utf8.c - jrn/git - Git at Google

 #include "git-compat-util.h"
 #include "utf8.h"

 /* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */

 typedef unsigned int ucs_char_t;  /* assuming 32bit int */

 struct interval {
   int first;
   int last;
 };

 /* auxiliary function for binary search in interval table */
 static int bisearch(ucs_char_t ucs, const struct interval *table, int max) {
 	int min = 0;
 	int mid;

 	if (ucs < table[0].first || ucs > table[max].last)
 		return 0;
 	while (max >= min) {
 		mid = (min + max) / 2;
 		if (ucs > table[mid].last)
 			min = mid + 1;
 		else if (ucs < table[mid].first)
 			max = mid - 1;
 		else
 			return 1;
 	}

 	return 0;
 }

 /* The following two functions define the column width of an ISO 10646
  * character as follows:
  *
  *    - The null character (U+0000) has a column width of 0.
  *
  *    - Other C0/C1 control characters and DEL will lead to a return
  *      value of -1.
  *
  *    - Non-spacing and enclosing combining characters (general
  *      category code Mn or Me in the Unicode database) have a
  *      column width of 0.
  *
  *    - SOFT HYPHEN (U+00AD) has a column width of 1.
  *
  *    - Other format characters (general category code Cf in the Unicode
  *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
  *
  *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
  *      have a column width of 0.
  *
  *    - Spacing characters in the East Asian Wide (W) or East Asian
  *      Full-width (F) category as defined in Unicode Technical
  *      Report #11 have a column width of 2.
  *
  *    - All remaining characters (including all printable
  *      ISO 8859-1 and WGL4 characters, Unicode control characters,
  *      etc.) have a column width of 1.
  *
  * This implementation assumes that ucs_char_t characters are encoded
  * in ISO 10646.
  */

 static int git_wcwidth(ucs_char_t ch)
 {
 	/*
 	 * Sorted list of non-overlapping intervals of non-spacing characters,
 	 * generated by
 	 *   "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
 	 */
 	static const struct interval combining[] = {
 		{ 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
 		{ 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
 		{ 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
 		{ 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
 		{ 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
 		{ 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
 		{ 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
 		{ 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
 		{ 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
 		{ 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
 		{ 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
 		{ 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
 		{ 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
 		{ 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
 		{ 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
 		{ 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
 		{ 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
 		{ 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
 		{ 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
 		{ 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
 		{ 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
 		{ 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
 		{ 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
 		{ 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
 		{ 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
 		{ 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
 		{ 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
 		{ 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
 		{ 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
 		{ 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
 		{ 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
 		{ 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
 		{ 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
 		{ 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
 		{ 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
 		{ 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
 		{ 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
 		{ 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
 		{ 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
 		{ 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
 		{ 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
 		{ 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
 	};

 	/* test for 8-bit control characters */
 	if (ch == 0)
 		return 0;
 	if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
 		return -1;

 	/* binary search in table of non-spacing characters */
 	if (bisearch(ch, combining, sizeof(combining)
 				/ sizeof(struct interval) - 1))
 		return 0;

 	/*
 	 * If we arrive here, ch is neither a combining nor a C0/C1
 	 * control character.
 	 */

 	return 1 +
 		(ch >= 0x1100 &&
                     /* Hangul Jamo init. consonants */
 		 (ch <= 0x115f ||
 		  ch == 0x2329 || ch == 0x232a ||
                   /* CJK ... Yi */
 		  (ch >= 0x2e80 && ch <= 0xa4cf &&
 		   ch != 0x303f) ||
 		  /* Hangul Syllables */
 		  (ch >= 0xac00 && ch <= 0xd7a3) ||
 		  /* CJK Compatibility Ideographs */
 		  (ch >= 0xf900 && ch <= 0xfaff) ||
 		  /* CJK Compatibility Forms */
 		  (ch >= 0xfe30 && ch <= 0xfe6f) ||
 		  /* Fullwidth Forms */
 		  (ch >= 0xff00 && ch <= 0xff60) ||
 		  (ch >= 0xffe0 && ch <= 0xffe6) ||
 		  (ch >= 0x20000 && ch <= 0x2fffd) ||
 		  (ch >= 0x30000 && ch <= 0x3fffd)));
 }

