compat/mingw.c

   1 #include "../git-compat-util.h"
   2 #include "win32.h"
   3 #include <conio.h>
   4 #include "../strbuf.h"
   5 #include "../cache.h"
   6
   7 unsigned int _CRT_fmode = _O_BINARY;
   8
   9 int err_win_to_posix(DWORD winerr)
  10 {
  11         int error = ENOSYS;
  12         switch(winerr) {
  13         case ERROR_ACCESS_DENIED: error = EACCES; break;
  14         case ERROR_ACCOUNT_DISABLED: error = EACCES; break;
  15         case ERROR_ACCOUNT_RESTRICTION: error = EACCES; break;
  16         case ERROR_ALREADY_ASSIGNED: error = EBUSY; break;
  17         case ERROR_ALREADY_EXISTS: error = EEXIST; break;
  18         case ERROR_ARITHMETIC_OVERFLOW: error = ERANGE; break;
  19         case ERROR_BAD_COMMAND: error = EIO; break;
  20         case ERROR_BAD_DEVICE: error = ENODEV; break;
  21         case ERROR_BAD_DRIVER_LEVEL: error = ENXIO; break;
  22         case ERROR_BAD_EXE_FORMAT: error = ENOEXEC; break;
  23         case ERROR_BAD_FORMAT: error = ENOEXEC; break;
  24         case ERROR_BAD_LENGTH: error = EINVAL; break;
  25         case ERROR_BAD_PATHNAME: error = ENOENT; break;
  26         case ERROR_BAD_PIPE: error = EPIPE; break;
  27         case ERROR_BAD_UNIT: error = ENODEV; break;
  28         case ERROR_BAD_USERNAME: error = EINVAL; break;
  29         case ERROR_BROKEN_PIPE: error = EPIPE; break;
  30         case ERROR_BUFFER_OVERFLOW: error = ENAMETOOLONG; break;
  31         case ERROR_BUSY: error = EBUSY; break;
  32         case ERROR_BUSY_DRIVE: error = EBUSY; break;
  33         case ERROR_CALL_NOT_IMPLEMENTED: error = ENOSYS; break;
  34         case ERROR_CANNOT_MAKE: error = EACCES; break;
  35         case ERROR_CANTOPEN: error = EIO; break;
  36         case ERROR_CANTREAD: error = EIO; break;
  37         case ERROR_CANTWRITE: error = EIO; break;
  38         case ERROR_CRC: error = EIO; break;
  39         case ERROR_CURRENT_DIRECTORY: error = EACCES; break;
  40         case ERROR_DEVICE_IN_USE: error = EBUSY; break;
  41         case ERROR_DEV_NOT_EXIST: error = ENODEV; break;
  42         case ERROR_DIRECTORY: error = EINVAL; break;
  43         case ERROR_DIR_NOT_EMPTY: error = ENOTEMPTY; break;
  44         case ERROR_DISK_CHANGE: error = EIO; break;
  45         case ERROR_DISK_FULL: error = ENOSPC; break;
  46         case ERROR_DRIVE_LOCKED: error = EBUSY; break;
  47         case ERROR_ENVVAR_NOT_FOUND: error = EINVAL; break;
  48         case ERROR_EXE_MARKED_INVALID: error = ENOEXEC; break;
  49         case ERROR_FILENAME_EXCED_RANGE: error = ENAMETOOLONG; break;
  50         case ERROR_FILE_EXISTS: error = EEXIST; break;
  51         case ERROR_FILE_INVALID: error = ENODEV; break;
  52         case ERROR_FILE_NOT_FOUND: error = ENOENT; break;
  53         case ERROR_GEN_FAILURE: error = EIO; break;
  54         case ERROR_HANDLE_DISK_FULL: error = ENOSPC; break;
  55         case ERROR_INSUFFICIENT_BUFFER: error = ENOMEM; break;
  56         case ERROR_INVALID_ACCESS: error = EACCES; break;
  57         case ERROR_INVALID_ADDRESS: error = EFAULT; break;
  58         case ERROR_INVALID_BLOCK: error = EFAULT; break;
  59         case ERROR_INVALID_DATA: error = EINVAL; break;
  60         case ERROR_INVALID_DRIVE: error = ENODEV; break;
  61         case ERROR_INVALID_EXE_SIGNATURE: error = ENOEXEC; break;
  62         case ERROR_INVALID_FLAGS: error = EINVAL; break;
  63         case ERROR_INVALID_FUNCTION: error = ENOSYS; break;
  64         case ERROR_INVALID_HANDLE: error = EBADF; break;
  65         case ERROR_INVALID_LOGON_HOURS: error = EACCES; break;
  66         case ERROR_INVALID_NAME: error = EINVAL; break;
  67         case ERROR_INVALID_OWNER: error = EINVAL; break;
  68         case ERROR_INVALID_PARAMETER: error = EINVAL; break;
  69         case ERROR_INVALID_PASSWORD: error = EPERM; break;
  70         case ERROR_INVALID_PRIMARY_GROUP: error = EINVAL; break;
  71         case ERROR_INVALID_SIGNAL_NUMBER: error = EINVAL; break;
  72         case ERROR_INVALID_TARGET_HANDLE: error = EIO; break;
  73         case ERROR_INVALID_WORKSTATION: error = EACCES; break;
  74         case ERROR_IO_DEVICE: error = EIO; break;
  75         case ERROR_IO_INCOMPLETE: error = EINTR; break;
  76         case ERROR_LOCKED: error = EBUSY; break;
  77         case ERROR_LOCK_VIOLATION: error = EACCES; break;
  78         case ERROR_LOGON_FAILURE: error = EACCES; break;
  79         case ERROR_MAPPED_ALIGNMENT: error = EINVAL; break;
  80         case ERROR_META_EXPANSION_TOO_LONG: error = E2BIG; break;
  81         case ERROR_MORE_DATA: error = EPIPE; break;
  82         case ERROR_NEGATIVE_SEEK: error = ESPIPE; break;
  83         case ERROR_NOACCESS: error = EFAULT; break;
  84         case ERROR_NONE_MAPPED: error = EINVAL; break;
  85         case ERROR_NOT_ENOUGH_MEMORY: error = ENOMEM; break;
  86         case ERROR_NOT_READY: error = EAGAIN; break;
  87         case ERROR_NOT_SAME_DEVICE: error = EXDEV; break;
  88         case ERROR_NO_DATA: error = EPIPE; break;
  89         case ERROR_NO_MORE_SEARCH_HANDLES: error = EIO; break;
  90         case ERROR_NO_PROC_SLOTS: error = EAGAIN; break;
  91         case ERROR_NO_SUCH_PRIVILEGE: error = EACCES; break;
  92         case ERROR_OPEN_FAILED: error = EIO; break;
  93         case ERROR_OPEN_FILES: error = EBUSY; break;
  94         case ERROR_OPERATION_ABORTED: error = EINTR; break;
  95         case ERROR_OUTOFMEMORY: error = ENOMEM; break;
  96         case ERROR_PASSWORD_EXPIRED: error = EACCES; break;
  97         case ERROR_PATH_BUSY: error = EBUSY; break;
  98         case ERROR_PATH_NOT_FOUND: error = ENOENT; break;
  99         case ERROR_PIPE_BUSY: error = EBUSY; break;
 100         case ERROR_PIPE_CONNECTED: error = EPIPE; break;
 101         case ERROR_PIPE_LISTENING: error = EPIPE; break;
 102         case ERROR_PIPE_NOT_CONNECTED: error = EPIPE; break;
 103         case ERROR_PRIVILEGE_NOT_HELD: error = EACCES; break;
 104         case ERROR_READ_FAULT: error = EIO; break;
 105         case ERROR_SEEK: error = EIO; break;
 106         case ERROR_SEEK_ON_DEVICE: error = ESPIPE; break;
 107         case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break;
 108         case ERROR_SHARING_VIOLATION: error = EACCES; break;
 109         case ERROR_STACK_OVERFLOW: error = ENOMEM; break;
 110         case ERROR_SWAPERROR: error = ENOENT; break;
 111         case ERROR_TOO_MANY_MODULES: error = EMFILE; break;
 112         case ERROR_TOO_MANY_OPEN_FILES: error = EMFILE; break;
 113         case ERROR_UNRECOGNIZED_MEDIA: error = ENXIO; break;
 114         case ERROR_UNRECOGNIZED_VOLUME: error = ENODEV; break;
 115         case ERROR_WAIT_NO_CHILDREN: error = ECHILD; break;
 116         case ERROR_WRITE_FAULT: error = EIO; break;
 117         case ERROR_WRITE_PROTECT: error = EROFS; break;
 118         }
 119         return error;
 120 }
 121
 122 static int make_hidden(const char *path)
 123 {
 124         DWORD attribs = GetFileAttributes(path);
 125         if (SetFileAttributes(path, FILE_ATTRIBUTE_HIDDEN | attribs))
 126                 return 0;
 127         errno = err_win_to_posix(GetLastError());
 128         return -1;
 129 }
 130
 131 void mingw_mark_as_git_dir(const char *dir)
 132 {
 133         if (hide_dotfiles != HIDE_DOTFILES_FALSE && make_hidden(dir))
 134                 warning("Failed to make '%s' hidden", dir);
 135         git_config_set("core.hideDotFiles",
 136                 hide_dotfiles == HIDE_DOTFILES_FALSE ? "false" :
 137                 (hide_dotfiles == HIDE_DOTFILES_DOTGITONLY ?
