libgit2 · csware · Jan 14, 2017 · Jan 14, 2017 · Jan 14, 2017 · Jan 14, 2017
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -56,6 +56,10 @@ v0.25
 
 ### API additions
 
+* You can now set the default share modes on Windows for opening files using
+  `GIT_OPT_SET_WINDOWS_SHAREMODE` option with `git_libgit2_opts()`.
+  It is the counterpart to `GIT_OPT_GET_WINDOWS_SHAREMODE`.
+
 * You can now get the user-agent used by libgit2 using the
   `GIT_OPT_GET_USER_AGENT` option with `git_libgit2_opts()`.
   It is the counterpart to `GIT_OPT_SET_USER_AGENT`.

diff --git a/include/git2/common.h b/include/git2/common.h
@@ -180,6 +180,8 @@ typedef enum {
 	GIT_OPT_GET_USER_AGENT,
 	GIT_OPT_ENABLE_OFS_DELTA,
 	GIT_OPT_ENABLE_SYNCHRONOUS_OBJECT_CREATION,
+	GIT_OPT_GET_WINDOWS_SHAREMODE,
+	GIT_OPT_SET_WINDOWS_SHAREMODE,
 } git_libgit2_opt_t;
 
 /**
@@ -284,6 +286,16 @@ typedef enum {
  *		> - `user_agent` is the value that will be delivered as the
  *		>   User-Agent header on HTTP requests.
  *
+ *	* opts(GIT_OPT_SET_WINDOWS_SHAREMODE, DWORD value)
+ *
+ *		> Set the default share modes on Windows for opening files.
+ *		> This can be used to add FILE_SHARE_DELETE.
+ *		> The Windows default is: FILE_SHARE_READ | FILE_SHARE_WRITE.
+ *
+ *	* opts(GIT_OPT_GET_WINDOWS_SHAREMODE, DWORD *value)
+ *
+ *		> Get the default share modes on Windows for opening files.
+ *
  *	* opts(GIT_OPT_ENABLE_STRICT_OBJECT_CREATION, int enabled)
  *
  *		> Enable strict input validation when creating new objects

diff --git a/src/settings.c b/src/settings.c
@@ -231,6 +231,24 @@ int git_libgit2_opts(int key, ...)
 		git_object__synchronous_writing = (va_arg(ap, int) != 0);
 		break;
 
+	case GIT_OPT_GET_WINDOWS_SHAREMODE:
+#ifdef GIT_WIN32
+		*(va_arg(ap, DWORD *)) = git_posix_w32__windows_sharemode;
+#else
+		giterr_set(GITERR_INVALID, "cannot set windows share mode on non Windows builds");
+		error = -1;
+#endif
+		break;
+
+	case GIT_OPT_SET_WINDOWS_SHAREMODE:
+#ifdef GIT_WIN32
+		git_posix_w32__windows_sharemode = (va_arg(ap, DWORD) & (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE));
+#else
+		giterr_set(GITERR_INVALID, "cannot set windows share mode on non Windows builds");
+		error = -1;
+#endif
+		break;
+
 	default:
 		giterr_set(GITERR_INVALID, "invalid option key");
 		error = -1;

diff --git a/src/win32/posix.h b/src/win32/posix.h
@@ -14,6 +14,8 @@
 #include "utf-conv.h"
 #include "dir.h"
 
+extern DWORD git_posix_w32__windows_sharemode;
+
 typedef SOCKET GIT_SOCKET;
 
 #define p_lseek(f,n,w) _lseeki64(f, n, w)

diff --git a/src/win32/posix_w32.c b/src/win32/posix_w32.c
@@ -18,6 +18,8 @@
 #include <fcntl.h>
 #include <ws2tcpip.h>
 
+DWORD git_posix_w32__windows_sharemode = FILE_SHARE_READ | FILE_SHARE_WRITE;
+
 #ifndef FILE_NAME_NORMALIZED
 # define FILE_NAME_NORMALIZED 0
 #endif
@@ -26,15 +28,6 @@
 #define IO_REPARSE_TAG_SYMLINK (0xA000000CL)
 #endif
 
-/* Options which we always provide to _wopen.
- *
- * _O_BINARY - Raw access; no translation of CR or LF characters
- * _O_NOINHERIT - Do not mark the created handle as inheritable by child processes.
- *    The Windows default is 'not inheritable', but the CRT's default (following
- *    POSIX convention) is 'inheritable'. We have no desire for our handles to be
- *    inheritable on Windows, so specify the flag to get default behavior back. */
-#define STANDARD_OPEN_FLAGS (_O_BINARY | _O_NOINHERIT)
-
 /* Allowable mode bits on Win32.  Using mode bits that are not supported on
  * Win32 (eg S_IRWXU) is generally ignored, but Wine warns loudly about it
  * so we simply remove them.
@@ -285,32 +278,101 @@ int p_symlink(const char *old, const char *new)
 int p_open(const char *path, int flags, ...)
 {
 	git_win32_path buf;
-	mode_t mode = 0;
+	HANDLE handle;
+	DWORD desired_access;
+	DWORD creation_disposition;
+	DWORD flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
+	int osfhandle_flags = 0;
 
 	if (git_win32_path_from_utf8(buf, path) < 0)
 		return -1;
 
 	if (flags & O_CREAT) {
 		va_list arg_list;
+		mode_t mode = 0;
 
 		va_start(arg_list, flags);
 		mode = (mode_t)va_arg(arg_list, int);
 		va_end(arg_list);
+
+		if (!(mode & _S_IWRITE))
+			flags_and_attributes = FILE_ATTRIBUTE_READONLY;
 	}
 