 /*
  * This function returns the number of columns occupied by the character
  * pointed to by the variable start. The pointer is updated to point at
  * the next character. If it was not valid UTF-8, the pointer is set to NULL.
  */
 int utf8_width(const char **start)
 {
 	unsigned char *s = (unsigned char *)*start;
 	ucs_char_t ch;

 	if (*s < 0x80) {
 		/* 0xxxxxxx */
 		ch = *s;
 		*start += 1;
 	} else if ((s[0] & 0xe0) == 0xc0) {
 		/* 110XXXXx 10xxxxxx */
 		if ((s[1] & 0xc0) != 0x80 ||
 				/* overlong? */
 				(s[0] & 0xfe) == 0xc0)
 			goto invalid;
 		ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
 		*start += 2;
 	} else if ((s[0] & 0xf0) == 0xe0) {
 		/* 1110XXXX 10Xxxxxx 10xxxxxx */
 		if ((s[1] & 0xc0) != 0x80 ||
 				(s[2] & 0xc0) != 0x80 ||
 				/* overlong? */
 				(s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
 				/* surrogate? */
 				(s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
 				/* U+FFFE or U+FFFF? */
 				(s[0] == 0xef && s[1] == 0xbf &&
 				 (s[2] & 0xfe) == 0xbe))
 			goto invalid;
 		ch = ((s[0] & 0x0f) << 12) |
 			((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
 		*start += 3;
 	} else if ((s[0] & 0xf8) == 0xf0) {
 		/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
 		if ((s[1] & 0xc0) != 0x80 ||
 				(s[2] & 0xc0) != 0x80 ||
 				(s[3] & 0xc0) != 0x80 ||
 				/* overlong? */
 				(s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
 				/* > U+10FFFF? */
 				(s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
 			goto invalid;
 		ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
 			((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
 		*start += 4;
 	} else {
 invalid:
 		*start = NULL;
 		return 0;
 	}

 	return git_wcwidth(ch);
 }

 int is_utf8(const char *text)
 {
 	while (*text) {
 		if (*text == '\n' || *text == '\t' || *text == '\r') {
 			text++;
 			continue;
 		}
 		utf8_width(&text);
 		if (!text)
 			return 0;
 	}
 	return 1;
 }

 static void print_spaces(int count)
 {
 	static const char s[] = "                    ";
 	while (count >= sizeof(s)) {
 		fwrite(s, sizeof(s) - 1, 1, stdout);
 		count -= sizeof(s) - 1;
 	}
 	fwrite(s, count, 1, stdout);
 }

 /*
  * Wrap the text, if necessary. The variable indent is the indent for the
  * first line, indent2 is the indent for all other lines.
  * If indent is negative, assume that already -indent columns have been
  * consumed (and no extra indent is necessary for the first line).
  */
 int print_wrapped_text(const char *text, int indent, int indent2, int width)
 {
 	int w = indent, assume_utf8 = is_utf8(text);
 	const char *bol = text, *space = NULL;

 	if (indent < 0) {
 		w = -indent;
 		space = text;
 	}

 	for (;;) {
 		char c = *text;
 		if (!c || isspace(c)) {
 			if (w < width || !space) {
 				const char *start = bol;
 				if (space)
 					start = space;
 				else
 					print_spaces(indent);
 				fwrite(start, text - start, 1, stdout);
 				if (!c)
 					return w;
 				else if (c == '\t')
 					w |= 0x07;
 				space = text;
 				w++;
 				text++;
 			}
 			else {
 				putchar('\n');
 				text = bol = space + isspace(*space);
 				space = NULL;
 				w = indent = indent2;
 			}
 			continue;
 		}
 		if (assume_utf8)
 			w += utf8_width(&text);
 		else {
 			w++;
 			text++;
 		}
 	}
 	return w;
 }

 int is_encoding_utf8(const char *name)
 {
 	if (!name)
 		return 1;
 	if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
 		return 1;
 	return 0;
 }