 138                  "dotGitOnly" : "true"));
 139 }
 140
 141 #undef mkdir
 142 int mingw_mkdir(const char *path, int mode)
 143 {
 144         int ret = mkdir(path);
 145         if (!ret && hide_dotfiles == HIDE_DOTFILES_TRUE) {
 146                 /*
 147                  * In Windows a file or dir starting with a dot is not
 148                  * automatically hidden. So lets mark it as hidden when
 149                  * such a directory is created.
 150                  */
 151                 const char *start = basename((char*)path);
 152                 if (*start == '.')
 153                         return make_hidden(path);
 154         }
 155         return ret;
 156 }
 157
 158 #undef open
 159 int mingw_open (const char *filename, int oflags, ...)
 160 {
 161         va_list args;
 162         unsigned mode;
 163         int fd;
 164
 165         va_start(args, oflags);
 166         mode = va_arg(args, int);
 167         va_end(args);
 168
 169         if (filename && !strcmp(filename, "/dev/null"))
 170                 filename = "nul";
 171
 172         fd = open(filename, oflags, mode);
 173
 174         if (fd < 0 && (oflags & O_CREAT) && errno == EACCES) {
 175                 DWORD attrs = GetFileAttributes(filename);
 176                 if (attrs != INVALID_FILE_ATTRIBUTES && (attrs & FILE_ATTRIBUTE_DIRECTORY))
 177                         errno = EISDIR;
 178         }
 179         if ((oflags & O_CREAT) && fd >= 0 &&
 180             hide_dotfiles == HIDE_DOTFILES_TRUE) {
 181                 /*
 182                  * In Windows a file or dir starting with a dot is not
 183                  * automatically hidden. So lets mark it as hidden when
 184                  * such a file is created.
 185                  */
 186                 const char *start = basename((char*)filename);
 187                 if (*start == '.' && make_hidden(filename))
 188                         warning("Could not mark '%s' as hidden.", filename);
 189         }
 190         return fd;
 191 }
 192
 193 #undef write
 194 ssize_t mingw_write(int fd, const void *buf, size_t count)
 195 {
 196         /*
 197          * While write() calls to a file on a local disk are translated
 198          * into WriteFile() calls with a maximum size of 64KB on Windows
 199          * XP and 256KB on Vista, no such cap is placed on writes to
 200          * files over the network on Windows XP.  Unfortunately, there
 201          * seems to be a limit of 32MB-28KB on X64 and 64MB-32KB on x86;
 202          * bigger writes fail on Windows XP.
 203          * So we cap to a nice 31MB here to avoid write failures over
 204          * the net without changing the number of WriteFile() calls in
 205          * the local case.
 206          */
 207         return write(fd, buf, min(count, 31 * 1024 * 1024));
 208 }
 209
 210 #undef fopen
 211 FILE *mingw_fopen (const char *filename, const char *otype)
 212 {
 213         int hide = 0;
 214         FILE *file;
 215         if (hide_dotfiles == HIDE_DOTFILES_TRUE &&
 216             basename((char*)filename)[0] == '.')
 217                 hide = access(filename, F_OK);
 218         if (filename && !strcmp(filename, "/dev/null"))
 219                 filename = "nul";
 220         file = fopen(filename, otype);
 221         if (file && hide && make_hidden(filename))
 222                 warning("Could not mark '%s' as hidden.", filename);
 223         return file;
 224 }
 225
 226 #undef freopen
 227 FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream)
 228 {
 229         int hide = 0;
 230         FILE *file;
 231         if (hide_dotfiles == HIDE_DOTFILES_TRUE &&
 232             basename((char*)filename)[0] == '.')
 233                 hide = access(filename, F_OK);
 234         if (filename && !strcmp(filename, "/dev/null"))
 235                 filename = "nul";
 236         file = freopen(filename, otype, stream);
 237         if (file && hide && make_hidden(filename))
 238                 warning("Could not mark '%s' as hidden.", filename);
 239         return file;
 240 }
 241
 242 /*
 243  * The unit of FILETIME is 100-nanoseconds since January 1, 1601, UTC.
 244  * Returns the 100-nanoseconds ("hekto nanoseconds") since the epoch.
 245  */
 246 static inline long long filetime_to_hnsec(const FILETIME *ft)
 247 {
 248         long long winTime = ((long long)ft->dwHighDateTime << 32) + ft->dwLowDateTime;
 249         /* Windows to Unix Epoch conversion */
 250         return winTime - 116444736000000000LL;
 251 }
 252
 253 static inline time_t filetime_to_time_t(const FILETIME *ft)
 254 {
 255         return (time_t)(filetime_to_hnsec(ft) / 10000000);
 256 }
 257
 258 /* We keep the do_lstat code in a separate function to avoid recursion.
 259  * When a path ends with a slash, the stat will fail with ENOENT. In
 260  * this case, we strip the trailing slashes and stat again.
 261  *
 262  * If follow is true then act like stat() and report on the link
 263  * target. Otherwise report on the link itself.
 264  */
 265 static int do_lstat(int follow, const char *file_name, struct stat *buf)
 266 {
 267         WIN32_FILE_ATTRIBUTE_DATA fdata;
 268
 269         if (!(errno = get_file_attr(file_name, &fdata))) {
 270                 buf->st_ino = 0;
 271                 buf->st_gid = 0;
 272                 buf->st_uid = 0;
 273                 buf->st_nlink = 1;
 274                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 275                 buf->st_size = fdata.nFileSizeLow |
 276                         (((off_t)fdata.nFileSizeHigh)<<32);
 277                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 278                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 279                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 280                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 281                 if (fdata.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) {
 282                         WIN32_FIND_DATAA findbuf;
 283                         HANDLE handle = FindFirstFileA(file_name, &findbuf);
 284                         if (handle != INVALID_HANDLE_VALUE) {
 285                                 if ((findbuf.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) &&
 286                                                 (findbuf.dwReserved0 == IO_REPARSE_TAG_SYMLINK)) {
 287                                         if (follow) {
 288                                                 char buffer[MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
 289                                                 buf->st_size = readlink(file_name, buffer, MAXIMUM_REPARSE_DATA_BUFFER_SIZE);
 290                                         } else {
 291                                                 buf->st_mode = S_IFLNK;
 292                                         }
 293                                         buf->st_mode |= S_IREAD;
 294                                         if (!(findbuf.dwFileAttributes & FILE_ATTRIBUTE_READONLY))
 295                                                 buf->st_mode |= S_IWRITE;
 296                                 }
 297                                 FindClose(handle);
 298                         }
 299                 }
 300                 return 0;
 301         }
 302         return -1;
 303 }
 304
 305 /* We provide our own lstat/fstat functions, since the provided
 306  * lstat/fstat functions are so slow. These stat functions are
 307  * tailored for Git's usage (read: fast), and are not meant to be
 308  * complete. Note that Git stat()s are redirected to mingw_lstat()
 309  * too, since Windows doesn't really handle symlinks that well.
