Merge branch 'sk/mingw-uni-console'

* sk/mingw-uni-console:
  Win32: reliably detect console pipe handles
  Win32: fix broken pipe detection
  Win32: Thread-safe windows console output
  Win32: add Unicode conversion functions
  Win32: warn if the console font doesn't support Unicode
  Win32: detect console streams more reliably
  Win32: support Unicode console output

3 files changed, 533 insertions, 123 deletions

diff --git a/compat/mingw.c b/compat/mingw.c
index c03bafa..d242557 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -865,9 +865,9 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **env,
 	memset(&si, 0, sizeof(si));
 	si.cb = sizeof(si);
 	si.dwFlags = STARTF_USESTDHANDLES;
-	si.hStdInput = (HANDLE) _get_osfhandle(fhin);
-	si.hStdOutput = (HANDLE) _get_osfhandle(fhout);
-	si.hStdError = (HANDLE) _get_osfhandle(fherr);
+	si.hStdInput = winansi_get_osfhandle(fhin);
+	si.hStdOutput = winansi_get_osfhandle(fhout);
+	si.hStdError = winansi_get_osfhandle(fherr);
 
 	/* concatenate argv, quoting args as we go */
 	strbuf_init(&args, 0);
@@ -1848,6 +1848,91 @@ int mingw_offset_1st_component(const char *path)
 	return offset + is_dir_sep(path[offset]);
 }
 
+int xutftowcsn(wchar_t *wcs, const char *utfs, size_t wcslen, int utflen)
+{
+	int upos = 0, wpos = 0;
+	const unsigned char *utf = (const unsigned char*) utfs;
+	if (!utf || !wcs || wcslen < 1) {
+		errno = EINVAL;
+		return -1;
+	}
+	/* reserve space for \0 */
+	wcslen--;
+	if (utflen < 0)
+		utflen = INT_MAX;
+
+	while (upos < utflen) {
+		int c = utf[upos++] & 0xff;
+		if (utflen == INT_MAX && c == 0)
+			break;
+
+		if (wpos >= wcslen) {
+			wcs[wpos] = 0;
+			errno = ERANGE;
+			return -1;
+		}
+
+		if (c < 0x80) {
+			/* ASCII */
+			wcs[wpos++] = c;
+		} else if (c >= 0xc2 && c < 0xe0 && upos < utflen &&
+				(utf[upos] & 0xc0) == 0x80) {
+			/* 2-byte utf-8 */
+			c = ((c & 0x1f) << 6);
+			c |= (utf[upos++] & 0x3f);
+			wcs[wpos++] = c;
+		} else if (c >= 0xe0 && c < 0xf0 && upos + 1 < utflen &&
+				!(c == 0xe0 && utf[upos] < 0xa0) && /* over-long encoding */
+				(utf[upos] & 0xc0) == 0x80 &&
+				(utf[upos + 1] & 0xc0) == 0x80) {
+			/* 3-byte utf-8 */
+			c = ((c & 0x0f) << 12);
+			c |= ((utf[upos++] & 0x3f) << 6);
+			c |= (utf[upos++] & 0x3f);
+			wcs[wpos++] = c;
+		} else if (c >= 0xf0 && c < 0xf5 && upos + 2 < utflen &&
+				wpos + 1 < wcslen &&
+				!(c == 0xf0 && utf[upos] < 0x90) && /* over-long encoding */
+				!(c == 0xf4 && utf[upos] >= 0x90) && /* > \u10ffff */
+				(utf[upos] & 0xc0) == 0x80 &&
+				(utf[upos + 1] & 0xc0) == 0x80 &&
+				(utf[upos + 2] & 0xc0) == 0x80) {
+			/* 4-byte utf-8: convert to \ud8xx \udcxx surrogate pair */
+			c = ((c & 0x07) << 18);
+			c |= ((utf[upos++] & 0x3f) << 12);
+			c |= ((utf[upos++] & 0x3f) << 6);
+			c |= (utf[upos++] & 0x3f);
+			c -= 0x10000;
+			wcs[wpos++] = 0xd800 | (c >> 10);
+			wcs[wpos++] = 0xdc00 | (c & 0x3ff);
+		} else if (c >= 0xa0) {
+			/* invalid utf-8 byte, printable unicode char: convert 1:1 */
+			wcs[wpos++] = c;
+		} else {
+			/* invalid utf-8 byte, non-printable unicode: convert to hex */
+			static const char *hex = "0123456789abcdef";
+			wcs[wpos++] = hex[c >> 4];
+			if (wpos < wcslen)
+				wcs[wpos++] = hex[c & 0x0f];
+		}
+	}
+	wcs[wpos] = 0;
+	return wpos;
+}
+
+int xwcstoutf(char *utf, const wchar_t *wcs, size_t utflen)
+{
+	if (!wcs || !utf || utflen < 1) {
+		errno = EINVAL;
+		return -1;
+	}
+	utflen = WideCharToMultiByte(CP_UTF8, 0, wcs, -1, utf, utflen, NULL, NULL);
+	if (utflen)
+		return utflen - 1;
+	errno = ERANGE;
+	return -1;
+}
+
 void mingw_startup()
 {
 	/* copy executable name to argv[0] */
@@ -1861,4 +1946,7 @@ void mingw_startup()
 	_setmode(_fileno(stdin), _O_BINARY);
 	_setmode(_fileno(stdout), _O_BINARY);
 	_setmode(_fileno(stderr), _O_BINARY);
+
+	/* initialize Unicode console */
+	winansi_init();
 }
diff --git a/compat/mingw.h b/compat/mingw.h
index 6dc8b1a..8dac6f9 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -317,12 +317,8 @@ int mingw_raise(int sig);
  * ANSI emulation wrappers
  */
 
