, but it was running without any problem....
>
> I find that my test case is "simple" (fresh git clone then "git gc" in
> a
> crontab), I bet anyone who has access to a Lustre filesystem can
> reproduce the problem... The problem is to have such a filesystem to
> do
> the tests....
Stabbing in the dark, but can you log the details with ProcessMon?
http://technet.microsoft.com/en-us/sysinternals/bb896645
>
> But I am available to do it...
-Jason
[-- Attachment #2: smime.p7s --]
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^ permalink raw reply
* Re: GIT get corrupted on lustre
From: Maxime Boissonneault @ 2013-01-17 16:41 UTC (permalink / raw)
To: Pyeron, Jason J CTR (US)
Cc: Eric Chamberland, Philippe Vaucher, git@vger.kernel.org,
Sébastien Boisvert
In-Reply-To: <871B6C10EBEFE342A772D1159D1320853A042AD7@umechphj.easf.csd.disa.mil>
I don't know of any lustre filesystem that is used on Windows. Barely
anybody uses Windows in the HPC industry.
This is a Linux cluster.
Maxime Boissonneault
Le 2013-01-17 11:40, Pyeron, Jason J CTR (US) a écrit :
>> -----Original Message-----
>> From: Eric Chamberland
>> Sent: Thursday, January 17, 2013 11:31 AM
>>
>> On 01/17/2013 09:23 AM, Philippe Vaucher wrote:
>>>> Anyone has a new idea?
>>> Did you try Jeff King's code to confirm his idea?
>>>
>>> Philippe
>>>
>> Yes I did, but it was running without any problem....
>>
>> I find that my test case is "simple" (fresh git clone then "git gc" in
>> a
>> crontab), I bet anyone who has access to a Lustre filesystem can
>> reproduce the problem... The problem is to have such a filesystem to
>> do
>> the tests....
> Stabbing in the dark, but can you log the details with ProcessMon?
>
> http://technet.microsoft.com/en-us/sysinternals/bb896645
>
>> But I am available to do it...
> -Jason
--
---------------------------------
Maxime Boissonneault
Analyste de calcul - Calcul Québec, Université Laval
Ph. D. en physique
^ permalink raw reply
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: Linus Torvalds @ 2013-01-17 16:44 UTC (permalink / raw)
To: John Keeping
Cc: Antoine Pelisse, Max Horn, git, Johannes Sixt, Junio C Hamano
In-Reply-To: <20130117110008.GD4574@serenity.lan>
On Thu, Jan 17, 2013 at 3:00 AM, John Keeping <john@keeping.me.uk> wrote:
>
> There's also a warning that triggers with clang 3.2 but not clang trunk, which
> I think is a legitimate warning - perhaps someone who understands integer type
> promotion better than me can explain why the code is OK (patch->score is
> declared as 'int'):
>
> builtin/apply.c:1044:47: warning: comparison of constant 18446744073709551615
> with expression of type 'int' is always false
> [-Wtautological-constant-out-of-range-compare]
> if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
The warning seems to be very very wrong, and implies that clang has
some nasty bug in it.
Since patch->score is 'int', and UNLONG_MAX is 'unsigned long', the
conversion rules for the comparison is that the int result from the
assignment is cast to unsigned long. And if you cast (int)-1 to
unsigned long, you *do* get ULONG_MAX. That's true regardless of
whether "long" has the same number of bits as "int" or is bigger. The
implicit cast will be done as a sign-extension (unsigned long is not
signed, but the source type of 'int' *is* signed, and that is what
determines the sign extension on casting).
So the "is always false" is pure and utter crap. clang is wrong, and
it is wrong in a way that implies that it actually generates incorrect
code. It may well be worth making a clang bug report about this.
That said, clang is certainly understandably confused. The code
depends on subtle conversion rules and bit patterns, and is clearly
very confusingly written.