 310  */
 311 static int do_stat_internal(int follow, const char *file_name, struct stat *buf)
 312 {
 313         int namelen;
 314         static char alt_name[PATH_MAX];
 315
 316         if (!do_lstat(follow, file_name, buf))
 317                 return 0;
 318
 319         /* if file_name ended in a '/', Windows returned ENOENT;
 320          * try again without trailing slashes
 321          */
 322         if (errno != ENOENT)
 323                 return -1;
 324
 325         namelen = strlen(file_name);
 326         if (namelen && file_name[namelen-1] != '/')
 327                 return -1;
 328         while (namelen && file_name[namelen-1] == '/')
 329                 --namelen;
 330         if (!namelen || namelen >= PATH_MAX)
 331                 return -1;
 332
 333         memcpy(alt_name, file_name, namelen);
 334         alt_name[namelen] = 0;
 335         return do_lstat(follow, alt_name, buf);
 336 }
 337
 338 int mingw_lstat(const char *file_name, struct stat *buf)
 339 {
 340         return do_stat_internal(0, file_name, buf);
 341 }
 342 int mingw_stat(const char *file_name, struct stat *buf)
 343 {
 344         return do_stat_internal(1, file_name, buf);
 345 }
 346
 347 #undef fstat
 348 int mingw_fstat(int fd, struct stat *buf)
 349 {
 350         HANDLE fh = (HANDLE)_get_osfhandle(fd);
 351         BY_HANDLE_FILE_INFORMATION fdata;
 352
 353         if (fh == INVALID_HANDLE_VALUE) {
 354                 errno = EBADF;
 355                 return -1;
 356         }
 357         /* direct non-file handles to MS's fstat() */
 358         if (GetFileType(fh) != FILE_TYPE_DISK)
 359                 return _fstati64(fd, buf);
 360
 361         if (GetFileInformationByHandle(fh, &fdata)) {
 362                 buf->st_ino = 0;
 363                 buf->st_gid = 0;
 364                 buf->st_uid = 0;
 365                 buf->st_nlink = 1;
 366                 buf->st_mode = file_attr_to_st_mode(fdata.dwFileAttributes);
 367                 buf->st_size = fdata.nFileSizeLow |
 368                         (((off_t)fdata.nFileSizeHigh)<<32);
 369                 buf->st_dev = buf->st_rdev = 0; /* not used by Git */
 370                 buf->st_atime = filetime_to_time_t(&(fdata.ftLastAccessTime));
 371                 buf->st_mtime = filetime_to_time_t(&(fdata.ftLastWriteTime));
 372                 buf->st_ctime = filetime_to_time_t(&(fdata.ftCreationTime));
 373                 return 0;
 374         }
 375         errno = EBADF;
 376         return -1;
 377 }
 378
 379 static inline void time_t_to_filetime(time_t t, FILETIME *ft)
 380 {
 381         long long winTime = t * 10000000LL + 116444736000000000LL;
 382         ft->dwLowDateTime = winTime;
 383         ft->dwHighDateTime = winTime >> 32;
 384 }
 385
 386 int mingw_utime (const char *file_name, const struct utimbuf *times)
 387 {
 388         FILETIME mft, aft;
 389         int fh, rc;
 390
 391         /* must have write permission */
 392         DWORD attrs = GetFileAttributes(file_name);
 393         if (attrs != INVALID_FILE_ATTRIBUTES &&
 394             (attrs & FILE_ATTRIBUTE_READONLY)) {
 395                 /* ignore errors here; open() will report them */
 396                 SetFileAttributes(file_name, attrs & ~FILE_ATTRIBUTE_READONLY);
 397         }
 398
 399         if ((fh = open(file_name, O_RDWR | O_BINARY)) < 0) {
 400                 rc = -1;
 401                 goto revert_attrs;
 402         }
 403
 404         if (times) {
 405                 time_t_to_filetime(times->modtime, &mft);
 406                 time_t_to_filetime(times->actime, &aft);
 407         } else {
 408                 GetSystemTimeAsFileTime(&mft);
 409                 aft = mft;
 410         }
 411         if (!SetFileTime((HANDLE)_get_osfhandle(fh), NULL, &aft, &mft)) {
 412                 errno = EINVAL;
 413                 rc = -1;
 414         } else
 415                 rc = 0;
 416         close(fh);
 417
 418 revert_attrs:
 419         if (attrs != INVALID_FILE_ATTRIBUTES &&
 420             (attrs & FILE_ATTRIBUTE_READONLY)) {
 421                 /* ignore errors again */
 422                 SetFileAttributes(file_name, attrs);
 423         }
 424         return rc;
 425 }
 426
 427 unsigned int sleep (unsigned int seconds)
 428 {
 429         Sleep(seconds*1000);
 430         return 0;
 431 }
 432
 433 int mkstemp(char *template)
 434 {
 435         char *filename = mktemp(template);
 436         if (filename == NULL)
 437                 return -1;
 438         return open(filename, O_RDWR | O_CREAT, 0600);
 439 }
 440
 441 int gettimeofday(struct timeval *tv, void *tz)
 442 {
 443         FILETIME ft;
 444         long long hnsec;
 445
 446         GetSystemTimeAsFileTime(&ft);
 447         hnsec = filetime_to_hnsec(&ft);
 448         tv->tv_sec = hnsec / 10000000;
 449         tv->tv_usec = (hnsec % 10000000) / 10;
 450         return 0;
 451 }
 452
 453 int pipe(int filedes[2])
 454 {
 455         HANDLE h[2];
 456
 457         /* this creates non-inheritable handles */
 458         if (!CreatePipe(&h[0], &h[1], NULL, 8192)) {
 459                 errno = err_win_to_posix(GetLastError());
 460                 return -1;
 461         }
 462         filedes[0] = _open_osfhandle((int)h[0], O_NOINHERIT);
 463         if (filedes[0] < 0) {
 464                 CloseHandle(h[0]);
 465                 CloseHandle(h[1]);
 466                 return -1;
 467         }
 468         filedes[1] = _open_osfhandle((int)h[1], O_NOINHERIT);
 469         if (filedes[0] < 0) {
 470                 close(filedes[0]);
 471                 CloseHandle(h[1]);
 472                 return -1;
 473         }
 474         return 0;
 475 }
 476
 477 int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
 478 {
 479         int i, pending;
 480
 481         if (timeout >= 0) {
 482                 if (nfds == 0) {
 483                         Sleep(timeout);
 484                         return 0;
 485                 }
 486                 return errno = EINVAL, error("poll timeout not supported");
 487         }
 488
 489         /* When there is only one fd to wait for, then we pretend that
 490          * input is available and let the actual wait happen when the
 491          * caller invokes read().