-int winansi_fputs(const char *str, FILE *stream);
-int winansi_printf(const char *format, ...) __attribute__((format (printf, 1, 2)));
-int winansi_fprintf(FILE *stream, const char *format, ...) __attribute__((format (printf, 2, 3)));
-#define fputs winansi_fputs
-#define printf(...) winansi_printf(__VA_ARGS__)
-#define fprintf(...) winansi_fprintf(__VA_ARGS__)
+void winansi_init(void);
+HANDLE winansi_get_osfhandle(int fd);
 
 /*
  * git specific compatibility
@@ -355,6 +351,110 @@ void mingw_open_html(const char *path);
 char **make_augmented_environ(const char *const *vars);
 void free_environ(char **env);
 
+/**
+ * Converts UTF-8 encoded string to UTF-16LE.
+ *
+ * To support repositories with legacy-encoded file names, invalid UTF-8 bytes
+ * 0xa0 - 0xff are converted to corresponding printable Unicode chars \u00a0 -
+ * \u00ff, and invalid UTF-8 bytes 0x80 - 0x9f (which would make non-printable
+ * Unicode) are converted to hex-code.
+ *
+ * Lead-bytes not followed by an appropriate number of trail-bytes, over-long
+ * encodings and 4-byte encodings > \u10ffff are detected as invalid UTF-8.
+ *
+ * Maximum space requirement for the target buffer is two wide chars per UTF-8
+ * char (((strlen(utf) * 2) + 1) [* sizeof(wchar_t)]).
+ *
+ * The maximum space is needed only if the entire input string consists of
+ * invalid UTF-8 bytes in range 0x80-0x9f, as per the following table:
+ *
+ *               |                   | UTF-8 | UTF-16 |
+ *   Code point  |  UTF-8 sequence   | bytes | words  | ratio
+ * --------------+-------------------+-------+--------+-------
+ * 000000-00007f | 0-7f              |   1   |   1    |  1
+ * 000080-0007ff | c2-df + 80-bf     |   2   |   1    |  0.5
+ * 000800-00ffff | e0-ef + 2 * 80-bf |   3   |   1    |  0.33
+ * 010000-10ffff | f0-f4 + 3 * 80-bf |   4   |  2 (a) |  0.5
+ * invalid       | 80-9f             |   1   |  2 (b) |  2
+ * invalid       | a0-ff             |   1   |   1    |  1
+ *
+ * (a) encoded as UTF-16 surrogate pair
+ * (b) encoded as two hex digits
+ *
+ * Note that, while the UTF-8 encoding scheme can be extended to 5-byte, 6-byte
+ * or even indefinite-byte sequences, the largest valid code point \u10ffff
+ * encodes as only 4 UTF-8 bytes.
+ *
+ * Parameters:
+ * wcs: wide char target buffer
+ * utf: string to convert
+ * wcslen: size of target buffer (in wchar_t's)
+ * utflen: size of string to convert, or -1 if 0-terminated
+ *
+ * Returns:
+ * length of converted string (_wcslen(wcs)), or -1 on failure
+ *
+ * Errors:
+ * EINVAL: one of the input parameters is invalid (e.g. NULL)
