compat/winansi.c

   1 /*
   2  * Copyright 2008 Peter Harris <git@peter.is-a-geek.org>
   3  */
   4
   5 #undef NOGDI
   6
   7 /*
   8  * Including the appropriate header file for RtlGenRandom causes MSVC to see a
   9  * redefinition of types in an incompatible way when including headers below.
  10  */
  11 #undef HAVE_RTLGENRANDOM
  12 #include "../git-compat-util.h"
  13 #include <wingdi.h>
  14 #include <winreg.h>
  15 #include "win32.h"
  16 #include "win32/lazyload.h"
  17
  18 static int fd_is_interactive[3] = { 0, 0, 0 };
  19 #define FD_CONSOLE 0x1
  20 #define FD_SWAPPED 0x2
  21 #define FD_MSYS    0x4
  22
  23 /*
  24  ANSI codes used by git: m, K
  25
  26  This file is git-specific. Therefore, this file does not attempt
  27  to implement any codes that are not used by git.
  28 */
  29
  30 static HANDLE console;
  31 static WORD plain_attr;
  32 static WORD attr;
  33 static int negative;
  34 static int non_ascii_used = 0;
  35 static HANDLE hthread, hread, hwrite;
  36 static HANDLE hconsole1, hconsole2;
  37
  38 #ifdef __MINGW32__
  39 #if !defined(__MINGW64_VERSION_MAJOR) || __MINGW64_VERSION_MAJOR < 5
  40 typedef struct _CONSOLE_FONT_INFOEX {
  41         ULONG cbSize;
  42         DWORD nFont;
  43         COORD dwFontSize;
  44         UINT FontFamily;
  45         UINT FontWeight;
  46         WCHAR FaceName[LF_FACESIZE];
  47 } CONSOLE_FONT_INFOEX, *PCONSOLE_FONT_INFOEX;
  48 #endif
  49 #endif
  50
  51 static void warn_if_raster_font(void)
  52 {
  53         DWORD fontFamily = 0;
  54         DECLARE_PROC_ADDR(kernel32.dll, BOOL, GetCurrentConsoleFontEx,
  55                         HANDLE, BOOL, PCONSOLE_FONT_INFOEX);
  56
  57         /* don't bother if output was ascii only */
  58         if (!non_ascii_used)
  59                 return;
  60
  61         /* GetCurrentConsoleFontEx is available since Vista */
  62         if (INIT_PROC_ADDR(GetCurrentConsoleFontEx)) {
  63                 CONSOLE_FONT_INFOEX cfi;
  64                 cfi.cbSize = sizeof(cfi);
  65                 if (GetCurrentConsoleFontEx(console, 0, &cfi))
  66                         fontFamily = cfi.FontFamily;
  67         } else {
  68                 /* pre-Vista: check default console font in registry */
  69                 HKEY hkey;
  70                 if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_CURRENT_USER, "Console",
  71                                 0, KEY_READ, &hkey)) {
  72                         DWORD size = sizeof(fontFamily);
  73                         RegQueryValueExA(hkey, "FontFamily", NULL, NULL,
  74                                         (LPVOID) &fontFamily, &size);
  75                         RegCloseKey(hkey);
  76                 }
  77         }
  78
  79         if (!(fontFamily & TMPF_TRUETYPE)) {
  80                 const wchar_t *msg = L"\nWarning: Your console font probably "
  81                         L"doesn\'t support Unicode. If you experience strange "
  82                         L"characters in the output, consider switching to a "
  83                         L"TrueType font such as Consolas!\n";
  84                 DWORD dummy;
  85                 WriteConsoleW(console, msg, wcslen(msg), &dummy, NULL);
  86         }
  87 }
  88
  89 static int is_console(int fd)
  90 {
  91         CONSOLE_SCREEN_BUFFER_INFO sbi;
  92         DWORD mode;
  93         HANDLE hcon;
  94
  95         static int initialized = 0;
  96
  97         /* get OS handle of the file descriptor */
  98         hcon = (HANDLE) _get_osfhandle(fd);
  99         if (hcon == INVALID_HANDLE_VALUE)
 100                 return 0;
 101
 102         /* check if its a device (i.e. console, printer, serial port) */
 103         if (GetFileType(hcon) != FILE_TYPE_CHAR)
 104                 return 0;
 105
 106         /* check if its a handle to a console output screen buffer */
 107         if (!fd) {
 108                 if (!GetConsoleMode(hcon, &mode))
 109                         return 0;
 110                 /*
 111                  * This code path is only reached if there is no console
 112                  * attached to stdout/stderr, i.e. we will not need to output
 113                  * any text to any console, therefore we might just as well
 114                  * use black as foreground color.