 /*
  * Given a buffer and its encoding, return it re-encoded
  * with iconv.  If the conversion fails, returns NULL.
  */
 #ifndef NO_ICONV
 #ifdef OLD_ICONV
 	typedef const char * iconv_ibp;
 #else
 	typedef char * iconv_ibp;
 #endif
 char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
 {
 	iconv_t conv;
 	size_t insz, outsz, outalloc;
 	char *out, *outpos;
 	iconv_ibp cp;

 	if (!in_encoding)
 		return NULL;
 	conv = iconv_open(out_encoding, in_encoding);
 	if (conv == (iconv_t) -1)
 		return NULL;
 	insz = strlen(in);
 	outsz = insz;
 	outalloc = outsz + 1; /* for terminating NUL */
 	out = xmalloc(outalloc);
 	outpos = out;
 	cp = (iconv_ibp)in;

 	while (1) {
 		size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);

 		if (cnt == -1) {
 			size_t sofar;
 			if (errno != E2BIG) {
 				free(out);
 				iconv_close(conv);
 				return NULL;
 			}
 			/* insz has remaining number of bytes.
 			 * since we started outsz the same as insz,
 			 * it is likely that insz is not enough for
 			 * converting the rest.
 			 */
 			sofar = outpos - out;
 			outalloc = sofar + insz * 2 + 32;
 			out = xrealloc(out, outalloc);
 			outpos = out + sofar;
 			outsz = outalloc - sofar - 1;
 		}
 		else {
 			*outpos = '\0';
 			break;
 		}
 	}
 	iconv_close(conv);
 	return out;
 }
 #endif
	#include "git-compat-util.h"
	#include "utf8.h"

	/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */

	typedef unsigned int ucs_char_t; /* assuming 32bit int */

	struct interval {
	int first;
	int last;
	};

	/* auxiliary function for binary search in interval table */
	static int bisearch(ucs_char_t ucs, const struct interval *table, int max) {
	int min = 0;
	int mid;

	if (ucs < table[0].first \|\| ucs > table[max].last)
	return 0;
	while (max >= min) {
	mid = (min + max) / 2;
	if (ucs > table[mid].last)
	min = mid + 1;
	else if (ucs < table[mid].first)
	max = mid - 1;
	else
	return 1;
	}

	return 0;
	}

	/* The following two functions define the column width of an ISO 10646
	* character as follows:
	*
	* - The null character (U+0000) has a column width of 0.
	*
	* - Other C0/C1 control characters and DEL will lead to a return
	* value of -1.
	*
	* - Non-spacing and enclosing combining characters (general
	* category code Mn or Me in the Unicode database) have a
	* column width of 0.
	*
	* - SOFT HYPHEN (U+00AD) has a column width of 1.
	*
	* - Other format characters (general category code Cf in the Unicode
	* database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
	*
	* - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
	* have a column width of 0.
	*
	* - Spacing characters in the East Asian Wide (W) or East Asian
	* Full-width (F) category as defined in Unicode Technical
	* Report #11 have a column width of 2.
	*
	* - All remaining characters (including all printable
	* ISO 8859-1 and WGL4 characters, Unicode control characters,
	* etc.) have a column width of 1.
	*
	* This implementation assumes that ucs_char_t characters are encoded
	* in ISO 10646.
	*/

	static int git_wcwidth(ucs_char_t ch)
	{
	/*
	* Sorted list of non-overlapping intervals of non-spacing characters,
	* generated by
	* "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
	*/
	static const struct interval combining[] = {
	{ 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
	{ 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
	{ 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
	{ 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
	{ 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
	{ 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
	{ 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
	{ 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
	{ 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
	{ 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
	{ 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
	{ 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
	{ 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
	{ 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
	{ 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
	{ 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
	{ 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
	{ 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
	{ 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
	{ 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
	{ 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
	{ 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
	{ 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
	{ 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
	{ 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
	{ 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
	{ 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
	{ 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
	{ 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
	{ 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
	{ 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
	{ 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
	{ 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
	{ 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
	{ 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
	{ 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
	{ 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
	{ 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
	{ 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
	{ 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
	{ 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
	{ 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
	};