So it would probably be good to rewrite it as
unsigned long val = strtoul(line, NULL, 10);
if (val == ULONG_MAX) ..
patch->score = val;
instead. At which point you might as well make the comparison be ">=
INT_MAX" instead, since anything bigger than that is going to be
bogus.
So the git code is probably worth cleaning up, but for git it would be
a cleanup. For clang, this implies a major bug and bad code
generation.
Linus
Linus
^ permalink raw reply
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: Antoine Pelisse @ 2013-01-17 16:56 UTC (permalink / raw)
To: John Keeping, Linus Torvalds; +Cc: Max Horn, git, Johannes Sixt, Junio C Hamano
In-Reply-To: <CA+55aFxYSX2iYPSafKdCDSfWSMfQxP3R3Hqh8GuiiR6EbWfk3w@mail.gmail.com>
BTW, I think it has been addressed [1] by clang already and that would
explain why you don't have the warning when using clang trunk version.
[1]: http://llvm-reviews.chandlerc.com/D113
Antoine,
On Thu, Jan 17, 2013 at 5:44 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Thu, Jan 17, 2013 at 3:00 AM, John Keeping <john@keeping.me.uk> wrote:
>>
>> There's also a warning that triggers with clang 3.2 but not clang trunk, which
>> I think is a legitimate warning - perhaps someone who understands integer type
>> promotion better than me can explain why the code is OK (patch->score is
>> declared as 'int'):
>>
>> builtin/apply.c:1044:47: warning: comparison of constant 18446744073709551615
>> with expression of type 'int' is always false
>> [-Wtautological-constant-out-of-range-compare]
>> if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
>
> The warning seems to be very very wrong, and implies that clang has
> some nasty bug in it.
>
> Since patch->score is 'int', and UNLONG_MAX is 'unsigned long', the
> conversion rules for the comparison is that the int result from the
> assignment is cast to unsigned long. And if you cast (int)-1 to
> unsigned long, you *do* get ULONG_MAX. That's true regardless of
> whether "long" has the same number of bits as "int" or is bigger. The
> implicit cast will be done as a sign-extension (unsigned long is not
> signed, but the source type of 'int' *is* signed, and that is what
> determines the sign extension on casting).
>
> So the "is always false" is pure and utter crap. clang is wrong, and
> it is wrong in a way that implies that it actually generates incorrect
> code. It may well be worth making a clang bug report about this.
>
> That said, clang is certainly understandably confused. The code
> depends on subtle conversion rules and bit patterns, and is clearly
> very confusingly written.
>
> So it would probably be good to rewrite it as
>
> unsigned long val = strtoul(line, NULL, 10);
> if (val == ULONG_MAX) ..
> patch->score = val;
>
> instead. At which point you might as well make the comparison be ">=
> INT_MAX" instead, since anything bigger than that is going to be
> bogus.
>
> So the git code is probably worth cleaning up, but for git it would be
> a cleanup. For clang, this implies a major bug and bad code
> generation.
>
> Linus
> Linus
^ permalink raw reply
* Re: [PATCH 2/2] fix clang -Wtautological-compare with unsigned enum
From: John Keeping @ 2013-01-17 17:02 UTC (permalink / raw)
To: Linus Torvalds
Cc: Antoine Pelisse, Max Horn, git, Johannes Sixt, Junio C Hamano
In-Reply-To: <CA+55aFxYSX2iYPSafKdCDSfWSMfQxP3R3Hqh8GuiiR6EbWfk3w@mail.gmail.com>
On Thu, Jan 17, 2013 at 08:44:20AM -0800, Linus Torvalds wrote:
> On Thu, Jan 17, 2013 at 3:00 AM, John Keeping <john@keeping.me.uk> wrote:
>>
>> There's also a warning that triggers with clang 3.2 but not clang trunk, which
>> I think is a legitimate warning - perhaps someone who understands integer type
>> promotion better than me can explain why the code is OK (patch->score is
>> declared as 'int'):
>>
>> builtin/apply.c:1044:47: warning: comparison of constant 18446744073709551615
>> with expression of type 'int' is always false
>> [-Wtautological-constant-out-of-range-compare]
>> if ((patch->score = strtoul(line, NULL, 10)) == ULONG_MAX)
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~
>
> The warning seems to be very very wrong, and implies that clang has
> some nasty bug in it.
