On Cygwin, similar to Windows, "git push //server/share/repository"
ought to mean a repository on a network share that can be accessed
locally, but this did not work correctly due to stripping the double
slashes at the beginning.

This may need to be heavily tested before it gets unleashed to the
wild, as the change is at a fairly low-level code and would affect
not just the code to decide if the push destination is local.  There
may be unexpected fallouts in the path normalization.

* tb/push-to-cygwin-unc-path:
  cygwin: allow pushing to UNC paths

 cygwin can use an UNC path like //server/share/repo

 $ cd //server/share/dir
 $ mkdir test
 $ cd test
 $ git init --bare

 However, when we try to push from a local Git repository to this repo,
 there is a problem: Git converts the leading "//" into a single "/".

 As cygwin handles an UNC path so well, Git can support them better:

 - Introduce cygwin_offset_1st_component() which keeps the leading "//",
   similar to what Git for Windows does.

 - Move CYGWIN out of the POSIX in the tests for path normalization in t0060

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.

* bw/config-h:
  config: don't implicitly use gitdir or commondir
  config: respect commondir
  setup: teach discover_git_directory to respect the commondir
  config: don't include config.h by default
  config: remove git_config_iter
  config: create config.h

Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

We often try to open a file for reading whose existence is
optional, and silently ignore errors from open/fopen; report such
errors if they are not due to missing files.

* nd/fopen-errors:
  mingw_fopen: report ENOENT for invalid file names
  mingw: verify that paths are not mistaken for remote nicknames
  log: fix memory leak in open_next_file()
  rerere.c: move error_errno() closer to the source system call
  print errno when reporting a system call error
  wrapper.c: make warn_on_inaccessible() static
  wrapper.c: add and use fopen_or_warn()
  wrapper.c: add and use warn_on_fopen_errors()
  config.mak.uname: set FREAD_READS_DIRECTORIES for Darwin, too
  config.mak.uname: set FREAD_READS_DIRECTORIES for Linux and FreeBSD
  clone: use xfopen() instead of fopen()
  use xfopen() in more places
  git_fopen: fix a sparse 'not declared' warning

"foo\bar\baz" in "git fetch foo\bar\baz", even though there is no
slashes in it, cannot be a nickname for a remote on Windows, as
that is likely to be a pathname on a local filesystem.

* js/bs-is-a-dir-sep-on-windows:
  Windows: do not treat a path with backslashes as a remote's nick name
  mingw.h: permit arguments with side effects for is_dir_sep

Code simplification.

* rs/mingw-path-lookup-simplify:
  mingw: simplify PATH handling

"foo\bar\baz" in "git fetch foo\bar\baz", even though there is no
slashes in it, cannot be a nickname for a remote on Windows, as
that is likely to be a pathname on a local filesystem.

* js/bs-is-a-dir-sep-on-windows:
  Windows: do not treat a path with backslashes as a remote's nick name
  mingw.h: permit arguments with side effects for is_dir_sep

On Windows, certain characters are prohibited in file names, most
prominently the colon. When fopen() is called with such an invalid file
name, the underlying Windows API actually reports a particular error,
but since there is no suitable errno value, this error is translated
to EINVAL. Detect the case and report ENOENT instead.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>