-	return _wopen(buf, flags | STANDARD_OPEN_FLAGS, mode & WIN32_MODE_MASK);
-}
+	/* we only support _O_BINARY and set this by default */
+	if (flags & (_O_TEXT | _O_WTEXT | _O_U16TEXT | _O_U8TEXT)) {
+		errno = EINVAL;
+		return -1;
+	}
 
-int p_creat(const char *path, mode_t mode)
-{
-	git_win32_path buf;
+	/* currently unsupported */
+	if (flags & (_O_SEQUENTIAL | _O_RANDOM | _O_TEMPORARY | _O_SHORT_LIVED)) {
+		errno = EINVAL;
+		return -1;
+	}
 
-	if (git_win32_path_from_utf8(buf, path) < 0)
+	switch (flags & (_O_RDONLY | _O_WRONLY | _O_RDWR | _O_APPEND)) {
+	case _O_RDONLY:
+		desired_access = GENERIC_READ;
+		osfhandle_flags = _O_RDONLY;
+		break;
+	case _O_WRONLY | _O_APPEND:
+		osfhandle_flags = _O_APPEND;
+	case _O_WRONLY:
+		desired_access = GENERIC_WRITE;
+		break;
+	case _O_RDWR | _O_APPEND:
+		osfhandle_flags = _O_APPEND;
+	case _O_RDWR:
+		desired_access = GENERIC_READ | GENERIC_WRITE;
+		break;
+	default:
+		/* invalid or unsupported flag (combination) */
+		errno = EINVAL;
 		return -1;
+	}
 
-	return _wopen(buf,
-		_O_WRONLY | _O_CREAT | _O_TRUNC | STANDARD_OPEN_FLAGS,
-		mode & WIN32_MODE_MASK);
+	switch (flags & (_O_CREAT | _O_EXCL | _O_TRUNC)) {
+	case 0:
+		creation_disposition = OPEN_EXISTING;
+		break;
+
+	case _O_CREAT:
+		creation_disposition = OPEN_ALWAYS;
+		break;
+
+	case _O_CREAT | _O_TRUNC:
+		creation_disposition = CREATE_ALWAYS;
+		break;
+
+	case _O_CREAT | _O_EXCL:
+	case _O_CREAT | _O_TRUNC | _O_EXCL:
+		creation_disposition = CREATE_NEW;
+		break;
+
+	case _O_TRUNC:
+		creation_disposition = TRUNCATE_EXISTING;
+		break;
+
+	default:
+		/* _O_EXCL required O_CREAT to be set, IIRC this is no error in MSVC implementaton */
+		errno = EINVAL;
+		return  -1;
+	}
+
+	handle = CreateFileW(buf, desired_access, git_posix_w32__windows_sharemode, NULL, creation_disposition, flags_and_attributes, 0);
+	if (handle == INVALID_HANDLE_VALUE)
+	{
+		_dosmaperr(GetLastError());
+		return -1;
+	}
+
+	return _open_osfhandle((intptr_t)handle, osfhandle_flags);
+}
+
+int p_creat(const char *path, mode_t mode)
+{
+	return p_open(path, _O_WRONLY | _O_CREAT | _O_TRUNC, mode);
 }
 
 int p_getcwd(char *buffer_out, size_t size)

