* [PATCH] fix pushing to //server/share/dir paths on Windows
@ 2016-12-13 21:32 Johannes Sixt
2016-12-13 22:48 ` Junio C Hamano
` (2 more replies)
0 siblings, 3 replies; 8+ messages in thread
From: Johannes Sixt @ 2016-12-13 21:32 UTC (permalink / raw)
To: Johannes Schindelin; +Cc: Jeff King, Git Mailing List
normalize_path_copy() is not prepared to keep the double-slash of a
//server/share/dir kind of path, but treats it like a regular POSIX
style path and transforms it to /server/share/dir.
The bug manifests when 'git push //server/share/dir master' is run,
because tmp_objdir_add_as_alternate() uses the path in normalized
form when it registers the quarantine object database via
link_alt_odb_entries(). Needless to say that the directory cannot be
accessed using the wrongly normalized path.
Fix it by skipping all of the root part, not just a potential drive
prefix. offset_1st_component takes care of this, see the
implementation in compat/mingw.c::mingw_offset_1st_component().
There is a change in behavior: \\server\share is not transformed
into //server/share anymore, but all subsequent directory separators
are rewritten to '/'. This should not make a difference; Windows can
handle the mix. In the context of 'git push' this cannot be verified,
though, as there seems to be an independent bug that transforms the
double '\\' to a single '\' on the way.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
Another long-standing bug uncovered by the quarantine series.
Dscho, it looks like this could fix the original report at
https://github.com/git-for-windows/git/issues/979
This patch should cook well because of the change in behavior.
I would not be surprised if there is some fall-out.
The other bug I'm alluding to, I still have to investigate. I do
not think that it can be counted as fall-out.
path.c | 24 +++++++++++++++---------
1 file changed, 15 insertions(+), 9 deletions(-)
diff --git a/path.c b/path.c
index 52d889c88e..02dc70fb92 100644
--- a/path.c
+++ b/path.c
@@ -991,7 +991,7 @@ const char *remove_leading_path(const char *in, const char *prefix)
*
* Performs the following normalizations on src, storing the result in dst:
* - Ensures that components are separated by '/' (Windows only)
- * - Squashes sequences of '/'.
+ * - Squashes sequences of '/' except "//server/share" on Windows
* - Removes "." components.
* - Removes ".." components, and the components the precede them.
* Returns failure (non-zero) if a ".." component appears as first path
@@ -1014,17 +1014,23 @@ const char *remove_leading_path(const char *in, const char *prefix)
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
{
char *dst0;
- int i;
-
- for (i = has_dos_drive_prefix(src); i > 0; i--)
- *dst++ = *src++;
- dst0 = dst;
+ int offset;
- if (is_dir_sep(*src)) {
+ /*
+ * Handle initial part of absolute path: "/", "C:/", "\\server\share/".
+ */
+ offset = offset_1st_component(src);
+ if (offset) {
+ /* Convert the trailing separator to '/' on Windows. */
+ memcpy(dst, src, offset - 1);
+ dst += offset - 1;
*dst++ = '/';
- while (is_dir_sep(*src))
- src++;
+ src += offset;
}
+ dst0 = dst;
+
+ while (is_dir_sep(*src))
+ src++;
for (;;) {
char c = *src;
--
2.11.0.79.g263f27a
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] fix pushing to //server/share/dir paths on Windows
2016-12-13 21:32 [PATCH] fix pushing to //server/share/dir paths on Windows Johannes Sixt
@ 2016-12-13 22:48 ` Junio C Hamano
2016-12-14 17:30 ` Jeff King
2016-12-19 17:18 ` [PATCH] fix pushing to //server/share/dir paths " Johannes Schindelin
2 siblings, 0 replies; 8+ messages in thread
From: Junio C Hamano @ 2016-12-13 22:48 UTC (permalink / raw)
To: Johannes Sixt; +Cc: Johannes Schindelin, Jeff King, Git Mailing List
Johannes Sixt <j6t@kdbg.org> writes:
> There is a change in behavior: \\server\share is not transformed
> into //server/share anymore, but all subsequent directory separators
> are rewritten to '/'. This should not make a difference; Windows can
> handle the mix.
I saw Dscho had a similar "windows can handle the mix" change in an
earlier development cycle, I think, and this is being consistent.
> Another long-standing bug uncovered by the quarantine series.
>
> Dscho, it looks like this could fix the original report at
> https://github.com/git-for-windows/git/issues/979
>
> This patch should cook well because of the change in behavior.
> I would not be surprised if there is some fall-out.
>
> The other bug I'm alluding to, I still have to investigate. I do
> not think that it can be counted as fall-out.
>
> path.c | 24 +++++++++++++++---------
> 1 file changed, 15 insertions(+), 9 deletions(-)
Thanks.