 492          */
 493         if (nfds == 1) {
 494                 if (!(ufds[0].events & POLLIN))
 495                         return errno = EINVAL, error("POLLIN not set");
 496                 ufds[0].revents = POLLIN;
 497                 return 0;
 498         }
 499
 500 repeat:
 501         pending = 0;
 502         for (i = 0; i < nfds; i++) {
 503                 DWORD avail = 0;
 504                 HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd);
 505                 if (h == INVALID_HANDLE_VALUE)
 506                         return -1;      /* errno was set */
 507
 508                 if (!(ufds[i].events & POLLIN))
 509                         return errno = EINVAL, error("POLLIN not set");
 510
 511                 /* this emulation works only for pipes */
 512                 if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) {
 513                         int err = GetLastError();
 514                         if (err == ERROR_BROKEN_PIPE) {
 515                                 ufds[i].revents = POLLHUP;
 516                                 pending++;
 517                         } else {
 518                                 errno = EINVAL;
 519                                 return error("PeekNamedPipe failed,"
 520                                         " GetLastError: %u", err);
 521                         }
 522                 } else if (avail) {
 523                         ufds[i].revents = POLLIN;
 524                         pending++;
 525                 } else
 526                         ufds[i].revents = 0;
 527         }
 528         if (!pending) {
 529                 /* The only times that we spin here is when the process
 530                  * that is connected through the pipes is waiting for
 531                  * its own input data to become available. But since
 532                  * the process (pack-objects) is itself CPU intensive,
 533                  * it will happily pick up the time slice that we are
 534                  * relinquishing here.
 535                  */
 536                 Sleep(0);
 537                 goto repeat;
 538         }
 539         return 0;
 540 }
 541
 542 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 543 {
 544         /* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 545         memcpy(result, gmtime(timep), sizeof(struct tm));
 546         return result;
 547 }
 548
 549 struct tm *localtime_r(const time_t *timep, struct tm *result)
 550 {
 551         /* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
 552         memcpy(result, localtime(timep), sizeof(struct tm));
 553         return result;
 554 }
 555
 556 #undef getcwd
 557 char *mingw_getcwd(char *pointer, int len)
 558 {
 559         int i;
 560         char *ret = getcwd(pointer, len);
 561         if (!ret)
 562                 return ret;
 563         for (i = 0; pointer[i]; i++)
 564                 if (pointer[i] == '\\')
 565                         pointer[i] = '/';
 566         return ret;
 567 }
 568
 569 #undef getenv
 570 char *mingw_getenv(const char *name)
 571 {
 572         char *result = getenv(name);
 573         if (!result && !strcmp(name, "TMPDIR")) {
 574                 /* on Windows it is TMP and TEMP */
 575                 result = getenv("TMP");
 576                 if (!result)
 577                         result = getenv("TEMP");
 578         }
 579         return result;
 580 }
 581
 582 /*
 583  * See http://msdn2.microsoft.com/en-us/library/17w5ykft(vs.71).aspx
 584  * (Parsing C++ Command-Line Arguments)
 585  */
 586 static const char *quote_arg(const char *arg)
 587 {
 588         /* count chars to quote */
 589         int len = 0, n = 0;
 590         int force_quotes = 0;
 591         char *q, *d;
 592         const char *p = arg;
 593         if (!*p) force_quotes = 1;
 594         while (*p) {
 595                 if (isspace(*p) || *p == '*' || *p == '?' || *p == '{' || *p == '\'')
 596                         force_quotes = 1;
 597                 else if (*p == '"')
 598                         n++;
 599                 else if (*p == '\\') {
 600                         int count = 0;
 601                         while (*p == '\\') {
 602                                 count++;
 603                                 p++;
 604                                 len++;
 605                         }
 606                         if (*p == '"')
 607                                 n += count*2 + 1;
 608                         continue;
 609                 }
 610                 len++;
 611                 p++;
 612         }
 613         if (!force_quotes && n == 0)
 614                 return arg;
 615
 616         /* insert \ where necessary */
 617         d = q = xmalloc(len+n+3);
 618         *d++ = '"';
 619         while (*arg) {
 620                 if (*arg == '"')
 621                         *d++ = '\\';
 622                 else if (*arg == '\\') {
 623                         int count = 0;
 624                         while (*arg == '\\') {
 625                                 count++;
 626                                 *d++ = *arg++;
 627                         }
 628                         if (*arg == '"') {
 629                                 while (count-- > 0)
 630                                         *d++ = '\\';
 631                                 *d++ = '\\';
 632                         }
 633                 }
 634                 *d++ = *arg++;
 635         }
 636         *d++ = '"';
 637         *d++ = 0;
 638         return q;
 639 }
 640
 641 static const char *parse_interpreter(const char *cmd)
 642 {
 643         static char buf[100];
 644         char *p, *opt;
 645         int n, fd;
 646
 647         /* don't even try a .exe */
 648         n = strlen(cmd);
 649         if (n >= 4 && !strcasecmp(cmd+n-4, ".exe"))
 650                 return NULL;
 651
 652         fd = open(cmd, O_RDONLY);
 653         if (fd < 0)
 654                 return NULL;
 655         n = read(fd, buf, sizeof(buf)-1);
 656         close(fd);
 657         if (n < 4)      /* at least '#!/x' and not error */
 658                 return NULL;
 659
 660         if (buf[0] != '#' || buf[1] != '!')
 661                 return NULL;
 662         buf[n] = '\0';
 663         p = buf + strcspn(buf, "\r\n");
 664         if (!*p)
 665                 return NULL;
 666
 667         *p = '\0';
 668         if (!(p = strrchr(buf+2, '/')) && !(p = strrchr(buf+2, '\\')))
 669                 return NULL;
 670         /* strip options */
 671         if ((opt = strchr(p+1, ' ')))
 672                 *opt = '\0';
 673         return p+1;
 674 }
 675
 676 /*
 677  * Splits the PATH into parts.
 678  */
 679 static char **get_path_split(void)
 680 {
 681         char *p, **path, *envpath = getenv("PATH");
 682         int i, n = 0;
 683
 684         if (!envpath || !*envpath)
 685                 return NULL;
 686
 687         envpath = xstrdup(envpath);
 688         p = envpath;
 689         while (p) {
 690                 char *dir = p;
 691                 p = strchr(p, ';');
 692                 if (p) *p++ = '\0';
 693                 if (*dir) {     /* not earlier, catches series of ; */
 694                         ++n;
 695                 }
 696         }
 697         if (!n)
 698                 return NULL;
 699
 700         path = xmalloc((n+1)*sizeof(char *));
 701         p = envpath;
 702         i = 0;
 703         do {
 704                 if (*p)
 705                         path[i++] = xstrdup(p);
 706                 p = p+strlen(p)+1;
 707         } while (i < n);
 708         path[i] = NULL;
 709
 710         free(envpath);
 711
 712         return path;
 713 }
 714
 715 static void free_path_split(char **path)
 716 {
 717         char **p = path;
 718
 719         if (!path)
 720                 return;
 721
 722         while (*p)
 723                 free(*p++);
 724         free(path);
 725 }
 726
 727 /*
 728  * exe_only means that we only want to detect .exe files, but not scripts
 729  * (which do not have an extension)
 730  */
 731 static char *lookup_prog(const char *dir, const char *cmd, int isexe, int exe_only)
 732 {
 733         char path[MAX_PATH];
 734         snprintf(path, sizeof(path), "%s/%s.exe", dir, cmd);
 735
 736         if (!isexe && access(path, F_OK) == 0)
 737                 return xstrdup(path);
 738         path[strlen(path)-4] = '\0';
 739         if ((!exe_only || isexe) && access(path, F_OK) == 0)
 740                 if (!(GetFileAttributes(path) & FILE_ATTRIBUTE_DIRECTORY))
 741                         return xstrdup(path);
 742         return NULL;
 743 }
 744
 745 /*
 746  * Determines the absolute path of cmd using the split path in path.
 747  * If cmd contains a slash or backslash, no lookup is performed.