>
> Since patch->score is 'int', and UNLONG_MAX is 'unsigned long', the
> conversion rules for the comparison is that the int result from the
> assignment is cast to unsigned long. And if you cast (int)-1 to
> unsigned long, you *do* get ULONG_MAX. That's true regardless of
> whether "long" has the same number of bits as "int" or is bigger. The
> implicit cast will be done as a sign-extension (unsigned long is not
> signed, but the source type of 'int' *is* signed, and that is what
> determines the sign extension on casting).
>
> So the "is always false" is pure and utter crap. clang is wrong, and
> it is wrong in a way that implies that it actually generates incorrect
> code. It may well be worth making a clang bug report about this.
The warning doesn't occur with a build from their trunk so it looks like
it's already fixed - it just won't make into into a release for about 5
months going by their timeline.
Thanks for the clear explanation.
^ permalink raw reply
* RE: GIT get corrupted on lustre
From: Pyeron, Jason J CTR (US) @ 2013-01-17 17:17 UTC (permalink / raw)
To: Maxime Boissonneault
Cc: Eric Chamberland, Philippe Vaucher, git@vger.kernel.org,
Sébastien Boisvert
In-Reply-To: <50F829A9.7090606@calculquebec.ca>
[-- Attachment #1: Type: text/plain, Size: 1843 bytes --]
Sorry, I am in cygwin mode, and I had crossed wires in my head. s/ProcessMon/strace/
> -----Original Message-----
> From: git-owner@vger.kernel.org [mailto:git-owner@vger.kernel.org] On
> Behalf Of Maxime Boissonneault
> Sent: Thursday, January 17, 2013 11:41 AM
> To: Pyeron, Jason J CTR (US)
> Cc: Eric Chamberland; Philippe Vaucher; git@vger.kernel.org; Sébastien
> Boisvert
> Subject: Re: GIT get corrupted on lustre
>
> I don't know of any lustre filesystem that is used on Windows. Barely
> anybody uses Windows in the HPC industry.
> This is a Linux cluster.
>
> Maxime Boissonneault
>
> Le 2013-01-17 11:40, Pyeron, Jason J CTR (US) a écrit :
> >> -----Original Message-----
> >> From: Eric Chamberland
> >> Sent: Thursday, January 17, 2013 11:31 AM
> >>
> >> On 01/17/2013 09:23 AM, Philippe Vaucher wrote:
> >>>> Anyone has a new idea?
> >>> Did you try Jeff King's code to confirm his idea?
> >>>
> >>> Philippe
> >>>
> >> Yes I did, but it was running without any problem....
> >>
> >> I find that my test case is "simple" (fresh git clone then "git gc"
> in
> >> a
> >> crontab), I bet anyone who has access to a Lustre filesystem can
> >> reproduce the problem... The problem is to have such a filesystem
> to
> >> do
> >> the tests....
> > Stabbing in the dark, but can you log the details with ProcessMon?
> >
> > http://technet.microsoft.com/en-us/sysinternals/bb896645
> >
> >> But I am available to do it...
> > -Jason
>
>
> --
> ---------------------------------
> Maxime Boissonneault
> Analyste de calcul - Calcul Québec, Université Laval
> Ph. D. en physique
>
> --
> To unsubscribe from this list: send the line "unsubscribe git" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
[-- Attachment #2: smime.p7s --]
[-- Type: application/x-pkcs7-signature, Size: 5615 bytes --]
^ permalink raw reply
* [PATCH v2 0/8] Initial Python 3 support
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358018078.git.john@keeping.me.uk>
This series does enough so that everything except git-p4 runs under
Python 3.
