Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 824 insertions, 0 deletions

diff --git a/utf8.c b/utf8.c
new file mode 100644
index 0000000..6a0dd25
--- /dev/null
+++ b/utf8.c
@@ -0,0 +1,824 @@
+#include "git-compat-util.h"
+#include "strbuf.h"
+#include "utf8.h"
+
+/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
+
+static const char utf16_be_bom[] = {'\xFE', '\xFF'};
+static const char utf16_le_bom[] = {'\xFF', '\xFE'};
+static const char utf32_be_bom[] = {'\0', '\0', '\xFE', '\xFF'};
+static const char utf32_le_bom[] = {'\xFF', '\xFE', '\0', '\0'};
+
+struct interval {
+	ucs_char_t first;
+	ucs_char_t last;
+};
+
+size_t display_mode_esc_sequence_len(const char *s)
+{
+	const char *p = s;
+	if (*p++ != '\033')
+		return 0;
+	if (*p++ != '[')
+		return 0;
+	while (isdigit(*p) || *p == ';')
+		p++;
+	if (*p++ != 'm')
+		return 0;
+	return p - s;
+}
+
+/* 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 - min) / 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,
+	 */
+#include "unicode-width.h"
+
+	/* 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, zero_width, ARRAY_SIZE(zero_width) - 1))
+		return 0;
+
+	/* binary search in table of double width characters */
+	if (bisearch(ch, double_width, ARRAY_SIZE(double_width) - 1))
+		return 2;
+
+	return 1;
+}
+
+/*
+ * Pick one ucs character starting from the location *start points at,
+ * and return it, while updating the *start pointer to point at the
+ * end of that character.  When remainder_p is not NULL, the location
+ * holds the number of bytes remaining in the string that we are allowed
+ * to pick from.  Otherwise we are allowed to pick up to the NUL that
+ * would eventually appear in the string.  *remainder_p is also reduced
+ * by the number of bytes we have consumed.
+ *
+ * If the string was not a valid UTF-8, *start pointer is set to NULL
+ * and the return value is undefined.
+ */
+static ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
+{
+	unsigned char *s = (unsigned char *)*start;
+	ucs_char_t ch;
+	size_t remainder, incr;
+
+	/*
+	 * A caller that assumes NUL terminated text can choose
+	 * not to bother with the remainder length.  We will
+	 * stop at the first NUL.
+	 */
+	remainder = (remainder_p ? *remainder_p : 999);
+
+	if (remainder < 1) {
+		goto invalid;
+	} else if (*s < 0x80) {
+		/* 0xxxxxxx */
+		ch = *s;
+		incr = 1;
+	} else if ((s[0] & 0xe0) == 0xc0) {
+		/* 110XXXXx 10xxxxxx */
+		if (remainder < 2 ||
+		    (s[1] & 0xc0) != 0x80 ||
+		    (s[0] & 0xfe) == 0xc0)
+			goto invalid;
+		ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
+		incr = 2;
+	} else if ((s[0] & 0xf0) == 0xe0) {
+		/* 1110XXXX 10Xxxxxx 10xxxxxx */
+		if (remainder < 3 ||
+		    (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);
+		incr = 3;
+	} else if ((s[0] & 0xf8) == 0xf0) {
+		/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
+		if (remainder < 4 ||
+		    (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);
+		incr = 4;
+	} else {
+invalid:
+		*start = NULL;
+		return 0;
+	}
+
+	*start += incr;
+	if (remainder_p)
+		*remainder_p = remainder - incr;
+	return ch;
+}
+
+/*
+ * 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. When remainder_p is not NULL, it points at the
+ * location that stores the number of remaining bytes we can use to pick
+ * a character (see pick_one_utf8_char() above).
+ */
+int utf8_width(const char **start, size_t *remainder_p)
+{
+	ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
+	if (!*start)
+		return 0;
+	return git_wcwidth(ch);
+}
+
+/*
+ * Returns the total number of columns required by a null-terminated
+ * string, assuming that the string is utf8.  Returns strlen() instead
+ * if the string does not look like a valid utf8 string.
