Re: fatal: Could not get current working directory: Permission denied | affected 2.10,2.11,2.12, but not 1.9.5 |
- From
René Scharfe <l.s.r@web.de>
- Date
- Mar 17, 2017, 21:07 UTC
- Message-ID
- <250f6b35-03c3-1fa8-8b6b-dfdc42660d8c@web.de>
- In-Reply-To
- <CAGZ79kbpPBN21mbN2F20ikr6dXrKEcY=msqymaG8TOujeQF0jw@mail.gmail.com>
Am 17.03.2017 um 20:45 schrieb Stefan Beller:
Show 51 quoted lines
> On Fri, Mar 17, 2017 at 12:34 PM, René Scharfe <l.s.r@web.de> wrote:
>> Am 15.03.2017 um 22:30 schrieb René Scharfe:
>>> Am 15.03.2017 um 10:44 schrieb Zenobiusz Kunegunda:
>>>> $ git bisect bad
>>>> 7333ed1788b4f2b162a35003044d77a716732a1f is the first bad commit
>>>> commit 7333ed1788b4f2b162a35003044d77a716732a1f
>>>> Author: René Scharfe <l.s.r@web.de>
>>>> Date: Mon Jul 28 20:26:40 2014 +0200
>>>>
>>>> setup: convert setup_git_directory_gently_1 et al. to strbuf
>>>
>>> That's what I half-suspected, and I think by now I got an idea. Here's
>>> a test program:
>>
>> And here's a patch for letting strbuf_getcwd() use the same getcwd(3)
>> extension that pwd(1) uses. It avoids the need to guess the path's
>> length and thus reduces the chance of stumbling over strange error
>> codes. I wonder if it helps in your case.
>>
>> René
>>
>> ---
>> strbuf.c | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>>
>> diff --git a/strbuf.c b/strbuf.c
>> index ace58e7367..4c02801edd 100644
>> --- a/strbuf.c
>> +++ b/strbuf.c
>> @@ -442,6 +442,14 @@ int strbuf_getcwd(struct strbuf *sb)
>> {
>> size_t oldalloc = sb->alloc;
>> size_t guessed_len = 128;
>> + char *cwd;
>> +
>> + cwd = getcwd(NULL, 0);
>
> from my local man pages:
>
> As an extension to the POSIX.1-2001 standard, Linux (libc4, libc5,
> glibc) getcwd()
> allocates the buffer dynamically using malloc(3) if buf is NULL. In
> this case, the
> allocated buffer has the length size unless size is zero, when buf
> is allocated as big
> as necessary. The caller should free(3) the returned buffer.
>
> This sounds specific to Linux (though I am reading Linux man pages,
> which claim this; Also it seems I might have misread it as it also states
> "The pathname is returned as the function result and via the
> argument buf, if present.").I'm only interested in FreeBSD for now, as that's the platform Zenobiusz reported the issue on and I haven't been able to reproduce it, so this is still a bit exploratory, but hopefully getting closer. This extension is used in the first version of pwd(1) in FreeBSD's repo, comitted 1994-05-26, so it was supported there basically forever.
The oldest version I found that's using the extention is NetBSD's pwd(1), which was committed 1993-03-21 and carries a SCCS timestamp of 1991-02-20. Visual Studio .NET 2003 supports it as well.
Show 10 quoted lines
> Looking further:
>
> These functions are often used to save the location of the current
> working directory for the purpose of returning to it later. Opening the
> current directory (".") and calling fchdir(2) to return is
> usually a faster
> and more reliable alternative when sufficiently many file descriptors are
> available, especially on platforms other than Linux.
>
> Not sure if that opens another door here?Reducing the use of absolute paths may be a good idea in general, but that would probably require major changes. And Windows doesn't seem to offer fchdir() at all; I don't know if it has an equivalent function that could be used to build a replacement.
René