As discussed with Pete, it may not make sense to change git-p4 to
support Python 3 until Perforce's Python output mode is changed. So
does it make sense to merge this now and say "use Python 2 if you want
git-p4"?
Changes since v1:
* rebased on master after fc/remote-testgit-feature-done was merged,
leading to an extra change in patch 8 (git-remote-testpy: call print
as a function)
* changed patch 2 (git_remote_helpers: fix input when running under
Python 3) to treat ref names as byte strings
John Keeping (8):
git_remote_helpers: Allow building with Python 3
git_remote_helpers: fix input when running under Python 3
git_remote_helpers: Force rebuild if python version changes
git_remote_helpers: Use 2to3 if building with Python 3
svn-fe: allow svnrdump_sim.py to run with Python 3
git-remote-testpy: hash bytes explicitly
git-remote-testpy: don't do unbuffered text I/O
git-remote-testpy: call print as a function
contrib/svn-fe/svnrdump_sim.py | 4 ++--
git-remote-testpy.py | 42 +++++++++++++++++++-------------------
git_remote_helpers/.gitignore | 1 +
git_remote_helpers/Makefile | 10 +++++++--
git_remote_helpers/git/importer.py | 9 +++++---
git_remote_helpers/setup.py | 10 +++++++++
6 files changed, 48 insertions(+), 28 deletions(-)
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply
* [PATCH v2 1/8] git_remote_helpers: allow building with Python 3
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
Change inline Python to call "print" as a function not a statement.
This is harmless because Python 2 will see the parentheses as redundant
grouping but they are necessary to run this code with Python 3.
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git_remote_helpers/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/git_remote_helpers/Makefile b/git_remote_helpers/Makefile
index 74b05dc..f65f064 100644
--- a/git_remote_helpers/Makefile
+++ b/git_remote_helpers/Makefile
@@ -23,7 +23,7 @@ endif
PYLIBDIR=$(shell $(PYTHON_PATH) -c \
"import sys; \
- print 'lib/python%i.%i/site-packages' % sys.version_info[:2]")
+ print('lib/python%i.%i/site-packages' % sys.version_info[:2])")
all: $(pysetupfile)
$(QUIET)$(PYTHON_PATH) $(pysetupfile) $(QUIETSETUP) build
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 2/8] git_remote_helpers: fix input when running under Python 3
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
Although 2to3 will fix most issues in Python 2 code to make it run under
Python 3, it does not handle the new strict separation between byte
strings and unicode strings. There is one instance in
git_remote_helpers where we are caught by this, which is when reading
refs from "git for-each-ref".
Fix this by operating on the returned string as a byte string rather
than a unicode string. As this method is currently only used internally
by the class this does not affect code anywhere else.
Note that we cannot use byte strings in the source as the 'b' prefix is
not supported before Python 2.7 so in order to maintain compatibility
with the maximum range of Python versions we use an explicit call to
encode().
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git_remote_helpers/git/importer.py | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/git_remote_helpers/git/importer.py b/git_remote_helpers/git/importer.py
index e28cc8f..d3f90e1 100644
--- a/git_remote_helpers/git/importer.py
+++ b/git_remote_helpers/git/importer.py
@@ -18,13 +18,16 @@ class GitImporter(object):
def get_refs(self, gitdir):
"""Returns a dictionary with refs.
+
+ Note that the keys in the returned dictionary are byte strings as
+ read from git.
"""
args = ["git", "--git-dir=" + gitdir, "for-each-ref", "refs/heads"]
- lines = check_output(args).strip().split('\n')
+ lines = check_output(args).strip().split('\n'.encode('ascii'))
refs = {}
for line in lines:
- value, name = line.split(' ')
- name = name.strip('commit\t')
+ value, name = line.split(' '.encode('ascii'))
+ name = name.strip('commit\t'.encode('ascii'))
refs[name] = value
return refs
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 3/8] git_remote_helpers: force rebuild if python version changes
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
When different version of python are used to build via distutils, the
behaviour can change. Detect changes in version and pass --force in
this case.