+ * ERANGE: the output buffer is too small
+ */
+int xutftowcsn(wchar_t *wcs, const char *utf, size_t wcslen, int utflen);
+
+/**
+ * Simplified variant of xutftowcsn, assumes input string is \0-terminated.
+ */
+static inline int xutftowcs(wchar_t *wcs, const char *utf, size_t wcslen)
+{
+	return xutftowcsn(wcs, utf, wcslen, -1);
+}
+
+/**
+ * Simplified file system specific variant of xutftowcsn, assumes output
+ * buffer size is MAX_PATH wide chars and input string is \0-terminated,
+ * fails with ENAMETOOLONG if input string is too long.
+ */
+static inline int xutftowcs_path(wchar_t *wcs, const char *utf)
+{
+	int result = xutftowcsn(wcs, utf, MAX_PATH, -1);
+	if (result < 0 && errno == ERANGE)
+		errno = ENAMETOOLONG;
+	return result;
+}
+
+/**
+ * Converts UTF-16LE encoded string to UTF-8.
+ *
+ * Maximum space requirement for the target buffer is three UTF-8 chars per
+ * wide char ((_wcslen(wcs) * 3) + 1).
+ *
+ * The maximum space is needed only if the entire input string consists of
+ * UTF-16 words in range 0x0800-0xd7ff or 0xe000-0xffff (i.e. \u0800-\uffff
+ * modulo surrogate pairs), as per the following table:
+ *
+ *               |                       | UTF-16 | UTF-8 |
+ *   Code point  |  UTF-16 sequence      | words  | bytes | ratio
+ * --------------+-----------------------+--------+-------+-------
+ * 000000-00007f | 0000-007f             |   1    |   1   |  1
+ * 000080-0007ff | 0080-07ff             |   1    |   2   |  2
+ * 000800-00ffff | 0800-d7ff / e000-ffff |   1    |   3   |  3
+ * 010000-10ffff | d800-dbff + dc00-dfff |   2    |   4   |  2
+ *
+ * Note that invalid code points > 10ffff cannot be represented in UTF-16.
+ *
+ * Parameters:
+ * utf: target buffer
+ * wcs: wide string to convert
+ * utflen: size of target buffer
+ *
+ * Returns:
+ * length of converted string, or -1 on failure
+ *
+ * Errors:
+ * EINVAL: one of the input parameters is invalid (e.g. NULL)
+ * ERANGE: the output buffer is too small
+ */
+int xwcstoutf(char *utf, const wchar_t *wcs, size_t utflen);
+
 /*
  * A critical section used in the implementation of the spawn
  * functions (mingw_spawnv[p]e()) and waitpid(). Intialised in
diff --git a/compat/winansi.c b/compat/winansi.c
index dedce21..efc5bb3 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -2,15 +2,10 @@
  * Copyright 2008 Peter Harris <git@peter.is-a-geek.org>
  */
 
+#undef NOGDI
 #include "../git-compat-util.h"
-
-/*
- Functions to be wrapped:
-*/
-#undef printf
-#undef fprintf
-#undef fputs
-/* TODO: write */
+#include <wingdi.h>
+#include <winreg.h>
 