 748  */
 749 static char *path_lookup(const char *cmd, char **path, int exe_only)
 750 {
 751         char *prog = NULL;
 752         int len = strlen(cmd);
 753         int isexe = len >= 4 && !strcasecmp(cmd+len-4, ".exe");
 754
 755         if (strchr(cmd, '/') || strchr(cmd, '\\'))
 756                 prog = xstrdup(cmd);
 757
 758         while (!prog && *path)
 759                 prog = lookup_prog(*path++, cmd, isexe, exe_only);
 760
 761         return prog;
 762 }
 763
 764 static int env_compare(const void *a, const void *b)
 765 {
 766         char *const *ea = a;
 767         char *const *eb = b;
 768         return strcasecmp(*ea, *eb);
 769 }
 770
 771 static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 772                               const char *dir,
 773                               int prepend_cmd, int fhin, int fhout, int fherr)
 774 {
 775         STARTUPINFO si;
 776         PROCESS_INFORMATION pi;
 777         struct strbuf envblk, args;
 778         unsigned flags;
 779         BOOL ret;
 780
 781         /* Determine whether or not we are associated to a console */
 782         HANDLE cons = CreateFile("CONOUT$", GENERIC_WRITE,
 783                         FILE_SHARE_WRITE, NULL, OPEN_EXISTING,
 784                         FILE_ATTRIBUTE_NORMAL, NULL);
 785         if (cons == INVALID_HANDLE_VALUE) {
 786                 /* There is no console associated with this process.
 787                  * Since the child is a console process, Windows
 788                  * would normally create a console window. But
 789                  * since we'll be redirecting std streams, we do
 790                  * not need the console.
 791                  * It is necessary to use DETACHED_PROCESS
 792                  * instead of CREATE_NO_WINDOW to make ssh
 793                  * recognize that it has no console.
 794                  */
 795                 flags = DETACHED_PROCESS;
 796         } else {
 797                 /* There is already a console. If we specified
 798                  * DETACHED_PROCESS here, too, Windows would
 799                  * disassociate the child from the console.
 800                  * The same is true for CREATE_NO_WINDOW.
 801                  * Go figure!
 802                  */
 803                 flags = 0;
 804                 CloseHandle(cons);
 805         }
 806         memset(&si, 0, sizeof(si));
 807         si.cb = sizeof(si);
 808         si.dwFlags = STARTF_USESTDHANDLES;
 809         si.hStdInput = (HANDLE) _get_osfhandle(fhin);
 810         si.hStdOutput = (HANDLE) _get_osfhandle(fhout);
 811         si.hStdError = (HANDLE) _get_osfhandle(fherr);
 812
 813         /* concatenate argv, quoting args as we go */
 814         strbuf_init(&args, 0);
 815         if (prepend_cmd) {
 816                 char *quoted = (char *)quote_arg(cmd);
 817                 strbuf_addstr(&args, quoted);
 818                 if (quoted != cmd)
 819                         free(quoted);
 820         }
 821         for (; *argv; argv++) {
 822                 char *quoted = (char *)quote_arg(*argv);
 823                 if (*args.buf)
 824                         strbuf_addch(&args, ' ');
 825                 strbuf_addstr(&args, quoted);
 826                 if (quoted != *argv)
 827                         free(quoted);
 828         }
 829
 830         if (env) {
 831                 int count = 0;
 832                 char **e, **sorted_env;
 833
 834                 for (e = env; *e; e++)
 835                         count++;
 836
 837                 /* environment must be sorted */
 838                 sorted_env = xmalloc(sizeof(*sorted_env) * (count + 1));
 839                 memcpy(sorted_env, env, sizeof(*sorted_env) * (count + 1));
 840                 qsort(sorted_env, count, sizeof(*sorted_env), env_compare);
 841
 842                 strbuf_init(&envblk, 0);
 843                 for (e = sorted_env; *e; e++) {
 844                         strbuf_addstr(&envblk, *e);
 845                         strbuf_addch(&envblk, '\0');
 846                 }
 847                 free(sorted_env);
 848         }
 849
 850         memset(&pi, 0, sizeof(pi));
 851         ret = CreateProcess(cmd, args.buf, NULL, NULL, TRUE, flags,
 852                 env ? envblk.buf : NULL, dir, &si, &pi);
 853
 854         if (env)
 855                 strbuf_release(&envblk);
 856         strbuf_release(&args);
 857
 858         if (!ret) {
 859                 errno = ENOENT;
 860                 return -1;
 861         }
 862         CloseHandle(pi.hThread);
 863         return (pid_t)pi.hProcess;
 864 }
 865
 866 static pid_t mingw_spawnve(const char *cmd, const char **argv, char **env,
 867                            int prepend_cmd)
 868 {
 869         return mingw_spawnve_fd(cmd, argv, env, NULL, prepend_cmd, 0, 1, 2);
 870 }
 871
 872 pid_t mingw_spawnvpe(const char *cmd, const char **argv, char **env,
 873                      const char *dir,
 874                      int fhin, int fhout, int fherr)
 875 {
 876         pid_t pid;
 877         char **path = get_path_split();
 878         char *prog = path_lookup(cmd, path, 0);
 879
 880         if (!prog) {
 881                 errno = ENOENT;
 882                 pid = -1;
 883         }
 884         else {
 885                 const char *interpr = parse_interpreter(prog);
 886
 887                 if (interpr) {
 888                         const char *argv0 = argv[0];
 889                         char *iprog = path_lookup(interpr, path, 1);
 890                         argv[0] = prog;
 891                         if (!iprog) {
 892                                 errno = ENOENT;
 893                                 pid = -1;
 894                         }
 895                         else {
 896                                 pid = mingw_spawnve_fd(iprog, argv, env, dir, 1,
 897                                                        fhin, fhout, fherr);
 898                                 free(iprog);
 899                         }
 900                         argv[0] = argv0;
 901                 }
 902                 else
 903                         pid = mingw_spawnve_fd(prog, argv, env, dir, 0,
 904                                                fhin, fhout, fherr);
 905                 free(prog);
 906         }
 907         free_path_split(path);
 908         return pid;
 909 }
 910
 911 static int try_shell_exec(const char *cmd, char *const *argv, char **env)
 912 {
 913         const char *interpr = parse_interpreter(cmd);
 914         char **path;
 915         char *prog;
 916         int pid = 0;
 917
 918         if (!interpr)
 919                 return 0;
 920         path = get_path_split();
 921         prog = path_lookup(interpr, path, 1);
 922         if (prog) {
 923                 int argc = 0;
 924                 const char **argv2;
 925                 while (argv[argc]) argc++;
 926                 argv2 = xmalloc(sizeof(*argv) * (argc+1));
 927                 argv2[0] = (char *)cmd; /* full path to the script file */
 928                 memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
 929                 pid = mingw_spawnve(prog, argv2, env, 1);
 930                 if (pid >= 0) {
 931                         int status;
 932                         if (waitpid(pid, &status, 0) < 0)
 933                                 status = 255;
 934                         exit(status);
 935                 }
 936                 pid = 1;        /* indicate that we tried but failed */
 937                 free(prog);
 938                 free(argv2);
 939         }
 940         free_path_split(path);
 941         return pid;
 942 }
 943
 944 static void mingw_execve(const char *cmd, char *const *argv, char *const *env)
 945 {
 946         /* check if git_command is a shell script */
 947         if (!try_shell_exec(cmd, argv, (char **)env)) {
 948                 int pid, status;
 949
 950                 pid = mingw_spawnve(cmd, (const char **)argv, (char **)env, 0);
 951                 if (pid < 0)
 952                         return;
 953                 if (waitpid(pid, &status, 0) < 0)
 954                         status = 255;
 955                 exit(status);
 956         }
 957 }
 958
 959 void mingw_execvp(const char *cmd, char *const *argv)
 960 {
 961         char **path = get_path_split();
 962         char *prog = path_lookup(cmd, path, 0);
 963
 964         if (prog) {
 965                 mingw_execve(prog, argv, environ);
 966                 free(prog);
 967         } else
 968                 errno = ENOENT;
 969
 970         free_path_split(path);
 971 }
 972
 973 static char **copy_environ(void)
 974 {
 975         char **env;
 976         int i = 0;
 977         while (environ[i])
 978                 i++;
 979         env = xmalloc((i+1)*sizeof(*env));
 980         for (i = 0; environ[i]; i++)
 981                 env[i] = xstrdup(environ[i]);
 982         env[i] = NULL;
 983         return env;
 984 }
 985
 986 void free_environ(char **env)
 987 {
 988         int i;
 989         for (i = 0; env[i]; i++)
 990                 free(env[i]);
 991         free(env);
 992 }
 993
 994 static int lookup_env(char **env, const char *name, size_t nmln)
 995 {
 996         int i;
 997
 998         for (i = 0; env[i]; i++) {
 999                 if (0 == strncmp(env[i], name, nmln)
1000                     && '=' == env[i][nmln])
1001                         /* matches */
1002                         return i;
1003         }
1004         return -1;
1005 }
1006
1007 /*
1008  * If name contains '=', then sets the variable, otherwise it unsets it
1009  */
1010 static char **env_setenv(char **env, const char *name)
1011 {
1012         char *eq = strchrnul(name, '=');
1013         int i = lookup_env(env, name, eq-name);
1014
1015         if (i < 0) {
1016                 if (*eq) {
1017                         for (i = 0; env[i]; i++)
1018                                 ;
1019                         env = xrealloc(env, (i+2)*sizeof(*env));
1020                         env[i] = xstrdup(name);
1021                         env[i+1] = NULL;
1022                 }
1023         }
1024         else {
1025                 free(env[i]);
1026                 if (*eq)
1027                         env[i] = xstrdup(name);
1028                 else
1029                         for (; env[i]; i++)
1030                                 env[i] = env[i+1];
1031         }
1032         return env;
1033 }
1034
1035 /*
1036  * Copies global environ and adjusts variables as specified by vars.