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git_remote_helpers/.gitignore | 1 +
git_remote_helpers/Makefile | 8 +++++++-
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/git_remote_helpers/.gitignore b/git_remote_helpers/.gitignore
index 2247d5f..06c664f 100644
--- a/git_remote_helpers/.gitignore
+++ b/git_remote_helpers/.gitignore
@@ -1,2 +1,3 @@
+/GIT-PYTHON_VERSION
/build
/dist
diff --git a/git_remote_helpers/Makefile b/git_remote_helpers/Makefile
index f65f064..91f458f 100644
--- a/git_remote_helpers/Makefile
+++ b/git_remote_helpers/Makefile
@@ -25,8 +25,14 @@ PYLIBDIR=$(shell $(PYTHON_PATH) -c \
"import sys; \
print('lib/python%i.%i/site-packages' % sys.version_info[:2])")
+py_version=$(shell $(PYTHON_PATH) -c \
+ 'import sys; print("%i.%i" % sys.version_info[:2])')
+
all: $(pysetupfile)
- $(QUIET)$(PYTHON_PATH) $(pysetupfile) $(QUIETSETUP) build
+ $(QUIET)test "$$(cat GIT-PYTHON_VERSION 2>/dev/null)" = "$(py_version)" || \
+ flags=--force; \
+ $(PYTHON_PATH) $(pysetupfile) $(QUIETSETUP) build $$flags
+ $(QUIET)echo "$(py_version)" >GIT-PYTHON_VERSION
install: $(pysetupfile)
$(PYTHON_PATH) $(pysetupfile) install --prefix $(DESTDIR_SQ)$(prefix)
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 4/8] git_remote_helpers: use 2to3 if building with Python 3
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
Using the approach detailed on the Python wiki[1], run 2to3 on the code
as part of the build if building with Python 3.
The code itself requires no changes to convert cleanly.
[1] http://wiki.python.org/moin/PortingPythonToPy3k
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git_remote_helpers/setup.py | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/git_remote_helpers/setup.py b/git_remote_helpers/setup.py
index 4d434b6..6de41de 100644
--- a/git_remote_helpers/setup.py
+++ b/git_remote_helpers/setup.py
@@ -4,6 +4,15 @@
from distutils.core import setup
+# 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
+# Python3.
+try:
+ from distutils.command.build_py import build_py_2to3 as build_py
+except ImportError:
+ # 2.x
+ from distutils.command.build_py import build_py
+
setup(
name = 'git_remote_helpers',
version = '0.1.0',
@@ -14,4 +23,5 @@ setup(
url = 'http://www.git-scm.com/',
package_dir = {'git_remote_helpers': ''},
packages = ['git_remote_helpers', 'git_remote_helpers.git'],
+ cmdclass = {'build_py': build_py},
)
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 5/8] svn-fe: allow svnrdump_sim.py to run with Python 3
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
The changes to allow this script to run with Python 3 are minimal and do
not affect its functionality on the versions of Python 2 that are
already supported (2.4 onwards).
Signed-off-by: John Keeping <john@keeping.me.uk>
---
contrib/svn-fe/svnrdump_sim.py | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/contrib/svn-fe/svnrdump_sim.py b/contrib/svn-fe/svnrdump_sim.py
index 17cf6f9..4e78a1c 100755
--- a/contrib/svn-fe/svnrdump_sim.py
+++ b/contrib/svn-fe/svnrdump_sim.py
@@ -14,7 +14,7 @@ if sys.hexversion < 0x02040000:
def getrevlimit():
var = 'SVNRMAX'
- if os.environ.has_key(var):
+ if var in os.environ:
return os.environ[var]
return None
@@ -44,7 +44,7 @@ def writedump(url, lower, upper):
if __name__ == "__main__":
if not (len(sys.argv) in (3, 4, 5)):
- print "usage: %s dump URL -rLOWER:UPPER"
+ print("usage: %s dump URL -rLOWER:UPPER")
sys.exit(1)
if not sys.argv[1] == 'dump': raise NotImplementedError('only "dump" is suppported.')
