The original patch that lead to an earlier commit adbc0b6 (cygwin: Use
native Win32 API for stat, 2008-09-30) did not call git_default_config()
and it was a good thing. The lazy config reading when lstat/stat is
called for the first time to find out if core.filemode is set can happen
anytime in the calling program. If it happens after the calling program
parsed the configuration file to prime its default parameter settings and
processed its command line parameters to tweak them, this will overwrite
the values set by the program with the values read from the config file.
This essentially reverts the code to the version as submitted by Mark,
with a bit more comments to clarify why we do not fall back on the default
configuration parser from git_cygwin_config().
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Cygwin's POSIX emulation allows use of core.filemode true, unlike native
Window's implementation of stat / lstat, and Cygwin/git users who have
configured core.filemode true in various repositories will be very
unpleasantly surprised to find that git is no longer honoring that option.
So, this patch forces use of Cygwin's stat functions if core.filemode is
set true, regardless of any other considerations.
Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
lstat/stat functions in Cygwin are very slow, because they try to emulate
some *nix things that Git does not actually need. This patch adds Win32
specific implementation of these functions for Cygwin.
This implementation handles most situation directly but in some rare cases
it falls back on the implementation provided for Cygwin. This is necessary
for two reasons:
- Cygwin has its own file hierarchy, so absolute paths used in Cygwin is
not suitable to be used Win32 API. cygwin_conv_to_win32_path can not be
used because it automatically dereference Cygwin symbol links, also it
causes extra syscall. Fortunately Git rarely use absolute paths, so we
always use Cygwin implementation for absolute paths.
- Support of symbol links. Cygwin stores symbol links as ordinary using
one of two possible formats. Therefore, the fast implementation falls
back to Cygwin functions if it detects potential use of symbol links.
The speed of this implementation should be the same as mingw_lstat for
common cases, but it is considerable slower when the specified file name
does not exist.
Despite all efforts to make the fast implementation as robust as possible,
it may not work well for some very rare situations. I am aware only one
situation: use Cygwin mount to bind unrelated paths inside repository
together. Therefore, the core.ignoreCygwinFSTricks configuration option is
provided, which controls whether native or Cygwin version of stat is used.
Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Junio C Hamano
Mark Levedahl
Dmitry Potapov