1037  */
1038 char **make_augmented_environ(const char *const *vars)
1039 {
1040         char **env = copy_environ();
1041
1042         while (*vars)
1043                 env = env_setenv(env, *vars++);
1044         return env;
1045 }
1046
1047 /*
1048  * Note, this isn't a complete replacement for getaddrinfo. It assumes
1049  * that service contains a numerical port, or that it it is null. It
1050  * does a simple search using gethostbyname, and returns one IPv4 host
1051  * if one was found.
1052  */
1053 static int WSAAPI getaddrinfo_stub(const char *node, const char *service,
1054                                    const struct addrinfo *hints,
1055                                    struct addrinfo **res)
1056 {
1057         struct hostent *h = gethostbyname(node);
1058         struct addrinfo *ai;
1059         struct sockaddr_in *sin;
1060
1061         if (!h)
1062                 return WSAGetLastError();
1063
1064         ai = xmalloc(sizeof(struct addrinfo));
1065         *res = ai;
1066         ai->ai_flags = 0;
1067         ai->ai_family = AF_INET;
1068         ai->ai_socktype = hints->ai_socktype;
1069         switch (hints->ai_socktype) {
1070         case SOCK_STREAM:
1071                 ai->ai_protocol = IPPROTO_TCP;
1072                 break;
1073         case SOCK_DGRAM:
1074                 ai->ai_protocol = IPPROTO_UDP;
1075                 break;
1076         default:
1077                 ai->ai_protocol = 0;
1078                 break;
1079         }
1080         ai->ai_addrlen = sizeof(struct sockaddr_in);
1081         ai->ai_canonname = strdup(h->h_name);
1082
1083         sin = xmalloc(ai->ai_addrlen);
1084         memset(sin, 0, ai->ai_addrlen);
1085         sin->sin_family = AF_INET;
1086         if (service)
1087                 sin->sin_port = htons(atoi(service));
1088         sin->sin_addr = *(struct in_addr *)h->h_addr;
1089         ai->ai_addr = (struct sockaddr *)sin;
1090         ai->ai_next = 0;
1091         return 0;
1092 }
1093
1094 static void WSAAPI freeaddrinfo_stub(struct addrinfo *res)
1095 {
1096         free(res->ai_canonname);
1097         free(res->ai_addr);
1098         free(res);
1099 }
1100
1101 static int WSAAPI getnameinfo_stub(const struct sockaddr *sa, socklen_t salen,
1102                                    char *host, DWORD hostlen,
1103                                    char *serv, DWORD servlen, int flags)
1104 {
1105         const struct sockaddr_in *sin = (const struct sockaddr_in *)sa;
1106         if (sa->sa_family != AF_INET)
1107                 return EAI_FAMILY;
1108         if (!host && !serv)
1109                 return EAI_NONAME;
1110
1111         if (host && hostlen > 0) {
1112                 struct hostent *ent = NULL;
1113                 if (!(flags & NI_NUMERICHOST))
1114                         ent = gethostbyaddr((const char *)&sin->sin_addr,
1115                                             sizeof(sin->sin_addr), AF_INET);
1116
1117                 if (ent)
1118                         snprintf(host, hostlen, "%s", ent->h_name);
1119                 else if (flags & NI_NAMEREQD)
1120                         return EAI_NONAME;
1121                 else
1122                         snprintf(host, hostlen, "%s", inet_ntoa(sin->sin_addr));
1123         }
1124
1125         if (serv && servlen > 0) {
1126                 struct servent *ent = NULL;
1127                 if (!(flags & NI_NUMERICSERV))
1128                         ent = getservbyport(sin->sin_port,
1129                                             flags & NI_DGRAM ? "udp" : "tcp");
1130
1131                 if (ent)
1132                         snprintf(serv, servlen, "%s", ent->s_name);
1133                 else
1134                         snprintf(serv, servlen, "%d", ntohs(sin->sin_port));
1135         }
1136
1137         return 0;
1138 }
1139
1140 static HMODULE ipv6_dll = NULL;
1141 static void (WSAAPI *ipv6_freeaddrinfo)(struct addrinfo *res);
1142 static int (WSAAPI *ipv6_getaddrinfo)(const char *node, const char *service,
1143                                       const struct addrinfo *hints,
1144                                       struct addrinfo **res);
1145 static int (WSAAPI *ipv6_getnameinfo)(const struct sockaddr *sa, socklen_t salen,
1146                                       char *host, DWORD hostlen,
1147                                       char *serv, DWORD servlen, int flags);
1148 /*
1149  * gai_strerror is an inline function in the ws2tcpip.h header, so we
1150  * don't need to try to load that one dynamically.