url = sys.argv[2]
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 6/8] git-remote-testpy: hash bytes explicitly
From: John Keeping @ 2013-01-17 18:53 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
Under Python 3 'hasher.update(...)' must take a byte string and not a
unicode string. Explicitly encode the argument to this method as UTF-8
so that this code works under Python 3.
This moves the required Python version forward to 2.0.
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git-remote-testpy.py | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/git-remote-testpy.py b/git-remote-testpy.py
index d94a66a..f8dc196 100644
--- a/git-remote-testpy.py
+++ b/git-remote-testpy.py
@@ -31,9 +31,9 @@ from git_remote_helpers.git.exporter import GitExporter
from git_remote_helpers.git.importer import GitImporter
from git_remote_helpers.git.non_local import NonLocalGit
-if sys.hexversion < 0x01050200:
- # os.makedirs() is the limiter
- sys.stderr.write("git-remote-testgit: requires Python 1.5.2 or later.\n")
+if sys.hexversion < 0x02000000:
+ # string.encode() is the limiter
+ sys.stderr.write("git-remote-testgit: requires Python 2.0 or later.\n")
sys.exit(1)
def get_repo(alias, url):
@@ -45,7 +45,7 @@ def get_repo(alias, url):
repo.get_head()
hasher = _digest()
- hasher.update(repo.path)
+ hasher.update(repo.path.encode('utf-8'))
repo.hash = hasher.hexdigest()
repo.get_base_path = lambda base: os.path.join(
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 7/8] git-remote-testpy: don't do unbuffered text I/O
From: John Keeping @ 2013-01-17 18:54 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
Python 3 forbids unbuffered I/O in text mode. Change the reading of
stdin in git-remote-testpy so that we read the lines as bytes and then
decode them a line at a time.
This allows us to keep the I/O unbuffered in order to avoid
reintroducing the bug fixed by commit 7fb8e16 (git-remote-testgit: fix
race when spawning fast-import).
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git-remote-testpy.py | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/git-remote-testpy.py b/git-remote-testpy.py
index f8dc196..bc5e3cf 100644
--- a/git-remote-testpy.py
+++ b/git-remote-testpy.py
@@ -154,7 +154,7 @@ def do_import(repo, args):
refs = [ref]
while True:
- line = sys.stdin.readline()
+ line = sys.stdin.readline().decode()
if line == '\n':
break
if not line.startswith('import '):
@@ -225,7 +225,7 @@ def read_one_line(repo):
line = sys.stdin.readline()
- cmdline = line
+ cmdline = line.decode()
if not cmdline:
warn("Unexpected EOF")
@@ -277,7 +277,7 @@ def main(args):
more = True
- sys.stdin = os.fdopen(sys.stdin.fileno(), 'r', 0)
+ sys.stdin = os.fdopen(sys.stdin.fileno(), 'rb', 0)
while (more):
more = read_one_line(repo)
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* [PATCH v2 8/8] git-remote-testpy: call print as a function
From: John Keeping @ 2013-01-17 18:54 UTC (permalink / raw)
To: Junio C Hamano; +Cc: John Keeping, Michael Haggerty, git, Pete Wyckoff
In-Reply-To: <cover.1358448207.git.john@keeping.me.uk>
This is harmless in Python 2, which sees the parentheses as redundant
grouping, but is required for Python 3. Since this is the only change
required to make this script just run under Python 3 without needing
2to3 it seems worthwhile.
