Re: [PATCH 2/2] mingw: allow absolute paths without drive prefix
- From
Johannes Sixt <j6t@kdbg.org>
- Date
- Dec 11, 2018, 20:36 UTC
- Message-ID
- <8a484f86-1d43-fc0a-22b4-39c770cda6cb@kdbg.org>
- In-Reply-To
- <nycvar.QRO.7.76.6.1812111134250.43@tvgsbejvaqbjf.bet>
Am 11.12.18 um 12:25 schrieb Johannes Schindelin:
Show 26 quoted lines
> On Mon, 10 Dec 2018, Johannes Sixt wrote:
>>> diff --git a/compat/mingw.c b/compat/mingw.c
>>> index 34b3880b29..4d009901d8 100644
>>> --- a/compat/mingw.c
>>> +++ b/compat/mingw.c
>>> @@ -928,11 +928,19 @@ unsigned int sleep (unsigned int seconds)
>>> char *mingw_mktemp(char *template)
>>> {
>>> wchar_t wtemplate[MAX_PATH];
>>> + int offset = 0;
>>> +
>>> if (xutftowcs_path(wtemplate, template) < 0)
>>> return NULL;
>>> +
>>> + if (is_dir_sep(template[0]) && !is_dir_sep(template[1]) &&
>>> + iswalpha(wtemplate[0]) && wtemplate[1] == L':') {
>>> + /* We have an absolute path missing the drive prefix */
>>
>> This comment is true for the source part, template, but I can't find
>> where the destination, wtemplate, suddenly gets the drive prefix. As far
>> as I can see, xutftowcs_path() just does a plain textual conversion
>> without any interpretation of the text as path. Can you explain it?
>
> It is legal on Windows for such a path to lack the drive prefix, also in
> the wide-character version. So the explanation is: even `wtemplate` won't
> get the drive prefix. It does not need to.I'm sorry, my question was extremely fuzzy. I actually wanted to know how the condition that you introduce in this patch can ever be true.
And after looking at the Git for Windows code, I could answer it myself: it cannot. Not with this patch alone. In GfW, there is additional code in xutftowcs_path() that massages wtemplate to receive a drive prefix; but vanilla Git does not have that code, so that is_dir_sep(template[0]) and iswalpha(wtemplate[0]) can never be true at the same time at this point.
-- Hannes