 /*
  ANSI codes used by git: m, K
@@ -23,29 +18,114 @@ static HANDLE console;
 static WORD plain_attr;
 static WORD attr;
 static int negative;
+static int non_ascii_used = 0;
+static HANDLE hthread, hread, hwrite;
+static HANDLE hconsole1, hconsole2;
+
+#ifdef __MINGW32__
+typedef struct _CONSOLE_FONT_INFOEX {
+	ULONG cbSize;
+	DWORD nFont;
+	COORD dwFontSize;
+	UINT FontFamily;
+	UINT FontWeight;
+	WCHAR FaceName[LF_FACESIZE];
+} CONSOLE_FONT_INFOEX, *PCONSOLE_FONT_INFOEX;
+#endif
+
+typedef BOOL (WINAPI *PGETCURRENTCONSOLEFONTEX)(HANDLE, BOOL,
+		PCONSOLE_FONT_INFOEX);
+
+static void warn_if_raster_font(void)
+{
+	DWORD fontFamily = 0;
+	PGETCURRENTCONSOLEFONTEX pGetCurrentConsoleFontEx;
+
+	/* don't bother if output was ascii only */
+	if (!non_ascii_used)
+		return;
+
+	/* GetCurrentConsoleFontEx is available since Vista */
+	pGetCurrentConsoleFontEx = (PGETCURRENTCONSOLEFONTEX) GetProcAddress(
+			GetModuleHandle("kernel32.dll"),
+			"GetCurrentConsoleFontEx");
+	if (pGetCurrentConsoleFontEx) {
+		CONSOLE_FONT_INFOEX cfi;
+		cfi.cbSize = sizeof(cfi);
+		if (pGetCurrentConsoleFontEx(console, 0, &cfi))
+			fontFamily = cfi.FontFamily;
+	} else {
+		/* pre-Vista: check default console font in registry */
+		HKEY hkey;
+		if (ERROR_SUCCESS == RegOpenKeyExA(HKEY_CURRENT_USER, "Console",
+				0, KEY_READ, &hkey)) {
+			DWORD size = sizeof(fontFamily);
+			RegQueryValueExA(hkey, "FontFamily", NULL, NULL,
+					(LPVOID) &fontFamily, &size);
+			RegCloseKey(hkey);
+		}
+	}
+
+	if (!(fontFamily & TMPF_TRUETYPE)) {
+		const wchar_t *msg = L"\nWarning: Your console font probably "
+			L"doesn\'t support Unicode. If you experience strange "
+			L"characters in the output, consider switching to a "
+			L"TrueType font such as Consolas!\n";
+		DWORD dummy;
+		WriteConsoleW(console, msg, wcslen(msg), &dummy, NULL);
+	}
+}
 
-static void init(void)
+static int is_console(int fd)
 {
 	CONSOLE_SCREEN_BUFFER_INFO sbi;
+	HANDLE hcon;
 
 	static int initialized = 0;
-	if (initialized)
-		return;
 
-	console = GetStdHandle(STD_OUTPUT_HANDLE);
-	if (console == INVALID_HANDLE_VALUE)
-		console = NULL;
+	/* get OS handle of the file descriptor */
+	hcon = (HANDLE) _get_osfhandle(fd);
+	if (hcon == INVALID_HANDLE_VALUE)
+		return 0;
 
-	if (!console)
-		return;
+	/* check if its a device (i.e. console, printer, serial port) */
+	if (GetFileType(hcon) != FILE_TYPE_CHAR)
+		return 0;
 
-	GetConsoleScreenBufferInfo(console, &sbi);
-	attr = plain_attr = sbi.wAttributes;
-	negative = 0;
+	/* check if its a handle to a console output screen buffer */
+	if (!GetConsoleScreenBufferInfo(hcon, &sbi))
+		return 0;
+
+	/* initialize attributes */
+	if (!initialized) {
+		console = hcon;
+		attr = plain_attr = sbi.wAttributes;
+		negative = 0;
+		initialized = 1;
+	}
 
-	initialized = 1;
+	return 1;
 }
 
+#define BUFFER_SIZE 4096
+#define MAX_PARAMS 16
+
+static void write_console(unsigned char *str, size_t len)
+{
+	/* only called from console_thread, so a static buffer will do */
+	static wchar_t wbuf[2 * BUFFER_SIZE + 1];
+	DWORD dummy;
+
+	/* convert utf-8 to utf-16 */
+	int wlen = xutftowcsn(wbuf, (char*) str, ARRAY_SIZE(wbuf), len);
+
+	/* write directly to console */
+	WriteConsoleW(console, wbuf, wlen, &dummy, NULL);
+
+	/* remember if non-ascii characters are printed */
+	if (wlen != len)
+		non_ascii_used = 1;
+}
 
