v3, 2 partsallow git-svn fetching to work using serf

> +sub temp_is_locked {
> +	my ($self, $name) = _maybe_self( <at> _);
> +	my $temp_fd = \$TEMP_FILEMAP{$name};
> +
> +	defined $$temp_fd && $$temp_fd->opened && $TEMP_FILES{$$temp_fd}{locked};
> +}
> +
>  =item temp_release ( NAME )
> 
>  =item temp_release ( FILEHANDLE )
>  <at>  <at>  -1248,7 +1277,7  <at>  <at>  sub _temp_cache {
> 
>  	my $temp_fd = \$TEMP_FILEMAP{$name};
>  	if (defined $$temp_fd and $$temp_fd->opened) {
> -		if ($TEMP_FILES{$$temp_fd}{locked}) {
> +		if (temp_is_locked($name)) {
>  			throw Error::Simple("Temp file with moniker '" .
>  				$name . "' already in use");
>  		}

> Kyle J. McKay <mackyle <at> gmail.com> writes:
>
>> +sub temp_is_locked {
>> +	my ($self, $name) = _maybe_self( <at> _);
>> +	my $temp_fd = \$TEMP_FILEMAP{$name};
>> +
>> +	defined $$temp_fd && $$temp_fd->opened && $TEMP_FILES{$$temp_fd} 
>> {locked};
>> +}
>> +
>> =item temp_release ( NAME )
>>
>> =item temp_release ( FILEHANDLE )
>> <at>  <at>  -1248,7 +1277,7  <at>  <at>  sub _temp_cache {
>>
>> 	my $temp_fd = \$TEMP_FILEMAP{$name};
>> 	if (defined $$temp_fd and $$temp_fd->opened) {
>> -		if ($TEMP_FILES{$$temp_fd}{locked}) {
>> +		if (temp_is_locked($name)) {
>> 			throw Error::Simple("Temp file with moniker '" .
>> 				$name . "' already in use");
>> 		}
>
> There's a problem with this use of temp_is_locked. There is an else
> clause right after this:
>
> 	} else {
> 		if (defined $$temp_fd) {
> 			# then we're here because of a closed handle.
>
> Prior to the patch, the comment is correct, but after the patch, the
> if block may also be entered if the file is open but locked. This is
> because temp_is_locked checks that the temp file is defined, open,
> and locked.
>
> This issue leads to lots of
>
>  Temp file 'svn_delta_3360_0' was closed. Opening replacement.
>
> messages for me.
>
> Reverting the change in _temp_cache solves the problem for me.
> Adding an " && !$$temp_fd->opened" clause to the if statement also
> works, but this is less efficient.

> Hi,
>
> Kyle McKay wrote:
>
>> The temp_is_locked function can be used to determine whether
>> or not a given name previously passed to temp_acquire is
>> currently locked.
> [...]
>> +=item temp_is_locked ( NAME )
>> +
>> +Returns true if the file mapped to C<NAME> is currently locked.
>> +
>> +If true is returned, an attempt to C<temp_acquire()> the same
>

> That change was made as a result of this feedback:
>
> On Jul 6, 2013, at 17:11, Jonathan Nieder wrote:
>> Kyle McKay wrote:
>>
>>> The temp_is_locked function can be used to determine whether
>>> or not a given name previously passed to temp_acquire is
>>> currently locked.
>> [...]
>>> +=item temp_is_locked ( NAME )
>>> +
>>> +Returns true if the file mapped to C<NAME> is currently locked.
>>> +
>>> +If true is returned, an attempt to C<temp_acquire()> the same
>>
> [snip]
>
>> Looking more closely, it looks like this is factoring out the idiom
>> for checking if a name is already in use from the _temp_cache
>> function.  Would it make sense for _temp_cache to call this helper?
>
> So I think the answer is it does not make sense for _temp_cache to
> call this helper.

> From: "Kyle J. McKay" <mackyle@gmail.com>
>
> This patch allows git-svn to fetch successfully using the
> serf library when given an https?: url to fetch from.
>
> Unfortunately some svn servers do not seem to be configured
> well for use with the serf library.  This can cause fetching
> to take longer compared to the neon library or actually
> cause timeouts during the fetch.  When timeouts occur
> git-svn can be safely restarted to fetch more revisions.
>
> A new temp_is_locked function has been added to Git.pm
> to facilitate using the minimal number of temp files
> possible when using serf.
>
> The problem that occurs when running git-svn fetch using
> the serf library is that the previously used temp file
> is not always unlocked before the next temp file needs
> to be used.
>
> To work around this problem, a new temp name is used
> if the temp name that would otherwise be chosen is
> currently locked.
>
> Version v2 of the patch introduced a bug when changing the _temp_cache
> function to use the new temp_is_locked function at the suggestion of a
> reviewer.  That has now been resolved.