> diff --git a/path.c b/path.c
> index 52d889c88e..02dc70fb92 100644
> --- a/path.c
> +++ b/path.c
> @@ -991,7 +991,7 @@ const char *remove_leading_path(const char *in, const char *prefix)
> *
> * Performs the following normalizations on src, storing the result in dst:
> * - Ensures that components are separated by '/' (Windows only)
> - * - Squashes sequences of '/'.
> + * - Squashes sequences of '/' except "//server/share" on Windows
"on windows" because offset_1st_component() does the magic only
there? Makes sense.
> * - Removes "." components.
> * - Removes ".." components, and the components the precede them.
> * Returns failure (non-zero) if a ".." component appears as first path
> @@ -1014,17 +1014,23 @@ const char *remove_leading_path(const char *in, const char *prefix)
> int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
> {
> char *dst0;
> - int i;
> -
> - for (i = has_dos_drive_prefix(src); i > 0; i--)
> - *dst++ = *src++;
> - dst0 = dst;
> + int offset;
>
> - if (is_dir_sep(*src)) {
> + /*
> + * Handle initial part of absolute path: "/", "C:/", "\\server\share/".
> + */
> + offset = offset_1st_component(src);
> + if (offset) {
> + /* Convert the trailing separator to '/' on Windows. */
> + memcpy(dst, src, offset - 1);
> + dst += offset - 1;
> *dst++ = '/';
> - while (is_dir_sep(*src))
> - src++;
> + src += offset;
> }
> + dst0 = dst;
By resetting dst0 here, we ensure that up_one that is triggered by
seeing "../" will not escape the \\server\share\ part, which makes
sense to me.
> + while (is_dir_sep(*src))
> + src++;
>
> for (;;) {
> char c = *src;
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] fix pushing to //server/share/dir paths on Windows
2016-12-13 21:32 [PATCH] fix pushing to //server/share/dir paths on Windows Johannes Sixt
2016-12-13 22:48 ` Junio C Hamano
@ 2016-12-14 17:30 ` Jeff King
2016-12-14 19:37 ` [PATCH v2] fix pushing to //server/share/dir " Johannes Sixt
2016-12-19 17:18 ` [PATCH] fix pushing to //server/share/dir paths " Johannes Schindelin
2 siblings, 1 reply; 8+ messages in thread
From: Jeff King @ 2016-12-14 17:30 UTC (permalink / raw)
To: Johannes Sixt; +Cc: Johannes Schindelin, Git Mailing List
On Tue, Dec 13, 2016 at 10:32:01PM +0100, Johannes Sixt wrote:
> normalize_path_copy() is not prepared to keep the double-slash of a
> //server/share/dir kind of path, but treats it like a regular POSIX
> style path and transforms it to /server/share/dir.
>
> The bug manifests when 'git push //server/share/dir master' is run,
> because tmp_objdir_add_as_alternate() uses the path in normalized
> form when it registers the quarantine object database via
> link_alt_odb_entries(). Needless to say that the directory cannot be
> accessed using the wrongly normalized path.
Thanks for digging this up! I had a feeling that the problem was going
to be in the underlying path code, but I didn't want to just pass the
buck without evidence. :)
> - if (is_dir_sep(*src)) {
> + /*
> + * Handle initial part of absolute path: "/", "C:/", "\\server\share/".
> + */
> + offset = offset_1st_component(src);
> + if (offset) {
> + /* Convert the trailing separator to '/' on Windows. */
> + memcpy(dst, src, offset - 1);
> + dst += offset - 1;
> *dst++ = '/';
Hmm. So this is the "change-of-behavior" bit. Would it be reasonable to
write:
/* Copy initial part of absolute path, converting separators on Windows */
const char *end = src + offset_1st_component(src);
while (src < end) {
char c = *src++;
if (c == '\\')
c = '/';
*dst++ = c;
}
? I'm not sure if it's wrong to convert backslashes in that first
component or not (but certainly we were before). I don't think we'd need
is_dir_sep() in that "if()", because we can leave slashes as-is. But
maybe it would make the code easier to read.
-Peff
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH v2] fix pushing to //server/share/dir on Windows
2016-12-14 17:30 ` Jeff King
@ 2016-12-14 19:37 ` Johannes Sixt
2016-12-15 7:30 ` Torsten Bögershausen
0 siblings, 1 reply; 8+ messages in thread
From: Johannes Sixt @ 2016-12-14 19:37 UTC (permalink / raw)
To: Jeff King; +Cc: Johannes Schindelin, Git Mailing List
normalize_path_copy() is not prepared to keep the double-slash of a
//server/share/dir kind of path, but treats it like a regular POSIX
style path and transforms it to /server/share/dir.