1151  */
1152
1153 static void socket_cleanup(void)
1154 {
1155         WSACleanup();
1156         if (ipv6_dll)
1157                 FreeLibrary(ipv6_dll);
1158         ipv6_dll = NULL;
1159         ipv6_freeaddrinfo = freeaddrinfo_stub;
1160         ipv6_getaddrinfo = getaddrinfo_stub;
1161         ipv6_getnameinfo = getnameinfo_stub;
1162 }
1163
1164 static void ensure_socket_initialization(void)
1165 {
1166         WSADATA wsa;
1167         static int initialized = 0;
1168         const char *libraries[] = { "ws2_32.dll", "wship6.dll", NULL };
1169         const char **name;
1170
1171         if (initialized)
1172                 return;
1173
1174         if (WSAStartup(MAKEWORD(2,2), &wsa))
1175                 die("unable to initialize winsock subsystem, error %d",
1176                         WSAGetLastError());
1177
1178         for (name = libraries; *name; name++) {
1179                 ipv6_dll = LoadLibrary(*name);
1180                 if (!ipv6_dll)
1181                         continue;
1182
1183                 ipv6_freeaddrinfo = (void (WSAAPI *)(struct addrinfo *))
1184                         GetProcAddress(ipv6_dll, "freeaddrinfo");
1185                 ipv6_getaddrinfo = (int (WSAAPI *)(const char *, const char *,
1186                                                    const struct addrinfo *,
1187                                                    struct addrinfo **))
1188                         GetProcAddress(ipv6_dll, "getaddrinfo");
1189                 ipv6_getnameinfo = (int (WSAAPI *)(const struct sockaddr *,
1190                                                    socklen_t, char *, DWORD,
1191                                                    char *, DWORD, int))
1192                         GetProcAddress(ipv6_dll, "getnameinfo");
1193                 if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
1194                         FreeLibrary(ipv6_dll);
1195                         ipv6_dll = NULL;
1196                 } else
1197                         break;
1198         }
1199         if (!ipv6_freeaddrinfo || !ipv6_getaddrinfo || !ipv6_getnameinfo) {
1200                 ipv6_freeaddrinfo = freeaddrinfo_stub;
1201                 ipv6_getaddrinfo = getaddrinfo_stub;
1202                 ipv6_getnameinfo = getnameinfo_stub;
1203         }
1204
1205         atexit(socket_cleanup);
1206         initialized = 1;
1207 }
1208
1209 #undef gethostbyname
1210 struct hostent *mingw_gethostbyname(const char *host)
1211 {
1212         ensure_socket_initialization();
1213         return gethostbyname(host);
1214 }
1215
1216 void mingw_freeaddrinfo(struct addrinfo *res)
1217 {
1218         ipv6_freeaddrinfo(res);
1219 }
1220
1221 int mingw_getaddrinfo(const char *node, const char *service,
1222                       const struct addrinfo *hints, struct addrinfo **res)
1223 {
1224         ensure_socket_initialization();
1225         return ipv6_getaddrinfo(node, service, hints, res);
1226 }
1227
1228 int mingw_getnameinfo(const struct sockaddr *sa, socklen_t salen,
1229                       char *host, DWORD hostlen, char *serv, DWORD servlen,
1230                       int flags)
1231 {
1232         ensure_socket_initialization();
1233         return ipv6_getnameinfo(sa, salen, host, hostlen, serv, servlen, flags);
1234 }
1235
1236 int mingw_socket(int domain, int type, int protocol)
1237 {
1238         int sockfd;
1239         SOCKET s = WSASocket(domain, type, protocol, NULL, 0, 0);
1240         if (s == INVALID_SOCKET) {
1241                 /*
1242                  * WSAGetLastError() values are regular BSD error codes
1243                  * biased by WSABASEERR.
1244                  * However, strerror() does not know about networking
1245                  * specific errors, which are values beginning at 38 or so.
1246                  * Therefore, we choose to leave the biased error code
1247                  * in errno so that _if_ someone looks up the code somewhere,
1248                  * then it is at least the number that are usually listed.
1249                  */
1250                 errno = WSAGetLastError();
1251                 return -1;
1252         }
1253         /* convert into a file descriptor */
1254         if ((sockfd = _open_osfhandle(s, O_RDWR|O_BINARY)) < 0) {
1255                 closesocket(s);
1256                 return error("unable to make a socket file descriptor: %s",
1257                         strerror(errno));
1258         }
1259         return sockfd;
1260 }
1261
1262 #undef connect
1263 int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz)
1264 {
1265         SOCKET s = (SOCKET)_get_osfhandle(sockfd);
1266         return connect(s, sa, sz);
1267 }
1268
1269 #undef rename
1270 int mingw_rename(const char *pold, const char *pnew)
1271 {
1272         DWORD attrs, gle;
1273         int tries = 0;
1274         static const int delay[] = { 0, 1, 10, 20, 40 };
1275
1276         /*
1277          * Try native rename() first to get errno right.
1278          * It is based on MoveFile(), which cannot overwrite existing files.
1279          */
1280         if (!rename(pold, pnew))
1281                 return 0;
1282         if (errno != EEXIST)
1283                 return -1;
1284 repeat:
1285         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
1286                 return 0;
1287         /* TODO: translate more errors */
1288         gle = GetLastError();
1289         if (gle == ERROR_ACCESS_DENIED &&
1290             (attrs = GetFileAttributes(pnew)) != INVALID_FILE_ATTRIBUTES) {
1291                 if (attrs & FILE_ATTRIBUTE_DIRECTORY) {
1292                         errno = EISDIR;
1293                         return -1;
1294                 }
1295                 if ((attrs & FILE_ATTRIBUTE_READONLY) &&
1296                     SetFileAttributes(pnew, attrs & ~FILE_ATTRIBUTE_READONLY)) {
1297                         if (MoveFileEx(pold, pnew, MOVEFILE_REPLACE_EXISTING))
1298                                 return 0;
1299                         gle = GetLastError();
1300                         /* revert file attributes on failure */
1301                         SetFileAttributes(pnew, attrs);
1302                 }
1303         }
1304         if (tries < ARRAY_SIZE(delay) && gle == ERROR_ACCESS_DENIED) {
1305                 /*
1306                  * We assume that some other process had the source or
1307                  * destination file open at the wrong moment and retry.
1308                  * In order to give the other process a higher chance to
1309                  * complete its operation, we give up our time slice now.
1310                  * If we have to retry again, we do sleep a bit.
1311                  */
1312                 Sleep(delay[tries]);
1313                 tries++;
1314                 goto repeat;
1315         }
1316         errno = EACCES;
1317         return -1;
1318 }
1319
1320 /*
1321  * Note that this doesn't return the actual pagesize, but
1322  * the allocation granularity. If future Windows specific git code
1323  * needs the real getpagesize function, we need to find another solution.
1324  */
1325 int mingw_getpagesize(void)
1326 {
1327         SYSTEM_INFO si;
1328         GetSystemInfo(&si);
1329         return si.dwAllocationGranularity;
1330 }
1331
1332 struct passwd *getpwuid(int uid)
1333 {
1334         static char user_name[100];
1335         static struct passwd p;
1336
1337         DWORD len = sizeof(user_name);
1338         if (!GetUserName(user_name, &len))
1339                 return NULL;
1340         p.pw_name = user_name;
1341         p.pw_gecos = "unknown";
1342         p.pw_dir = NULL;
1343         return &p;
1344 }
1345
1346 static HANDLE timer_event;
1347 static HANDLE timer_thread;
1348 static int timer_interval;
1349 static int one_shot;
1350 static sig_handler_t timer_fn = SIG_DFL;
1351
1352 /* The timer works like this:
1353  * The thread, ticktack(), is a trivial routine that most of the time
1354  * only waits to receive the signal to terminate. The main thread tells
1355  * the thread to terminate by setting the timer_event to the signalled
1356  * state.
1357  * But ticktack() interrupts the wait state after the timer's interval
1358  * length to call the signal handler.
