Error when cloning with weird local directory

Error when cloning with weird local directory

[Chris Packham]

Hi All,

A developer at $dayjob called me over to have a look at a git error he
was getting (names changed to protect the innocent).

  $ git --version
  git version 2.5.0
  $ git clone ssh://example.com/repo.git
  Cloning into 'repo'...
  fatal: I don't handle protocol '/home/user/src/ssh'

After a bit of head scratching we found that he had a local directory
structure called 'ssh://example.com/repo.git' it wasn't a complete
repo but it had some of the things one expects to find in a .git
directory (info, objects, refs, etc). It had been there for a while
and we suspect was created by a scp gone wrong from the last time he
was dealing with repo.git.

I'm wondering if it's worth catching this kind of weirdness and
erroring out with a slightly more useful message. I'm also wondering
what would have happened if this repo was actually a full and complete
thing.

I'm not sure that there is a problem worth solving here. I can provide
an anonymized tarball of the directory structure in question if anyone
is interested. But maybe this is useful for future mailing list
searchers[1].

Thanks,
Chris
--
[1] - https://xkcd.com/979/

Re: Error when cloning with weird local directory

[Torsten Bögershausen]

On 2015-08-06 06.21, Chris Packham wrote:
> Hi All,
> 
> A developer at $dayjob called me over to have a look at a git error he
> was getting (names changed to protect the innocent).
> 
>   $ git --version
>   git version 2.5.0
>   $ git clone ssh://example.com/repo.git
>   Cloning into 'repo'...
>   fatal: I don't handle protocol '/home/user/src/ssh'
> 
> After a bit of head scratching we found that he had a local directory
> structure called 'ssh://example.com/repo.git' it wasn't a complete
> repo but it had some of the things one expects to find in a .git
> directory (info, objects, refs, etc). It had been there for a while
> and we suspect was created by a scp gone wrong from the last time he
> was dealing with repo.git.
> 
> I'm wondering if it's worth catching this kind of weirdness and
> erroring out with a slightly more useful message. I'm also wondering
> what would have happened if this repo was actually a full and complete
> thing.
> 
> I'm not sure that there is a problem worth solving here. I can provide
> an anonymized tarball of the directory structure in question if anyone
> is interested. But maybe this is useful for future mailing list
> searchers[1].
> 
> Thanks,
> Chris
This is indeed a bug:

It looks as if
static char *get_repo_path(const char *repo, int *is_bundle)
in built/clone.c
checks if there is a local directory structure looking like a
.git directory.
This is wrong.
There should be a check for the scheme first.


It is not the error message that is confusing, we should never get there,
but invoke ssh instead.

The bug is in clone.c

Re: Error when cloning with weird local directory

[Junio C Hamano]

Torsten Bögershausen <tboegi@web.de> writes:

> It looks as if
> static char *get_repo_path(const char *repo, int *is_bundle)
> in built/clone.c
> checks if there is a local directory structure looking like a
> .git directory.
> This is wrong.

It is as designed, though, to allow cloning from a local directory
with any name.

> There should be a check for the scheme first.

That will be wrong.

Re: Error when cloning with weird local directory

[Junio C Hamano]

Junio C Hamano <gitster@pobox.com> writes:

> Torsten Bögershausen <tboegi@web.de> writes:
>
>> It looks as if
>> static char *get_repo_path(const char *repo, int *is_bundle)
>> in built/clone.c
>> checks if there is a local directory structure looking like a
>> .git directory.
>> This is wrong.
>
> It is as designed, though, to allow cloning from a local directory
> with any name.
>
>> There should be a check for the scheme first.
>
> That will be wrong.

It matters mostly when dealing with scp-like syntax, word:path.

I _think_ taking notice of "word://" (with doubled slashes) and
treating it specially will not introduce any new issue; while it is
still OK for users to have a local directory called "word:", if they
meant a subdirectory of it, they wouldn't have typed double-slashes
there.

Re: Error when cloning with weird local directory

[Torsten Bögershausen]

On 2015-08-06 09.50, Junio C Hamano wrote:
> Junio C Hamano <gitster@pobox.com> writes:
> 
>> Torsten Bögershausen <tboegi@web.de> writes:
>>
>>> It looks as if
>>> static char *get_repo_path(const char *repo, int *is_bundle)
>>> in built/clone.c
>>> checks if there is a local directory structure looking like a
>>> .git directory.
>>> This is wrong.
>>
>> It is as designed, though, to allow cloning from a local directory
>> with any name.
I see the point, but this is what I would expect as a user:

git clone ssh://host/path         # Always ssh, never local
git clone ./ssh://host/path       # Always local
git clone host:path               # scp syntax, border case:
                                  # if a git repo host:path exists on disc,
                                  # use it
git clone ./host:path             # local, not scp ('/' before ':')

Beside that, git fetch, git fetch-pack all use the transport helper from
transport.c:
transport
struct transport *transport_get(struct remote *remote, const char *url)

to let the URL being parsed and to make the decision if an URL without a scheme
is ssh or a local file.

So I think that git clone can be slighty more consistant here.




>>
>>> There should be a check for the scheme first.
>>
>> That will be wrong.
> 
> It matters mostly when dealing with scp-like syntax, word:path.
> 
> I _think_ taking notice of "word://" (with doubled slashes) and
> treating it specially will not introduce any new issue; while it is
> still OK for users to have a local directory called "word:", if they
> meant a subdirectory of it, they wouldn't have typed double-slashes
> there.
> --
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> 

Re: Error when cloning with weird local directory

[Junio C Hamano]

Torsten Bögershausen <tboegi@web.de> writes:

> So I think that git clone can be slighty more consistant here.

Sure.

>> I _think_ taking notice of "word://" (with doubled slashes) and
>> treating it specially will not introduce any new issue; while it is
>> still OK for users to have a local directory called "word:", if they
>> meant a subdirectory of it, they wouldn't have typed double-slashes
>> there.