The bug manifests when 'git push //server/share/dir master' is run,
because tmp_objdir_add_as_alternate() uses the path in normalized
form when it registers the quarantine object database via
link_alt_odb_entries(). Needless to say that the directory cannot be
accessed using the wrongly normalized path.
Fix it by skipping all of the root part, not just a potential drive
prefix. offset_1st_component takes care of this, see the
implementation in compat/mingw.c::mingw_offset_1st_component().
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
---
Am 14.12.2016 um 18:30 schrieb Jeff King:
> Would it be reasonable to
> write:
>
> /* Copy initial part of absolute path, converting separators on Windows */
> const char *end = src + offset_1st_component(src);
> while (src < end) {
> char c = *src++;
> if (c == '\\')
> c = '/';
> *dst++ = c;
> }
Makes a lot of sense! I haven't had an opportunity, though, to test
on Windows.
> ? I'm not sure if it's wrong to convert backslashes in that first
> component or not (but certainly we were before). I don't think we'd need
> is_dir_sep() in that "if()", because we can leave slashes as-is. But
> maybe it would make the code easier to read.
is_dir_sep() is preferable, IMO.
I also changed the commit message and subject line slightly.
path.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/path.c b/path.c
index 52d889c88e..efcedafba6 100644
--- a/path.c
+++ b/path.c
@@ -991,7 +991,7 @@ const char *remove_leading_path(const char *in, const char *prefix)
*
* Performs the following normalizations on src, storing the result in dst:
* - Ensures that components are separated by '/' (Windows only)
- * - Squashes sequences of '/'.
+ * - Squashes sequences of '/' except "//server/share" on Windows
* - Removes "." components.
* - Removes ".." components, and the components the precede them.
* Returns failure (non-zero) if a ".." component appears as first path
@@ -1014,17 +1014,22 @@ const char *remove_leading_path(const char *in, const char *prefix)
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len)
{
char *dst0;
- int i;
+ const char *end;
- for (i = has_dos_drive_prefix(src); i > 0; i--)
- *dst++ = *src++;
+ /*
+ * Copy initial part of absolute path: "/", "C:/", "//server/share/".
+ */
+ end = src + offset_1st_component(src);
+ while (src < end) {
+ char c = *src++;
+ if (is_dir_sep(c))
+ c = '/';
+ *dst++ = c;
+ }
dst0 = dst;
- if (is_dir_sep(*src)) {
- *dst++ = '/';
- while (is_dir_sep(*src))
- src++;
- }
+ while (is_dir_sep(*src))
+ src++;
for (;;) {
char c = *src;
--
2.11.0.79.g263f27a
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH v2] fix pushing to //server/share/dir on Windows
2016-12-14 19:37 ` [PATCH v2] fix pushing to //server/share/dir " Johannes Sixt
@ 2016-12-15 7:30 ` Torsten Bögershausen
2016-12-15 11:01 ` Jeff King
0 siblings, 1 reply; 8+ messages in thread
From: Torsten Bögershausen @ 2016-12-15 7:30 UTC (permalink / raw)
To: Johannes Sixt, Jeff King; +Cc: Johannes Schindelin, Git Mailing List
On 14/12/16 20:37, Johannes Sixt wrote:
> normalize_path_copy() is not prepared to keep the double-slash of a
> //server/share/dir kind of path, but treats it like a regular POSIX
> style path and transforms it to /server/share/dir.
>
> The bug manifests when 'git push //server/share/dir master' is run,
> because tmp_objdir_add_as_alternate() uses the path in normalized
> form when it registers the quarantine object database via
> link_alt_odb_entries(). Needless to say that the directory cannot be
> accessed using the wrongly normalized path.
>
> Fix it by skipping all of the root part, not just a potential drive
> prefix. offset_1st_component takes care of this, see the
> implementation in compat/mingw.c::mingw_offset_1st_component().
>
> Signed-off-by: Johannes Sixt <j6t@kdbg.org>
> ---
> Am 14.12.2016 um 18:30 schrieb Jeff King:
>> Would it be reasonable to
>> write:
>>
>> /* Copy initial part of absolute path, converting separators on Windows */
>> const char *end = src + offset_1st_component(src);
>> while (src < end) {
>> char c = *src++;
>> if (c == '\\')
>> c = '/';
>> *dst++ = c;
>> }
> Makes a lot of sense! I haven't had an opportunity, though, to test
> on Windows.
I'm not sure, if a conversion should be done here, in this part of code.
To my knowledge,
C:\dir1\file
is the same
as
C:/dir1/file
and that is handled by windows.
The \\server\share\dir1\file is native to windows,
and I can't see good reasons to change '\' into '/' somewhere in Git,
when UNC is used.