diff --git a/src/win32/w32_dosmaperr.c b/src/win32/w32_dosmaperr.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ *
+ * struct doserrmap: auto-generated from winerror.h and errno.h using undoc'd _dosmaperr.
+ * Inspired by ReactOS reactos\sdk\lib\crt\stdlib\doserrmap.h
+ */
+
+
+#if !defined(_MSC_VER) || _MSC_VER >= 1900
+#include <errno.h>
+#include <winerror.h>
+
+static const struct {
+	unsigned long	winerr;
+	int				en;
+} doserrors[] =
+{	{ ERROR_FILE_NOT_FOUND, ENOENT },
+	{ ERROR_PATH_NOT_FOUND, ENOENT },
+	{ ERROR_TOO_MANY_OPEN_FILES, EMFILE },
+	{ ERROR_ACCESS_DENIED, EACCES },
+	{ ERROR_INVALID_HANDLE, EBADF },
+	{ ERROR_ARENA_TRASHED, ENOMEM },
+	{ ERROR_NOT_ENOUGH_MEMORY, ENOMEM },
+	{ ERROR_INVALID_BLOCK, ENOMEM },
+	{ ERROR_BAD_ENVIRONMENT, E2BIG },
+	{ ERROR_BAD_FORMAT, ENOEXEC },
+	{ ERROR_INVALID_DRIVE, ENOENT },
+	{ ERROR_CURRENT_DIRECTORY, EACCES },
+	{ ERROR_NOT_SAME_DEVICE, EXDEV },
+	{ ERROR_NO_MORE_FILES, ENOENT },
+	{ ERROR_WRITE_PROTECT, EACCES },
+	{ ERROR_BAD_UNIT, EACCES },
+	{ ERROR_NOT_READY, EACCES },
+	{ ERROR_BAD_COMMAND, EACCES },
+	{ ERROR_CRC, EACCES },
+	{ ERROR_BAD_LENGTH, EACCES },
+	{ ERROR_SEEK, EACCES },
+	{ ERROR_NOT_DOS_DISK, EACCES },
+	{ ERROR_SECTOR_NOT_FOUND, EACCES },
+	{ ERROR_OUT_OF_PAPER, EACCES },
+	{ ERROR_WRITE_FAULT, EACCES },
+	{ ERROR_READ_FAULT, EACCES },
+	{ ERROR_GEN_FAILURE, EACCES },
+	{ ERROR_SHARING_VIOLATION, EACCES },
+	{ ERROR_LOCK_VIOLATION, EACCES },
+	{ ERROR_WRONG_DISK, EACCES },
+	{ ERROR_SHARING_BUFFER_EXCEEDED, EACCES },
+	{ ERROR_BAD_NETPATH, ENOENT },
+	{ ERROR_NETWORK_ACCESS_DENIED, EACCES },
+	{ ERROR_BAD_NET_NAME, ENOENT },
+	{ ERROR_FILE_EXISTS, EEXIST },
+	{ ERROR_CANNOT_MAKE, EACCES },
+	{ ERROR_FAIL_I24, EACCES },
+	{ ERROR_NO_PROC_SLOTS, EAGAIN },
+	{ ERROR_DRIVE_LOCKED, EACCES },
+	{ ERROR_BROKEN_PIPE, EPIPE },
+	{ ERROR_DISK_FULL, ENOSPC },
+	{ ERROR_INVALID_TARGET_HANDLE, EBADF },
+	{ ERROR_WAIT_NO_CHILDREN, ECHILD },
+	{ ERROR_CHILD_NOT_COMPLETE, ECHILD },
+	{ ERROR_DIRECT_ACCESS_HANDLE, EBADF },
+	{ ERROR_SEEK_ON_DEVICE, EACCES },
+	{ ERROR_DIR_NOT_EMPTY, ENOTEMPTY },
+	{ ERROR_NOT_LOCKED, EACCES },
+	{ ERROR_BAD_PATHNAME, ENOENT },
+	{ ERROR_MAX_THRDS_REACHED, EAGAIN },
+	{ ERROR_LOCK_FAILED, EACCES },
+	{ ERROR_ALREADY_EXISTS, EEXIST },
+	{ ERROR_INVALID_STARTING_CODESEG, ENOEXEC },
+	{ ERROR_INVALID_STACKSEG, ENOEXEC },
+	{ ERROR_INVALID_MODULETYPE, ENOEXEC },
+	{ ERROR_INVALID_EXE_SIGNATURE, ENOEXEC },
+	{ ERROR_EXE_MARKED_INVALID, ENOEXEC },
+	{ ERROR_BAD_EXE_FORMAT, ENOEXEC },
+	{ ERROR_ITERATED_DATA_EXCEEDS_64k, ENOEXEC },
+	{ ERROR_INVALID_MINALLOCSIZE, ENOEXEC },
+	{ ERROR_DYNLINK_FROM_INVALID_RING, ENOEXEC },
+	{ ERROR_IOPL_NOT_ENABLED, ENOEXEC },
+	{ ERROR_INVALID_SEGDPL, ENOEXEC },
+	{ ERROR_AUTODATASEG_EXCEEDS_64k, ENOEXEC },
+	{ ERROR_RING2SEG_MUST_BE_MOVABLE, ENOEXEC },
+	{ ERROR_RELOC_CHAIN_XEEDS_SEGLIM, ENOEXEC },
+	{ ERROR_INFLOOP_IN_RELOC_CHAIN, ENOEXEC },
+	{ ERROR_FILENAME_EXCED_RANGE, ENOENT },
+	{ ERROR_NESTING_NOT_ALLOWED, EAGAIN },
+	{ ERROR_NOT_ENOUGH_QUOTA, ENOMEM }
+};
+
+void _dosmaperr(unsigned long e)
+{
+	unsigned int i;
+	if (e == 0)
+	{
+		errno = 0;
+		return;
+	}
+
+	for (i = 0; i < sizeof(doserrors) / sizeof(doserrors[0]); ++i)
+	{
+		if (doserrors[i].winerr == e)
+		{
+			errno = doserrors[i].en;
+			return;
+		}
+	}
+
+	errno = EINVAL;
+}
+#endif