	/* test for 8-bit control characters */
	if (ch == 0)
	return 0;
	if (ch < 32 \|\| (ch >= 0x7f && ch < 0xa0))
	return -1;

	/* binary search in table of non-spacing characters */
	if (bisearch(ch, combining, sizeof(combining)
	/ sizeof(struct interval) - 1))
	return 0;

	/*
	* If we arrive here, ch is neither a combining nor a C0/C1
	* control character.
	*/

	return 1 +
	(ch >= 0x1100 &&
	/* Hangul Jamo init. consonants */
	(ch <= 0x115f \|\|
	ch == 0x2329 \|\| ch == 0x232a \|\|
	/* CJK ... Yi */
	(ch >= 0x2e80 && ch <= 0xa4cf &&
	ch != 0x303f) \|\|
	/* Hangul Syllables */
	(ch >= 0xac00 && ch <= 0xd7a3) \|\|
	/* CJK Compatibility Ideographs */
	(ch >= 0xf900 && ch <= 0xfaff) \|\|
	/* CJK Compatibility Forms */
	(ch >= 0xfe30 && ch <= 0xfe6f) \|\|
	/* Fullwidth Forms */
	(ch >= 0xff00 && ch <= 0xff60) \|\|
	(ch >= 0xffe0 && ch <= 0xffe6) \|\|
	(ch >= 0x20000 && ch <= 0x2fffd) \|\|
	(ch >= 0x30000 && ch <= 0x3fffd)));
	}

	/*
	* This function returns the number of columns occupied by the character
	* pointed to by the variable start. The pointer is updated to point at
	* the next character. If it was not valid UTF-8, the pointer is set to NULL.
	*/
	int utf8_width(const char **start)
	{
	unsigned char s = (unsigned char )*start;
	ucs_char_t ch;

	if (*s < 0x80) {
	/* 0xxxxxxx */
	ch = *s;
	*start += 1;
	} else if ((s[0] & 0xe0) == 0xc0) {
	/* 110XXXXx 10xxxxxx */
	if ((s[1] & 0xc0) != 0x80 \|\|
	/* overlong? */
	(s[0] & 0xfe) == 0xc0)
	goto invalid;
	ch = ((s[0] & 0x1f) << 6) \| (s[1] & 0x3f);
	*start += 2;
	} else if ((s[0] & 0xf0) == 0xe0) {
	/* 1110XXXX 10Xxxxxx 10xxxxxx */
	if ((s[1] & 0xc0) != 0x80 \|\|
	(s[2] & 0xc0) != 0x80 \|\|
	/* overlong? */
	(s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) \|\|
	/* surrogate? */
	(s[0] == 0xed && (s[1] & 0xe0) == 0xa0) \|\|
	/* U+FFFE or U+FFFF? */
	(s[0] == 0xef && s[1] == 0xbf &&
	(s[2] & 0xfe) == 0xbe))
	goto invalid;
	ch = ((s[0] & 0x0f) << 12) \|
	((s[1] & 0x3f) << 6) \| (s[2] & 0x3f);
	*start += 3;
	} else if ((s[0] & 0xf8) == 0xf0) {
	/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
	if ((s[1] & 0xc0) != 0x80 \|\|
	(s[2] & 0xc0) != 0x80 \|\|
	(s[3] & 0xc0) != 0x80 \|\|
	/* overlong? */
	(s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) \|\|
	/* > U+10FFFF? */
	(s[0] == 0xf4 && s[1] > 0x8f) \|\| s[0] > 0xf4)
	goto invalid;
	ch = ((s[0] & 0x07) << 18) \| ((s[1] & 0x3f) << 12) \|
	((s[2] & 0x3f) << 6) \| (s[3] & 0x3f);
	*start += 4;
	} else {
	invalid:
	*start = NULL;
	return 0;
	}