+ */
+int utf8_strnwidth(const char *string, size_t len, int skip_ansi)
+{
+	const char *orig = string;
+	size_t width = 0;
+
+	while (string && string < orig + len) {
+		int glyph_width;
+		size_t skip;
+
+		while (skip_ansi &&
+		       (skip = display_mode_esc_sequence_len(string)) != 0)
+			string += skip;
+
+		glyph_width = utf8_width(&string, NULL);
+		if (glyph_width > 0)
+			width += glyph_width;
+	}
+
+	/*
+	 * TODO: fix the interface of this function and `utf8_strwidth()` to
+	 * return `size_t` instead of `int`.
+	 */
+	return cast_size_t_to_int(string ? width : len);
+}
+
+int utf8_strwidth(const char *string)
+{
+	return utf8_strnwidth(string, strlen(string), 0);
+}
+
+int is_utf8(const char *text)
+{
+	while (*text) {
+		if (*text == '\n' || *text == '\t' || *text == '\r') {
+			text++;
+			continue;
+		}
+		utf8_width(&text, NULL);
+		if (!text)
+			return 0;
+	}
+	return 1;
+}
+
+static void strbuf_add_indented_text(struct strbuf *buf, const char *text,
+				     int indent, int indent2)
+{
+	if (indent < 0)
+		indent = 0;
+	while (*text) {
+		const char *eol = strchrnul(text, '\n');
+		if (*eol == '\n')
+			eol++;
+		strbuf_addchars(buf, ' ', indent);
+		strbuf_add(buf, text, eol - text);
+		text = eol;
+		indent = indent2;
+	}
+}
+
+/*
+ * 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).
+ */
+void strbuf_add_wrapped_text(struct strbuf *buf,
+		const char *text, int indent1, int indent2, int width)
+{
+	int indent, w, assume_utf8 = 1;
+	const char *bol, *space, *start = text;
+	size_t orig_len = buf->len;
+
+	if (width <= 0) {
+		strbuf_add_indented_text(buf, text, indent1, indent2);
+		return;
+	}
+
+retry:
+	bol = text;
+	w = indent = indent1;
+	space = NULL;
+	if (indent < 0) {
+		w = -indent;
+		space = text;
+	}
+
+	for (;;) {
+		char c;
+		size_t skip;
+
+		while ((skip = display_mode_esc_sequence_len(text)))
+			text += skip;
+
+		c = *text;
+		if (!c || isspace(c)) {
+			if (w <= width || !space) {
+				const char *start = bol;
+				if (!c && text == start)
+					return;
+				if (space)
+					start = space;
+				else
+					strbuf_addchars(buf, ' ', indent);
+				strbuf_add(buf, start, text - start);
+				if (!c)
+					return;
+				space = text;
+				if (c == '\t')
+					w |= 0x07;
+				else if (c == '\n') {
+					space++;
+					if (*space == '\n') {
+						strbuf_addch(buf, '\n');
+						goto new_line;
+					}
+					else if (!isalnum(*space))
+						goto new_line;
+					else
+						strbuf_addch(buf, ' ');
+				}
+				w++;
+				text++;
+			}
+			else {
+new_line:
+				strbuf_addch(buf, '\n');
+				text = bol = space + isspace(*space);
+				space = NULL;
+				w = indent = indent2;
+			}
+			continue;
+		}
+		if (assume_utf8) {
+			w += utf8_width(&text, NULL);
+			if (!text) {
+				assume_utf8 = 0;
+				text = start;
+				strbuf_setlen(buf, orig_len);
+				goto retry;
+			}
+		} else {
+			w++;
+			text++;
+		}
+	}
+}
+
+void strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
+			     int indent, int indent2, int width)
+{
+	char *tmp = xstrndup(data, len);
+	strbuf_add_wrapped_text(buf, tmp, indent, indent2, width);
+	free(tmp);
+}
+
+void strbuf_utf8_replace(struct strbuf *sb_src, int pos, int width,
+			 const char *subst)
+{
+	const char *src = sb_src->buf, *end = sb_src->buf + sb_src->len;
+	struct strbuf dst;
+	int w = 0;
+
+	strbuf_init(&dst, sb_src->len);
+
+	while (src < end) {
+		const char *old;
+		int glyph_width;
+		size_t n;
+
+		while ((n = display_mode_esc_sequence_len(src))) {
+			strbuf_add(&dst, src, n);
+			src += n;
+		}
+
+		if (src >= end)
+			break;
+
+		old = src;
+		glyph_width = utf8_width((const char**)&src, NULL);
+		if (!src) /* broken utf-8, do nothing */
+			goto out;
+
+		/*
+		 * In case we see a control character we copy it into the
+		 * buffer, but don't add it to the width.