 115                  */
 116                 sbi.wAttributes = 0;
 117         } else if (!GetConsoleScreenBufferInfo(hcon, &sbi))
 118                 return 0;
 119
 120         if (fd >= 0 && fd <= 2)
 121                 fd_is_interactive[fd] |= FD_CONSOLE;
 122
 123         /* initialize attributes */
 124         if (!initialized) {
 125                 console = hcon;
 126                 attr = plain_attr = sbi.wAttributes;
 127                 negative = 0;
 128                 initialized = 1;
 129         }
 130
 131         return 1;
 132 }
 133
 134 #define BUFFER_SIZE 4096
 135 #define MAX_PARAMS 16
 136
 137 static void write_console(unsigned char *str, size_t len)
 138 {
 139         /* only called from console_thread, so a static buffer will do */
 140         static wchar_t wbuf[2 * BUFFER_SIZE + 1];
 141         DWORD dummy;
 142
 143         /* convert utf-8 to utf-16 */
 144         int wlen = xutftowcsn(wbuf, (char*) str, ARRAY_SIZE(wbuf), len);
 145         if (wlen < 0) {
 146                 wchar_t *err = L"[invalid]";
 147                 WriteConsoleW(console, err, wcslen(err), &dummy, NULL);
 148                 return;
 149         }
 150
 151         /* write directly to console */
 152         WriteConsoleW(console, wbuf, wlen, &dummy, NULL);
 153
 154         /* remember if non-ascii characters are printed */
 155         if (wlen != len)
 156                 non_ascii_used = 1;
 157 }
 158
 159 #define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
 160 #define BACKGROUND_ALL (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE)
 161
 162 static void set_console_attr(void)
 163 {
 164         WORD attributes = attr;
 165         if (negative) {
 166                 attributes &= ~FOREGROUND_ALL;
 167                 attributes &= ~BACKGROUND_ALL;
 168
 169                 /* This could probably use a bitmask
 170                    instead of a series of ifs */
 171                 if (attr & FOREGROUND_RED)
 172                         attributes |= BACKGROUND_RED;
 173                 if (attr & FOREGROUND_GREEN)
 174                         attributes |= BACKGROUND_GREEN;
 175                 if (attr & FOREGROUND_BLUE)
 176                         attributes |= BACKGROUND_BLUE;
 177
 178                 if (attr & BACKGROUND_RED)
 179                         attributes |= FOREGROUND_RED;
 180                 if (attr & BACKGROUND_GREEN)
 181                         attributes |= FOREGROUND_GREEN;
 182                 if (attr & BACKGROUND_BLUE)
 183                         attributes |= FOREGROUND_BLUE;
 184         }
 185         SetConsoleTextAttribute(console, attributes);
 186 }
 187
 188 static void erase_in_line(void)
 189 {
 190         CONSOLE_SCREEN_BUFFER_INFO sbi;
 191         DWORD dummy; /* Needed for Windows 7 (or Vista) regression */
 192
 193         if (!console)
 194                 return;
 195
 196         GetConsoleScreenBufferInfo(console, &sbi);
 197         FillConsoleOutputCharacterA(console, ' ',
 198                 sbi.dwSize.X - sbi.dwCursorPosition.X, sbi.dwCursorPosition,
 199                 &dummy);
 200 }
 201
 202 static void set_attr(char func, const int *params, int paramlen)
 203 {
 204         int i;
 205         switch (func) {
 206         case 'm':
 207                 for (i = 0; i < paramlen; i++) {
 208                         switch (params[i]) {
 209                         case 0: /* reset */
 210                                 attr = plain_attr;
 211                                 negative = 0;
 212                                 break;
 213                         case 1: /* bold */
 214                                 attr |= FOREGROUND_INTENSITY;
 215                                 break;
 216                         case 2:  /* faint */
 217                         case 22: /* normal */
 218                                 attr &= ~FOREGROUND_INTENSITY;
 219                                 break;
 220                         case 3:  /* italic */
 221                                 /* Unsupported */
 222                                 break;
 223                         case 4:  /* underline */
 224                         case 21: /* double underline */
 225                                 /* Wikipedia says this flag does nothing */
 226                                 /* Furthermore, mingw doesn't define this flag
 227                                 attr |= COMMON_LVB_UNDERSCORE; */
 228                                 break;
 229                         case 24: /* no underline */
 230                                 /* attr &= ~COMMON_LVB_UNDERSCORE; */
 231                                 break;
 232                         case 5:  /* slow blink */
 233                         case 6:  /* fast blink */
 234                                 /* We don't have blink, but we do have
 235                                    background intensity */
 236                                 attr |= BACKGROUND_INTENSITY;
 237                                 break;
 238                         case 25: /* no blink */
 239                                 attr &= ~BACKGROUND_INTENSITY;
 240                                 break;
 241                         case 7:  /* negative */
 242                                 negative = 1;
 243                                 break;
 244                         case 27: /* positive */
 245                                 negative = 0;