 #define FOREGROUND_ALL (FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE)
 #define BACKGROUND_ALL (BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE)
@@ -90,18 +170,13 @@ static void erase_in_line(void)
 		&dummy);
 }
 
-
-static const char *set_attr(const char *str)
+static void set_attr(char func, const int *params, int paramlen)
 {
-	const char *func;
-	size_t len = strspn(str, "0123456789;");
-	func = str + len;
-
-	switch (*func) {
+	int i;
+	switch (func) {
 	case 'm':
-		do {
-			long val = strtol(str, (char **)&str, 10);
-			switch (val) {
+		for (i = 0; i < paramlen; i++) {
+			switch (params[i]) {
 			case 0: /* reset */
 				attr = plain_attr;
 				negative = 0;
@@ -224,9 +299,7 @@ static const char *set_attr(const char *str)
 				/* Unsupported code */
 				break;
 			}
-			str++;
-		} while (*(str-1) == ';');
-
+		}
 		set_console_attr();
 		break;
 	case 'K':
@@ -236,122 +309,271 @@ static const char *set_attr(const char *str)
 		/* Unsupported code */
 		break;
 	}
-
-	return func + 1;
 }
 
-static int ansi_emulate(const char *str, FILE *stream)
+enum {
+	TEXT = 0, ESCAPE = 033, BRACKET = '['
+};
+
+static DWORD WINAPI console_thread(LPVOID unused)
 {
-	int rv = 0;
-	const char *pos = str;
-
-	while (*pos) {
-		pos = strstr(str, "\033[");
-		if (pos) {
-			size_t len = pos - str;
-
-			if (len) {
-				size_t out_len = fwrite(str, 1, len, stream);
-				rv += out_len;
-				if (out_len < len)
-					return rv;
+	unsigned char buffer[BUFFER_SIZE];
+	DWORD bytes;
+	int start, end = 0, c, parampos = 0, state = TEXT;
+	int params[MAX_PARAMS];
+
+	while (1) {
+		/* read next chunk of bytes from the pipe */
+		if (!ReadFile(hread, buffer + end, BUFFER_SIZE - end, &bytes,
+				NULL)) {
+			/* exit if pipe has been closed or disconnected */
+			if (GetLastError() == ERROR_PIPE_NOT_CONNECTED ||
+					GetLastError() == ERROR_BROKEN_PIPE)
+				break;
+			/* ignore other errors */
+			continue;
+		}
+
+		/* scan the bytes and handle ANSI control codes */
+		bytes += end;
+		start = end = 0;
+		while (end < bytes) {
+			c = buffer[end++];
+			switch (state) {
+			case TEXT:
+				if (c == ESCAPE) {
+					/* print text seen so far */
+					if (end - 1 > start)
+						write_console(buffer + start,
+							end - 1 - start);
+
+					/* then start parsing escape sequence */
+					start = end - 1;
+					memset(params, 0, sizeof(params));
+					parampos = 0;
+					state = ESCAPE;
+				}
+				break;
+
+			case ESCAPE:
+				/* continue if "\033[", otherwise bail out */
+				state = (c == BRACKET) ? BRACKET : TEXT;
+				break;
+
+			case BRACKET:
+				/* parse [0-9;]* into array of parameters */
+				if (c >= '0' && c <= '9') {
+					params[parampos] *= 10;
+					params[parampos] += c - '0';
+				} else if (c == ';') {
+					/*
+					 * next parameter, bail out if out of
+					 * bounds
+					 */
+					parampos++;
+					if (parampos >= MAX_PARAMS)
+						state = TEXT;
+				} else {
+					/*
+					 * end of escape sequence, change
+					 * console attributes
+					 */
+					set_attr(c, params, parampos + 1);
+					start = end;
+					state = TEXT;
+				}
+				break;
 			}
+		}
 
-			str = pos + 2;
-			rv += 2;
+		/* print remaining text unless parsing an escape sequence */
+		if (state == TEXT && end > start) {
+			/* check for incomplete UTF-8 sequences and fix end */
+			if (buffer[end - 1] >= 0x80) {
+				if (buffer[end -1] >= 0xc0)
+					end--;
+				else if (end - 1 > start &&
+						buffer[end - 2] >= 0xe0)
+					end -= 2;
+				else if (end - 2 > start &&
+						buffer[end - 3] >= 0xf0)
+					end -= 3;
+			}
 