The case of an empty print must be handled specially because in that
case Python 2 will interpret '()' as an empty tuple and print it as
'()'; inserting an empty string fixes this.
Signed-off-by: John Keeping <john@keeping.me.uk>
---
git-remote-testpy.py | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/git-remote-testpy.py b/git-remote-testpy.py
index bc5e3cf..ccdb2dc 100644
--- a/git-remote-testpy.py
+++ b/git-remote-testpy.py
@@ -87,9 +87,9 @@ def do_capabilities(repo, args):
"""Prints the supported capabilities.
"""
- print "import"
- print "export"
- print "refspec refs/heads/*:%s*" % repo.prefix
+ print("import")
+ print("export")
+ print("refspec refs/heads/*:%s*" % repo.prefix)
dirname = repo.get_base_path(repo.gitdir)
@@ -98,11 +98,11 @@ def do_capabilities(repo, args):
path = os.path.join(dirname, 'git.marks')
- print "*export-marks %s" % path
+ print("*export-marks %s" % path)
if os.path.exists(path):
- print "*import-marks %s" % path
+ print("*import-marks %s" % path)
- print # end capabilities
+ print('') # end capabilities
def do_list(repo, args):
@@ -115,16 +115,16 @@ def do_list(repo, args):
for ref in repo.revs:
debug("? refs/heads/%s", ref)
- print "? refs/heads/%s" % ref
+ print("? refs/heads/%s" % ref)
if repo.head:
debug("@refs/heads/%s HEAD" % repo.head)
- print "@refs/heads/%s HEAD" % repo.head
+ print("@refs/heads/%s HEAD" % repo.head)
else:
debug("@refs/heads/master HEAD")
- print "@refs/heads/master HEAD"
+ print("@refs/heads/master HEAD")
- print # end list
+ print('') # end list
def update_local_repo(repo):
@@ -164,7 +164,7 @@ def do_import(repo, args):
ref = line[7:].strip()
refs.append(ref)
- print "feature done"
+ print("feature done")
if os.environ.get("GIT_REMOTE_TESTGIT_FAILURE"):
die('Told to fail')
@@ -172,7 +172,7 @@ def do_import(repo, args):
repo = update_local_repo(repo)
repo.exporter.export_repo(repo.gitdir, refs)
- print "done"
+ print("done")
def do_export(repo, args):
@@ -192,8 +192,8 @@ def do_export(repo, args):
repo.non_local.push(repo.gitdir)
for ref in changed:
- print "ok %s" % ref
- print
+ print("ok %s" % ref)
+ print('')
COMMANDS = {
--
1.8.1.1.260.g99b33f4.dirty
^ permalink raw reply related
* Re: [PATCH 2/3] Allow Git::get_tz_offset to properly handle DST boundary times
From: Junio C Hamano @ 2013-01-17 19:09 UTC (permalink / raw)
To: Ben Walton; +Cc: esr, git
In-Reply-To: <1358291405-10173-3-git-send-email-bdwalton@gmail.com>
Ben Walton <bdwalton@gmail.com> writes:
> The Git::get_tz_offset is meant to provide a workalike replacement for
> the GNU strftime %z format specifier. The algorithm used failed to
> properly handle DST boundary cases.
>
> For example, the unix time 1162105199 in CST6CDT saw set_tz_offset
> improperly return -0600 instead of -0500.