1359  */
1360
1361 static unsigned __stdcall ticktack(void *dummy)
1362 {
1363         while (WaitForSingleObject(timer_event, timer_interval) == WAIT_TIMEOUT) {
1364                 if (timer_fn == SIG_DFL)
1365                         die("Alarm");
1366                 if (timer_fn != SIG_IGN)
1367                         timer_fn(SIGALRM);
1368                 if (one_shot)
1369                         break;
1370         }
1371         return 0;
1372 }
1373
1374 static int start_timer_thread(void)
1375 {
1376         timer_event = CreateEvent(NULL, FALSE, FALSE, NULL);
1377         if (timer_event) {
1378                 timer_thread = (HANDLE) _beginthreadex(NULL, 0, ticktack, NULL, 0, NULL);
1379                 if (!timer_thread )
1380                         return errno = ENOMEM,
1381                                 error("cannot start timer thread");
1382         } else
1383                 return errno = ENOMEM,
1384                         error("cannot allocate resources for timer");
1385         return 0;
1386 }
1387
1388 static void stop_timer_thread(void)
1389 {
1390         if (timer_event)
1391                 SetEvent(timer_event);  /* tell thread to terminate */
1392         if (timer_thread) {
1393                 int rc = WaitForSingleObject(timer_thread, 1000);
1394                 if (rc == WAIT_TIMEOUT)
1395                         error("timer thread did not terminate timely");
1396                 else if (rc != WAIT_OBJECT_0)
1397                         error("waiting for timer thread failed: %lu",
1398                               GetLastError());
1399                 CloseHandle(timer_thread);
1400         }
1401         if (timer_event)
1402                 CloseHandle(timer_event);
1403         timer_event = NULL;
1404         timer_thread = NULL;
1405 }
1406
1407 static inline int is_timeval_eq(const struct timeval *i1, const struct timeval *i2)
1408 {
1409         return i1->tv_sec == i2->tv_sec && i1->tv_usec == i2->tv_usec;
1410 }
1411
1412 int setitimer(int type, struct itimerval *in, struct itimerval *out)
1413 {
1414         static const struct timeval zero;
1415         static int atexit_done;
1416
1417         if (out != NULL)
1418                 return errno = EINVAL,
1419                         error("setitimer param 3 != NULL not implemented");
1420         if (!is_timeval_eq(&in->it_interval, &zero) &&
1421             !is_timeval_eq(&in->it_interval, &in->it_value))
1422                 return errno = EINVAL,
1423                         error("setitimer: it_interval must be zero or eq it_value");
1424
1425         if (timer_thread)
1426                 stop_timer_thread();
1427
1428         if (is_timeval_eq(&in->it_value, &zero) &&
1429             is_timeval_eq(&in->it_interval, &zero))
1430                 return 0;
1431
1432         timer_interval = in->it_value.tv_sec * 1000 + in->it_value.tv_usec / 1000;
1433         one_shot = is_timeval_eq(&in->it_interval, &zero);
1434         if (!atexit_done) {
1435                 atexit(stop_timer_thread);
1436                 atexit_done = 1;
1437         }
1438         return start_timer_thread();
1439 }
1440
1441 int sigaction(int sig, struct sigaction *in, struct sigaction *out)
1442 {
1443         if (sig != SIGALRM)
1444                 return errno = EINVAL,
1445                         error("sigaction only implemented for SIGALRM");
1446         if (out != NULL)
1447                 return errno = EINVAL,
1448                         error("sigaction: param 3 != NULL not implemented");
1449
1450         timer_fn = in->sa_handler;
1451         return 0;
1452 }
1453
1454 #undef signal
1455 sig_handler_t mingw_signal(int sig, sig_handler_t handler)
1456 {
1457         sig_handler_t old = timer_fn;
1458         if (sig != SIGALRM)
1459                 return signal(sig, handler);
1460         timer_fn = handler;
1461         return old;
1462 }
1463
1464 static const char *make_backslash_path(const char *path)
1465 {
1466         static char buf[PATH_MAX + 1];
1467         char *c;
1468
1469         if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
1470                 die("Too long path: %.*s", 60, path);
1471
1472         for (c = buf; *c; c++) {
1473                 if (*c == '/')
1474                         *c = '\\';
1475         }
1476         return buf;
1477 }
1478
1479 void mingw_open_html(const char *unixpath)
1480 {
1481         const char *htmlpath = make_backslash_path(unixpath);
1482         typedef HINSTANCE (WINAPI *T)(HWND, const char *,
1483                         const char *, const char *, const char *, INT);
1484         T ShellExecute;
1485         HMODULE shell32;
1486         int r;
1487
1488         shell32 = LoadLibrary("shell32.dll");
1489         if (!shell32)
1490                 die("cannot load shell32.dll");
1491         ShellExecute = (T)GetProcAddress(shell32, "ShellExecuteA");
1492         if (!ShellExecute)
1493                 die("cannot run browser");
1494
1495         printf("Launching default browser to display HTML ...\n");
1496         r = (int)ShellExecute(NULL, "open", htmlpath, NULL, "\\", SW_SHOWNORMAL);
1497         FreeLibrary(shell32);
1498         /* see the MSDN documentation referring to the result codes here */
1499         if (r <= 32) {
1500                 die("failed to launch browser for %.*s", MAX_PATH, unixpath);
1501         }
1502 }
1503
1504 int link(const char *oldpath, const char *newpath)
1505 {
1506         typedef BOOL (WINAPI *T)(const char*, const char*, LPSECURITY_ATTRIBUTES);
1507         static T create_hard_link = NULL;
1508         if (!create_hard_link) {
1509                 create_hard_link = (T) GetProcAddress(
1510                         GetModuleHandle("kernel32.dll"), "CreateHardLinkA");
1511                 if (!create_hard_link)
1512                         create_hard_link = (T)-1;
1513         }
1514         if (create_hard_link == (T)-1) {
1515                 errno = ENOSYS;
1516                 return -1;
1517         }
1518         if (!create_hard_link(newpath, oldpath, NULL)) {
1519                 errno = err_win_to_posix(GetLastError());
1520                 return -1;
1521         }
1522         return 0;
1523 }
1524
1525 char *getpass(const char *prompt)
1526 {
1527         struct strbuf buf = STRBUF_INIT;
1528
1529         fputs(prompt, stderr);
1530         for (;;) {
1531                 char c = _getch();
1532                 if (c == '\r' || c == '\n')
1533                         break;
1534                 strbuf_addch(&buf, c);
1535         }
1536         fputs("\n", stderr);
1537         return strbuf_detach(&buf, NULL);
1538 }
1539
1540 #ifndef NO_MINGW_REPLACE_READDIR
1541 /* MinGW readdir implementation to avoid extra lstats for Git */
1542 struct mingw_DIR
1543 {
1544         struct _finddata_t      dd_dta;         /* disk transfer area for this dir */
1545         struct mingw_dirent     dd_dir;         /* Our own implementation, including d_type */
1546         long                    dd_handle;      /* _findnext handle */
1547         int                     dd_stat;        /* 0 = next entry to read is first entry, -1 = off the end, positive = 0 based index of next entry */
1548         char                    dd_name[1];     /* given path for dir with search pattern (struct is extended) */
1549 };
1550
1551 struct dirent *mingw_readdir(DIR *dir)
1552 {
1553         WIN32_FIND_DATAA buf;
1554         HANDLE handle;
1555         struct mingw_DIR *mdir = (struct mingw_DIR*)dir;
1556
1557         if (!dir->dd_handle) {
1558                 errno = EBADF; /* No set_errno for mingw */
1559                 return NULL;
1560         }
1561
1562         if (dir->dd_handle == (long)INVALID_HANDLE_VALUE && dir->dd_stat == 0)
1563         {
1564                 DWORD lasterr;
1565                 handle = FindFirstFileA(dir->dd_name, &buf);
1566                 lasterr = GetLastError();
1567                 dir->dd_handle = (long)handle;
1568                 if (handle == INVALID_HANDLE_VALUE && (lasterr != ERROR_NO_MORE_FILES)) {
1569                         errno = err_win_to_posix(lasterr);
1570                         return NULL;
1571                 }
1572         } else if (dir->dd_handle == (long)INVALID_HANDLE_VALUE) {
1573                 return NULL;
1574         } else if (!FindNextFileA((HANDLE)dir->dd_handle, &buf)) {
1575                 DWORD lasterr = GetLastError();
1576                 FindClose((HANDLE)dir->dd_handle);
1577                 dir->dd_handle = (long)INVALID_HANDLE_VALUE;
1578                 /* POSIX says you shouldn't set errno when readdir can't
1579                    find any more files; so, if another error we leave it set. */
1580                 if (lasterr != ERROR_NO_MORE_FILES)
1581                         errno = err_win_to_posix(lasterr);
1582                 return NULL;
1583         }
1584
1585         /* We get here if `buf' contains valid data.  */
1586         strcpy(dir->dd_dir.d_name, buf.cFileName);
1587         ++dir->dd_stat;
1588
1589         /* Set file type, based on WIN32_FIND_DATA */
1590         mdir->dd_dir.d_type = 0;
1591         if (buf.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
1592                 mdir->dd_dir.d_type |= DT_DIR;
1593         else
1594                 mdir->dd_dir.d_type |= DT_REG;
1595
1596         return (struct dirent*)&dir->dd_dir;
1597 }
1598 #endif // !NO_MINGW_REPLACE_READDIR