-			fflush(stream);
+			/* print remaining complete UTF-8 sequences */
+			if (end > start)
+				write_console(buffer + start, end - start);
 
-			pos = set_attr(str);
-			rv += pos - str;
-			str = pos;
+			/* move remaining bytes to the front */
+			if (end < bytes)
+				memmove(buffer, buffer + end, bytes - end);
+			end = bytes - end;
 		} else {
-			rv += strlen(str);
-			fputs(str, stream);
-			return rv;
+			/* all data has been consumed, mark buffer empty */
+			end = 0;
 		}
 	}
-	return rv;
+
+	/* check if the console font supports unicode */
+	warn_if_raster_font();
+
+	CloseHandle(hread);
+	return 0;
 }
 
-int winansi_fputs(const char *str, FILE *stream)
+static void winansi_exit(void)
 {
-	int rv;
-
-	if (!isatty(fileno(stream)))
-		return fputs(str, stream);
+	/* flush all streams */
+	_flushall();
 
-	init();
+	/* signal console thread to exit */
+	FlushFileBuffers(hwrite);
+	DisconnectNamedPipe(hwrite);
 
-	if (!console)
-		return fputs(str, stream);
+	/* wait for console thread to copy remaining data */
+	WaitForSingleObject(hthread, INFINITE);
 
-	rv = ansi_emulate(str, stream);
+	/* cleanup handles... */
+	CloseHandle(hwrite);
+	CloseHandle(hthread);
+}
 
-	if (rv >= 0)
-		return 0;
-	else
-		return EOF;
+static void die_lasterr(const char *fmt, ...)
+{
+	va_list params;
+	va_start(params, fmt);
+	errno = err_win_to_posix(GetLastError());
+	die_errno(fmt, params);
+	va_end(params);
 }
 
-static int winansi_vfprintf(FILE *stream, const char *format, va_list list)
+static HANDLE duplicate_handle(HANDLE hnd)
 {
-	int len, rv;
-	char small_buf[256];
-	char *buf = small_buf;
-	va_list cp;
+	HANDLE hresult, hproc = GetCurrentProcess();
+	if (!DuplicateHandle(hproc, hnd, hproc, &hresult, 0, TRUE,
+			DUPLICATE_SAME_ACCESS))
+		die_lasterr("DuplicateHandle(%li) failed", (long) hnd);
+	return hresult;
+}
 
-	if (!isatty(fileno(stream)))
-		goto abort;
 
-	init();
+/*
+ * Make MSVCRT's internal file descriptor control structure accessible
+ * so that we can tweak OS handles and flags directly (we need MSVCRT
+ * to treat our pipe handle as if it were a console).
+ *
+ * We assume that the ioinfo structure (exposed by MSVCRT.dll via
+ * __pioinfo) starts with the OS handle and the flags. The exact size
+ * varies between MSVCRT versions, so we try different sizes until
+ * toggling the FDEV bit of _pioinfo(1)->osflags is reflected in
+ * isatty(1).
+ */
+typedef struct {
+	HANDLE osfhnd;
+	char osflags;
+} ioinfo;
 
-	if (!console)
-		goto abort;
+extern __declspec(dllimport) ioinfo *__pioinfo[];
 
-	va_copy(cp, list);
-	len = vsnprintf(small_buf, sizeof(small_buf), format, cp);
-	va_end(cp);
+static size_t sizeof_ioinfo = 0;
 
-	if (len > sizeof(small_buf) - 1) {
-		buf = malloc(len + 1);
-		if (!buf)
-			goto abort;
+#define IOINFO_L2E 5
+#define IOINFO_ARRAY_ELTS (1 << IOINFO_L2E)
 
-		len = vsnprintf(buf, len + 1, format, list);
-	}
+#define FDEV  0x40
 
-	rv = ansi_emulate(buf, stream);
+static inline ioinfo* _pioinfo(int fd)
+{
+	return (ioinfo*)((char*)__pioinfo[fd >> IOINFO_L2E] +
+			(fd & (IOINFO_ARRAY_ELTS - 1)) * sizeof_ioinfo);
+}
 