 246                                 break;
 247                         case 8:  /* conceal */
 248                         case 28: /* reveal */
 249                                 /* Unsupported */
 250                                 break;
 251                         case 30: /* Black */
 252                                 attr &= ~FOREGROUND_ALL;
 253                                 break;
 254                         case 31: /* Red */
 255                                 attr &= ~FOREGROUND_ALL;
 256                                 attr |= FOREGROUND_RED;
 257                                 break;
 258                         case 32: /* Green */
 259                                 attr &= ~FOREGROUND_ALL;
 260                                 attr |= FOREGROUND_GREEN;
 261                                 break;
 262                         case 33: /* Yellow */
 263                                 attr &= ~FOREGROUND_ALL;
 264                                 attr |= FOREGROUND_RED | FOREGROUND_GREEN;
 265                                 break;
 266                         case 34: /* Blue */
 267                                 attr &= ~FOREGROUND_ALL;
 268                                 attr |= FOREGROUND_BLUE;
 269                                 break;
 270                         case 35: /* Magenta */
 271                                 attr &= ~FOREGROUND_ALL;
 272                                 attr |= FOREGROUND_RED | FOREGROUND_BLUE;
 273                                 break;
 274                         case 36: /* Cyan */
 275                                 attr &= ~FOREGROUND_ALL;
 276                                 attr |= FOREGROUND_GREEN | FOREGROUND_BLUE;
 277                                 break;
 278                         case 37: /* White */
 279                                 attr |= FOREGROUND_RED |
 280                                         FOREGROUND_GREEN |
 281                                         FOREGROUND_BLUE;
 282                                 break;
 283                         case 38: /* Unknown */
 284                                 break;
 285                         case 39: /* reset */
 286                                 attr &= ~FOREGROUND_ALL;
 287                                 attr |= (plain_attr & FOREGROUND_ALL);
 288                                 break;
 289                         case 40: /* Black */
 290                                 attr &= ~BACKGROUND_ALL;
 291                                 break;
 292                         case 41: /* Red */
 293                                 attr &= ~BACKGROUND_ALL;
 294                                 attr |= BACKGROUND_RED;
 295                                 break;
 296                         case 42: /* Green */
 297                                 attr &= ~BACKGROUND_ALL;
 298                                 attr |= BACKGROUND_GREEN;
 299                                 break;
 300                         case 43: /* Yellow */
 301                                 attr &= ~BACKGROUND_ALL;
 302                                 attr |= BACKGROUND_RED | BACKGROUND_GREEN;
 303                                 break;
 304                         case 44: /* Blue */
 305                                 attr &= ~BACKGROUND_ALL;
 306                                 attr |= BACKGROUND_BLUE;
 307                                 break;
 308                         case 45: /* Magenta */
 309                                 attr &= ~BACKGROUND_ALL;
 310                                 attr |= BACKGROUND_RED | BACKGROUND_BLUE;
 311                                 break;
 312                         case 46: /* Cyan */
 313                                 attr &= ~BACKGROUND_ALL;
 314                                 attr |= BACKGROUND_GREEN | BACKGROUND_BLUE;
 315                                 break;
 316                         case 47: /* White */
 317                                 attr |= BACKGROUND_RED |
 318                                         BACKGROUND_GREEN |
 319                                         BACKGROUND_BLUE;
 320                                 break;
 321                         case 48: /* Unknown */
 322                                 break;
 323                         case 49: /* reset */
 324                                 attr &= ~BACKGROUND_ALL;
 325                                 attr |= (plain_attr & BACKGROUND_ALL);
 326                                 break;
 327                         default:
 328                                 /* Unsupported code */
 329                                 break;
 330                         }
 331                 }
 332                 set_console_attr();
 333                 break;
 334         case 'K':
 335                 erase_in_line();
 336                 break;
 337         default:
 338                 /* Unsupported code */
 339                 break;
 340         }
 341 }
 342
 343 enum {
 344         TEXT = 0, ESCAPE = 033, BRACKET = '['
 345 };
 346
 347 static DWORD WINAPI console_thread(LPVOID unused)
 348 {
 349         unsigned char buffer[BUFFER_SIZE];
 350         DWORD bytes;
 351         int start, end = 0, c, parampos = 0, state = TEXT;
 352         int params[MAX_PARAMS];
 353
 354         while (1) {
 355                 /* read next chunk of bytes from the pipe */
 356                 if (!ReadFile(hread, buffer + end, BUFFER_SIZE - end, &bytes,