	return git_wcwidth(ch);
	}

	int is_utf8(const char *text)
	{
	while (*text) {
	if (text == '\n' \|\| text == '\t' \|\| *text == '\r') {
	text++;
	continue;
	}
	utf8_width(&text);
	if (!text)
	return 0;
	}
	return 1;
	}

	static void print_spaces(int count)
	{
	static const char s[] = " ";
	while (count >= sizeof(s)) {
	fwrite(s, sizeof(s) - 1, 1, stdout);
	count -= sizeof(s) - 1;
	}
	fwrite(s, count, 1, stdout);
	}

	/*
	* Wrap the text, if necessary. The variable indent is the indent for the
	* first line, indent2 is the indent for all other lines.
	* If indent is negative, assume that already -indent columns have been
	* consumed (and no extra indent is necessary for the first line).
	*/
	int print_wrapped_text(const char *text, int indent, int indent2, int width)
	{
	int w = indent, assume_utf8 = is_utf8(text);
	const char bol = text, space = NULL;

	if (indent < 0) {
	w = -indent;
	space = text;
	}

	for (;;) {
	char c = *text;
	if (!c \|\| isspace(c)) {
	if (w < width \|\| !space) {
	const char *start = bol;
	if (space)
	start = space;
	else
	print_spaces(indent);
	fwrite(start, text - start, 1, stdout);
	if (!c)
	return w;
	else if (c == '\t')
	w \|= 0x07;
	space = text;
	w++;
	text++;
	}
	else {
	putchar('\n');
	text = bol = space + isspace(*space);
	space = NULL;
	w = indent = indent2;
	}
	continue;
	}
	if (assume_utf8)
	w += utf8_width(&text);
	else {
	w++;
	text++;
	}
	}
	return w;
	}

	int is_encoding_utf8(const char *name)
	{
	if (!name)
	return 1;
	if (!strcasecmp(name, "utf-8") \|\| !strcasecmp(name, "utf8"))
	return 1;
	return 0;
	}

	/*
	* Given a buffer and its encoding, return it re-encoded
	* with iconv. If the conversion fails, returns NULL.
	*/
	#ifndef NO_ICONV
	#ifdef OLD_ICONV
	typedef const char * iconv_ibp;
	#else
	typedef char * iconv_ibp;
	#endif
	char reencode_string(const char in, const char out_encoding, const char in_encoding)
	{
	iconv_t conv;
	size_t insz, outsz, outalloc;
	char out, outpos;
	iconv_ibp cp;

	if (!in_encoding)
	return NULL;
	conv = iconv_open(out_encoding, in_encoding);
	if (conv == (iconv_t) -1)
	return NULL;
	insz = strlen(in);
	outsz = insz;
	outalloc = outsz + 1; /* for terminating NUL */
	out = xmalloc(outalloc);
	outpos = out;
	cp = (iconv_ibp)in;

	while (1) {
	size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);

	if (cnt == -1) {
	size_t sofar;
	if (errno != E2BIG) {
	free(out);
	iconv_close(conv);
	return NULL;
	}
	/* insz has remaining number of bytes.
	* since we started outsz the same as insz,
	* it is likely that insz is not enough for
	* converting the rest.
	*/
	sofar = outpos - out;
	outalloc = sofar + insz * 2 + 32;
	out = xrealloc(out, outalloc);
	outpos = out + sofar;
	outsz = outalloc - sofar - 1;
	}
	else {
	*outpos = '\0';
	break;
	}
	}
	iconv_close(conv);
	return out;
	}
	#endif