-	if (buf != small_buf)
-		free(buf);
-	return rv;
+static int init_sizeof_ioinfo()
+{
+	int istty, wastty;
+	/* don't init twice */
+	if (sizeof_ioinfo)
+		return sizeof_ioinfo >= 256;
+
+	sizeof_ioinfo = sizeof(ioinfo);
+	wastty = isatty(1);
+	while (sizeof_ioinfo < 256) {
+		/* toggle FDEV flag, check isatty, then toggle back */
+		_pioinfo(1)->osflags ^= FDEV;
+		istty = isatty(1);
+		_pioinfo(1)->osflags ^= FDEV;
+		/* return if we found the correct size */
+		if (istty != wastty)
+			return 0;
+		sizeof_ioinfo += sizeof(void*);
+	}
+	error("Tweaking file descriptors doesn't work with this MSVCRT.dll");
+	return 1;
+}
 
-abort:
-	rv = vfprintf(stream, format, list);
-	return rv;
+static HANDLE swap_osfhnd(int fd, HANDLE new_handle)
+{
+	ioinfo *pioinfo;
+	HANDLE old_handle;
+
+	/* init ioinfo size if we haven't done so */
+	if (init_sizeof_ioinfo())
+		return INVALID_HANDLE_VALUE;
+
+	/* get ioinfo pointer and change the handles */
+	pioinfo = _pioinfo(fd);
+	old_handle = pioinfo->osfhnd;
+	pioinfo->osfhnd = new_handle;
+	return old_handle;
 }
 
-int winansi_fprintf(FILE *stream, const char *format, ...)
+void winansi_init(void)
 {
-	va_list list;
-	int rv;
+	int con1, con2;
+	char name[32];
 
-	va_start(list, format);
-	rv = winansi_vfprintf(stream, format, list);
-	va_end(list);
+	/* check if either stdout or stderr is a console output screen buffer */
+	con1 = is_console(1);
+	con2 = is_console(2);
+	if (!con1 && !con2)
+		return;
 
-	return rv;
+	/* create a named pipe to communicate with the console thread */
+	sprintf(name, "\\\\.\\pipe\\winansi%lu", GetCurrentProcessId());
+	hwrite = CreateNamedPipe(name, PIPE_ACCESS_OUTBOUND,
+		PIPE_TYPE_BYTE | PIPE_WAIT, 1, BUFFER_SIZE, 0, 0, NULL);
+	if (hwrite == INVALID_HANDLE_VALUE)
+		die_lasterr("CreateNamedPipe failed");
+
+	hread = CreateFile(name, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
+	if (hread == INVALID_HANDLE_VALUE)
+		die_lasterr("CreateFile for named pipe failed");
+
+	/* start console spool thread on the pipe's read end */
+	hthread = CreateThread(NULL, 0, console_thread, NULL, 0, NULL);
+	if (hthread == INVALID_HANDLE_VALUE)
+		die_lasterr("CreateThread(console_thread) failed");
+
+	/* schedule cleanup routine */
+	if (atexit(winansi_exit))
+		die_errno("atexit(winansi_exit) failed");
+
+	/* redirect stdout / stderr to the pipe */
+	if (con1)
+		hconsole1 = swap_osfhnd(1, duplicate_handle(hwrite));
+	if (con2)
+		hconsole2 = swap_osfhnd(2, duplicate_handle(hwrite));
 }
 
-int winansi_printf(const char *format, ...)
+/*
+ * Returns the real console handle if stdout / stderr is a pipe redirecting
+ * to the console. Allows spawn / exec to pass the console to the next process.
+ */
+HANDLE winansi_get_osfhandle(int fd)
 {
-	va_list list;
-	int rv;
-
-	va_start(list, format);
-	rv = winansi_vfprintf(stdout, format, list);
-	va_end(list);
-
-	return rv;
+	HANDLE hnd = (HANDLE) _get_osfhandle(fd);
+	if ((fd == 1 || fd == 2) && isatty(fd)
+	    && GetFileType(hnd) == FILE_TYPE_PIPE)
+		return (fd == 1) ? hconsole1 : hconsole2;
+	return hnd;
 }