 357                                 NULL)) {
 358                         /* exit if pipe has been closed or disconnected */
 359                         if (GetLastError() == ERROR_PIPE_NOT_CONNECTED ||
 360                                         GetLastError() == ERROR_BROKEN_PIPE)
 361                                 break;
 362                         /* ignore other errors */
 363                         continue;
 364                 }
 365
 366                 /* scan the bytes and handle ANSI control codes */
 367                 bytes += end;
 368                 start = end = 0;
 369                 while (end < bytes) {
 370                         c = buffer[end++];
 371                         switch (state) {
 372                         case TEXT:
 373                                 if (c == ESCAPE) {
 374                                         /* print text seen so far */
 375                                         if (end - 1 > start)
 376                                                 write_console(buffer + start,
 377                                                         end - 1 - start);
 378
 379                                         /* then start parsing escape sequence */
 380                                         start = end - 1;
 381                                         memset(params, 0, sizeof(params));
 382                                         parampos = 0;
 383                                         state = ESCAPE;
 384                                 }
 385                                 break;
 386
 387                         case ESCAPE:
 388                                 /* continue if "\033[", otherwise bail out */
 389                                 state = (c == BRACKET) ? BRACKET : TEXT;
 390                                 break;
 391
 392                         case BRACKET:
 393                                 /* parse [0-9;]* into array of parameters */
 394                                 if (c >= '0' && c <= '9') {
 395                                         params[parampos] *= 10;
 396                                         params[parampos] += c - '0';
 397                                 } else if (c == ';') {
 398                                         /*
 399                                          * next parameter, bail out if out of
 400                                          * bounds
 401                                          */
 402                                         parampos++;
 403                                         if (parampos >= MAX_PARAMS)
 404                                                 state = TEXT;
 405                                 } else {
 406                                         /*
 407                                          * end of escape sequence, change
 408                                          * console attributes
 409                                          */
 410                                         set_attr(c, params, parampos + 1);
 411                                         start = end;
 412                                         state = TEXT;
 413                                 }
 414                                 break;
 415                         }
 416                 }
 417
 418                 /* print remaining text unless parsing an escape sequence */
 419                 if (state == TEXT && end > start) {
 420                         /* check for incomplete UTF-8 sequences and fix end */
 421                         if (buffer[end - 1] >= 0x80) {
 422                                 if (buffer[end -1] >= 0xc0)
 423                                         end--;
 424                                 else if (end - 1 > start &&
 425                                                 buffer[end - 2] >= 0xe0)
 426                                         end -= 2;
 427                                 else if (end - 2 > start &&
 428                                                 buffer[end - 3] >= 0xf0)
 429                                         end -= 3;
 430                         }
 431
 432                         /* print remaining complete UTF-8 sequences */
 433                         if (end > start)
 434                                 write_console(buffer + start, end - start);
 435
 436                         /* move remaining bytes to the front */
 437                         if (end < bytes)
 438                                 memmove(buffer, buffer + end, bytes - end);
 439                         end = bytes - end;
 440                 } else {
 441                         /* all data has been consumed, mark buffer empty */
 442                         end = 0;
 443                 }
 444         }
 445
 446         /* check if the console font supports unicode */
 447         warn_if_raster_font();
 448
 449         CloseHandle(hread);
 450         return 0;
 451 }
 452
 453 static void winansi_exit(void)
 454 {
 455         /* flush all streams */
 456         _flushall();
 457
 458         /* signal console thread to exit */
 459         FlushFileBuffers(hwrite);
 460         DisconnectNamedPipe(hwrite);
 461
 462         /* wait for console thread to copy remaining data */
 463         WaitForSingleObject(hthread, INFINITE);
 464
 465         /* cleanup handles... */
 466         CloseHandle(hwrite);
 467         CloseHandle(hthread);
 468 }
 469
 470 static void die_lasterr(const char *fmt, ...)