>
> TZ=CST6CDT date -d @1162105199 +"%c %z"
> Sun 29 Oct 2006 01:59:59 AM CDT -0500
>
> $ zdump -v /usr/share/zoneinfo/CST6CDT | grep 2006
> /usr/share/zoneinfo/CST6CDT Sun Apr 2 07:59:59 2006 UTC = Sun Apr 2
> 01:59:59 2006 CST isdst=0 gmtoff=-21600
> /usr/share/zoneinfo/CST6CDT Sun Apr 2 08:00:00 2006 UTC = Sun Apr 2
> 03:00:00 2006 CDT isdst=1 gmtoff=-18000
> /usr/share/zoneinfo/CST6CDT Sun Oct 29 06:59:59 2006 UTC = Sun Oct 29
> 01:59:59 2006 CDT isdst=1 gmtoff=-18000
> /usr/share/zoneinfo/CST6CDT Sun Oct 29 07:00:00 2006 UTC = Sun Oct 29
> 01:00:00 2006 CST isdst=0 gmtoff=-21600
>
> To determine how many hours/minutes away from GMT a particular time
> was, we calculated the gmtime() of the requested time value and then
> used Time::Local's timelocal() function to turn the GMT-based time
> back into a scalar value representing seconds from the epoch. Because
> GMT has no daylight savings time, timelocal() cannot handle the
> ambiguous times that occur at DST boundaries since there are two
> possible correct results.
>
> To work around the ambiguity at these boundaries, we must take into
> account the pre and post conversion values for is_dst as provided by
> both the original time value and the value that has been run through
> timelocal(). If the is_dst field of the two times disagree then we
> must modify the value returned from timelocal() by an hour in the
> correct direction.
It seems to me that it is a very roundabout way. It may be correct,
but it is unclear why the magic +/-3600 shift is the right solution
and I suspect even you wouldn't notice if I sent you back your patch
with a slight change to swap $gm += 3600 and $gm -= 3600 lines ;-).
For that timestamp in question, the human-readable representation of
gmtime($t) and localtime($t) look like these two strings:
my $t = 1162105199;
print gmtime($t), "\n"; # Sun Oct 29 06:59:59 2006
print localtime($t), "\n"; # Sun Oct 29 01:59:59 2006
As a human, you can easily see that these two stringified timestamps
look 5 hours apart. Think how you managed to do so.
If we convert these back to the seconds-since-epoch, as if these
broken-down times were both in a single timezone that does not have
any DST issues, you can get the offset (in seconds) by subtraction,
and that is essentially the same as the way in which your eyes saw
they are 5 hours apart, no? In other words, why do you need to run
timelocal() at all?
my $t = 1162105199;
my $lct = timegm(localtime($t));
# of course, timegm(gmtime($t)) == $t
my $minutes = int(($lct - $t)/60);
my $sign "+";
if ($minutes < 0) {
$sign = "-";
$minutes = -$minutes;
}
my $hours = int($minutes/60);
$minutes -= $hours * 60;
sprintf("%s%02d%02d", $sign, $hours, $minutes);
Confused...
>
> Signed-off-by: Ben Walton <bdwalton@gmail.com>
> ---
> perl/Git.pm | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/perl/Git.pm b/perl/Git.pm
> index 5649bcc..788b9b4 100644
> --- a/perl/Git.pm
> +++ b/perl/Git.pm
> @@ -528,7 +528,27 @@ If TIME is not supplied, the current local time is used.
> sub get_tz_offset {
> # some systmes don't handle or mishandle %z, so be creative.
> my $t = shift || time;
> + # timelocal() has a problem when it comes to DST ambiguity so
> + # times that are on a DST boundary cannot be properly converted
> + # using it. we will possibly adjust its result depending on whehter
> + # pre and post conversions agree on DST
> my $gm = timelocal(gmtime($t));
> +
> + # we need to know whether we were originally in DST or not
> + my $orig_dst = (localtime($t))[8];
> + # and also whether timelocal thinks we're in DST
> + my $conv_dst = (localtime($gm))[8];
> +
> + # re-adjust $gm based on the DST value for the two times we're
> + # handling.
> + if ($orig_dst != $conv_dst) {
> + if ($orig_dst == 1) {
> + $gm -= 3600;
> + } else {
> + $gm += 3600;
> + }
> + }
> +
> my $sign = qw( + + - )[ $t <=> $gm ];
> return sprintf("%s%02d%02d", $sign, (gmtime(abs($t - $gm)))[2,1]);
> }
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