Cygwin does a translation from
//server/share/dir1/file
into
\\server\share\dir1\file
In other words:
The patch looks good as is, and once I get a Windows machine,
may be able to do some testing and come up with test cases
<https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx>
[]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] fix pushing to //server/share/dir on Windows
2016-12-15 7:30 ` Torsten Bögershausen
@ 2016-12-15 11:01 ` Jeff King
2016-12-15 17:49 ` Junio C Hamano
0 siblings, 1 reply; 8+ messages in thread
From: Jeff King @ 2016-12-15 11:01 UTC (permalink / raw)
To: Torsten Bögershausen
Cc: Johannes Sixt, Johannes Schindelin, Git Mailing List
On Thu, Dec 15, 2016 at 08:30:52AM +0100, Torsten Bögershausen wrote:
> > > Would it be reasonable to
> > > write:
> > >
> > > /* Copy initial part of absolute path, converting separators on Windows */
> > > const char *end = src + offset_1st_component(src);
> > > while (src < end) {
> > > char c = *src++;
> > > if (c == '\\')
> > > c = '/';
> > > *dst++ = c;
> > > }
> > Makes a lot of sense! I haven't had an opportunity, though, to test
> > on Windows.
> I'm not sure, if a conversion should be done here, in this part of code.
> To my knowledge,
>
> C:\dir1\file
> is the same
> as
> C:/dir1/file
> and that is handled by windows.
I don't have an opinion either way on what Windows would want, but note
that the function already _does_ convert separators to slashes. With
Johannes's original patch, you'd end up with a mix, like:
\\server\share/dir1/file
So this conversion is really just retaining the original behavior, and
making it consistent throughout the path.
Which isn't to say that the function as it currently exists isn't a
little bit buggy. :)
One of the points of normalizing, though, is that Git can then do
textual comparisons between the output. So I think there's value in
having a canonical internal representation, even if the OS could handle
more exotic ones.
-Peff
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH v2] fix pushing to //server/share/dir on Windows
2016-12-15 11:01 ` Jeff King
@ 2016-12-15 17:49 ` Junio C Hamano
0 siblings, 0 replies; 8+ messages in thread
From: Junio C Hamano @ 2016-12-15 17:49 UTC (permalink / raw)
To: Jeff King
Cc: Torsten Bögershausen, Johannes Sixt, Johannes Schindelin,
Git Mailing List
Jeff King <peff@peff.net> writes:
> I don't have an opinion either way on what Windows would want, but note
> that the function already _does_ convert separators to slashes. With
> Johannes's original patch, you'd end up with a mix, like:
>
> \\server\share/dir1/file
>
> So this conversion is really just retaining the original behavior, and
> making it consistent throughout the path.
>
> Which isn't to say that the function as it currently exists isn't a
> little bit buggy. :)
>
> One of the points of normalizing, though, is that Git can then do
> textual comparisons between the output. So I think there's value in
> having a canonical internal representation, even if the OS could handle
> more exotic ones.
E.g. the log message of d53c2c6738 ("mingw: fix t9700's assumption
about directory separators", 2016-01-27) says the two kinds of
slashes are equivalent over there, but the patch text ends up doing
exactly that normalization.
5ca6b7bb47 ("config --show-origin: report paths with forward
slashes", 2016-03-23) is an example of us trying to normalize in
order to give consistent output to the users.
Having said all that, I do not have an opinion either way on what
Windows would want, either ;-)
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] fix pushing to //server/share/dir paths on Windows
2016-12-13 21:32 [PATCH] fix pushing to //server/share/dir paths on Windows Johannes Sixt
2016-12-13 22:48 ` Junio C Hamano
2016-12-14 17:30 ` Jeff King
@ 2016-12-19 17:18 ` Johannes Schindelin
2 siblings, 0 replies; 8+ messages in thread
From: Johannes Schindelin @ 2016-12-19 17:18 UTC (permalink / raw)
To: Johannes Sixt; +Cc: Jeff King, Git Mailing List
Hi Hannes,
On Tue, 13 Dec 2016, Johannes Sixt wrote:
> Dscho, it looks like this could fix the original report at
> https://github.com/git-for-windows/git/issues/979
Yes, thank you so much for fixing it!
I think your v2 is safe enough to cherry-pick directly into Git for
Windows' `master`.
Thanks,
Dscho
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2016-12-19 17:19 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2016-12-13 21:32 [PATCH] fix pushing to //server/share/dir paths on Windows Johannes Sixt
2016-12-13 22:48 ` Junio C Hamano
2016-12-14 17:30 ` Jeff King
2016-12-14 19:37 ` [PATCH v2] fix pushing to //server/share/dir " Johannes Sixt
2016-12-15 7:30 ` Torsten Bögershausen
2016-12-15 11:01 ` Jeff King
2016-12-15 17:49 ` Junio C Hamano
2016-12-19 17:18 ` [PATCH] fix pushing to //server/share/dir paths " Johannes Schindelin
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