 471 {
 472         va_list params;
 473         va_start(params, fmt);
 474         errno = err_win_to_posix(GetLastError());
 475         die_errno(fmt, params);
 476         va_end(params);
 477 }
 478
 479 #undef dup2
 480 int winansi_dup2(int oldfd, int newfd)
 481 {
 482         int ret = dup2(oldfd, newfd);
 483
 484         if (!ret && newfd >= 0 && newfd <= 2)
 485                 fd_is_interactive[newfd] = oldfd < 0 || oldfd > 2 ?
 486                         0 : fd_is_interactive[oldfd];
 487
 488         return ret;
 489 }
 490
 491 static HANDLE duplicate_handle(HANDLE hnd)
 492 {
 493         HANDLE hresult, hproc = GetCurrentProcess();
 494         if (!DuplicateHandle(hproc, hnd, hproc, &hresult, 0, TRUE,
 495                         DUPLICATE_SAME_ACCESS))
 496                 die_lasterr("DuplicateHandle(%li) failed",
 497                         (long) (intptr_t) hnd);
 498         return hresult;
 499 }
 500
 501 static HANDLE swap_osfhnd(int fd, HANDLE new_handle)
 502 {
 503         /*
 504          * Create a copy of the original handle associated with fd
 505          * because the original will get closed when we dup2().
 506          */
 507         HANDLE handle = (HANDLE)_get_osfhandle(fd);
 508         HANDLE duplicate = duplicate_handle(handle);
 509
 510         /* Create a temp fd associated with the already open "new_handle". */
 511         int new_fd = _open_osfhandle((intptr_t)new_handle, O_BINARY);
 512
 513         assert((fd == 1) || (fd == 2));
 514
 515         /*
 516          * Use stock dup2() to re-bind fd to the new handle.  Note that
 517          * this will implicitly close(1) and close both fd=1 and the
 518          * originally associated handle.  It will open a new fd=1 and
 519          * call DuplicateHandle() on the handle associated with new_fd.
 520          * It is because of this implicit close() that we created the
 521          * copy of the original.
 522          *
 523          * Note that we need to update the cached console handle to the
 524          * duplicated one because the dup2() call will implicitly close
 525          * the original one.
 526          *
 527          * Note that dup2() when given target := {0,1,2} will also
 528          * call SetStdHandle(), so we don't need to worry about that.
 529          */
 530         if (console == handle)
 531                 console = duplicate;
 532         dup2(new_fd, fd);
 533
 534         /* Close the temp fd.  This explicitly closes "new_handle"
 535          * (because it has been associated with it).
 536          */
 537         close(new_fd);
 538
 539         if (fd == 2)
 540                 setvbuf(stderr, NULL, _IONBF, BUFSIZ);
 541         fd_is_interactive[fd] |= FD_SWAPPED;
 542
 543         return duplicate;
 544 }
 545
 546 #ifdef DETECT_MSYS_TTY
 547
 548 #include <winternl.h>
 549
 550 #if defined(_MSC_VER)
 551
 552 typedef struct _OBJECT_NAME_INFORMATION
 553 {
 554         UNICODE_STRING Name;
 555         WCHAR NameBuffer[FLEX_ARRAY];
 556 } OBJECT_NAME_INFORMATION, *POBJECT_NAME_INFORMATION;
 557
 558 #define ObjectNameInformation 1
 559
 560 #else
 561 #include <ntstatus.h>
 562 #endif
 563
 564 static void detect_msys_tty(int fd)
 565 {
 566         ULONG result;
 567         BYTE buffer[1024];
 568         POBJECT_NAME_INFORMATION nameinfo = (POBJECT_NAME_INFORMATION) buffer;
 569         PWSTR name;
 570
 571         /* check if fd is a pipe */
 572         HANDLE h = (HANDLE) _get_osfhandle(fd);
 573         if (GetFileType(h) != FILE_TYPE_PIPE)
 574                 return;
 575
 576         /* get pipe name */
 577         if (!NT_SUCCESS(NtQueryObject(h, ObjectNameInformation,
 578                         buffer, sizeof(buffer) - 2, &result)))
 579                 return;
 580         name = nameinfo->Name.Buffer;
 581         name[nameinfo->Name.Length / sizeof(*name)] = 0;
 582
 583         /*
 584          * Check if this could be a MSYS2 pty pipe ('msys-XXXX-ptyN-XX')
 585          * or a cygwin pty pipe ('cygwin-XXXX-ptyN-XX')
 586          */
 587         if ((!wcsstr(name, L"msys-") && !wcsstr(name, L"cygwin-")) ||
 588                         !wcsstr(name, L"-pty"))
 589                 return;
 590
 591         if (fd == 2)
 592                 setvbuf(stderr, NULL, _IONBF, BUFSIZ);
 593         fd_is_interactive[fd] |= FD_MSYS;
 594 }
 595
 596 #endif
 597
 598 /*
 599  * Wrapper for isatty().  Most calls in the main git code
 600  * call isatty(1 or 2) to see if the instance is interactive
 601  * and should: be colored, show progress, paginate output.
