compat/winansi.c

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