 602  * We lie and give results for what the descriptor WAS at
 603  * startup (and ignore any pipe redirection we internally
 604  * do).
 605  */
 606 #undef isatty
 607 int winansi_isatty(int fd)
 608 {
 609         if (fd >= 0 && fd <= 2)
 610                 return fd_is_interactive[fd] != 0;
 611         return isatty(fd);
 612 }
 613
 614 void winansi_init(void)
 615 {
 616         int con1, con2;
 617         wchar_t name[32];
 618
 619         /* check if either stdout or stderr is a console output screen buffer */
 620         con1 = is_console(1);
 621         con2 = is_console(2);
 622
 623         /* Also compute console bit for fd 0 even though we don't need the result here. */
 624         is_console(0);
 625
 626         if (!con1 && !con2) {
 627 #ifdef DETECT_MSYS_TTY
 628                 /* check if stdin / stdout / stderr are MSYS2 pty pipes */
 629                 detect_msys_tty(0);
 630                 detect_msys_tty(1);
 631                 detect_msys_tty(2);
 632 #endif
 633                 return;
 634         }
 635
 636         /* create a named pipe to communicate with the console thread */
 637         if (swprintf(name, ARRAY_SIZE(name) - 1, L"\\\\.\\pipe\\winansi%lu",
 638                      GetCurrentProcessId()) < 0)
 639                 die("Could not initialize winansi pipe name");
 640         hwrite = CreateNamedPipeW(name, PIPE_ACCESS_OUTBOUND,
 641                 PIPE_TYPE_BYTE | PIPE_WAIT, 1, BUFFER_SIZE, 0, 0, NULL);
 642         if (hwrite == INVALID_HANDLE_VALUE)
 643                 die_lasterr("CreateNamedPipe failed");
 644
 645         hread = CreateFileW(name, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
 646         if (hread == INVALID_HANDLE_VALUE)
 647                 die_lasterr("CreateFile for named pipe failed");
 648
 649         /* start console spool thread on the pipe's read end */
 650         hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
 651         if (hthread == INVALID_HANDLE_VALUE)
 652                 die_lasterr("CreateThread(console_thread) failed");
 653
 654         /* schedule cleanup routine */
 655         if (atexit(winansi_exit))
 656                 die_errno("atexit(winansi_exit) failed");
 657
 658         /* redirect stdout / stderr to the pipe */
 659         if (con1)
 660                 hconsole1 = swap_osfhnd(1, duplicate_handle(hwrite));
 661         if (con2)
 662                 hconsole2 = swap_osfhnd(2, duplicate_handle(hwrite));
 663 }
 664
 665 /*
 666  * Returns the real console handle if stdout / stderr is a pipe redirecting
 667  * to the console. Allows spawn / exec to pass the console to the next process.
 668  */
 669 HANDLE winansi_get_osfhandle(int fd)
 670 {
 671         HANDLE ret;
 672
 673         if (fd == 1 && (fd_is_interactive[1] & FD_SWAPPED))
 674                 return hconsole1;
 675         if (fd == 2 && (fd_is_interactive[2] & FD_SWAPPED))
 676                 return hconsole2;
 677
 678         ret = (HANDLE)_get_osfhandle(fd);
 679
 680         /*
 681          * There are obviously circumstances under which _get_osfhandle()
 682          * returns (HANDLE)-2. This is not documented anywhere, but that is so
 683          * clearly an invalid handle value that we can just work around this
 684          * and return the correct value for invalid handles.
 685          */
 686         return ret == (HANDLE)-2 ? INVALID_HANDLE_VALUE : ret;
 687 }