+		 */
+		if (glyph_width < 0)
+			glyph_width = 0;
+
+		if (glyph_width && w >= pos && w < pos + width) {
+			if (subst) {
+				strbuf_addstr(&dst, subst);
+				subst = NULL;
+			}
+		} else {
+			strbuf_add(&dst, old, src - old);
+		}
+
+		w += glyph_width;
+	}
+
+	strbuf_swap(sb_src, &dst);
+out:
+	strbuf_release(&dst);
+}
+
+/*
+ * Returns true (1) if the src encoding name matches the dst encoding
+ * name directly or one of its alternative names. E.g. UTF-16BE is the
+ * same as UTF16BE.
+ */
+static int same_utf_encoding(const char *src, const char *dst)
+{
+	if (skip_iprefix(src, "utf", &src) && skip_iprefix(dst, "utf", &dst)) {
+		skip_prefix(src, "-", &src);
+		skip_prefix(dst, "-", &dst);
+		return !strcasecmp(src, dst);
+	}
+	return 0;
+}
+
+int is_encoding_utf8(const char *name)
+{
+	if (!name)
+		return 1;
+	if (same_utf_encoding("utf-8", name))
+		return 1;
+	return 0;
+}
+
+int same_encoding(const char *src, const char *dst)
+{
+	static const char utf8[] = "UTF-8";
+
+	if (!src)
+		src = utf8;
+	if (!dst)
+		dst = utf8;
+	if (same_utf_encoding(src, dst))
+		return 1;
+	return !strcasecmp(src, dst);
+}
+
+/*
+ * Wrapper for fprintf and returns the total number of columns required
+ * for the printed string, assuming that the string is utf8.
+ */
+int utf8_fprintf(FILE *stream, const char *format, ...)
+{
+	struct strbuf buf = STRBUF_INIT;
+	va_list arg;
+	int columns;
+
+	va_start(arg, format);
+	strbuf_vaddf(&buf, format, arg);
+	va_end(arg);
+
+	columns = fputs(buf.buf, stream);
+	if (0 <= columns) /* keep the error from the I/O */
+		columns = utf8_strwidth(buf.buf);
+	strbuf_release(&buf);
+	return columns;
+}
+
+/*
+ * Given a buffer and its encoding, return it re-encoded
+ * with iconv.  If the conversion fails, returns NULL.
+ */
+#ifndef NO_ICONV
+#if defined(OLD_ICONV) || (defined(__sun__) && !defined(_XPG6))
+	typedef const char * iconv_ibp;
+#else
+	typedef char * iconv_ibp;
+#endif
+char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv,
+			    size_t bom_len, size_t *outsz_p)
+{
+	size_t outsz, outalloc;
+	char *out, *outpos;
+	iconv_ibp cp;
+
+	outsz = insz;
+	outalloc = st_add(outsz, 1 + bom_len); /* for terminating NUL */
+	out = xmalloc(outalloc);
+	outpos = out + bom_len;
+	cp = (iconv_ibp)in;
+
+	while (1) {
+		size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
+
+		if (cnt == (size_t) -1) {
+			size_t sofar;
+			if (errno != E2BIG) {
+				free(out);
+				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 = st_add3(sofar, st_mult(insz, 2), 32);
+			out = xrealloc(out, outalloc);
+			outpos = out + sofar;
+			outsz = outalloc - sofar - 1;
+		}
+		else {
+			*outpos = '\0';
+			if (outsz_p)
+				*outsz_p = outpos - out;
+			break;
+		}
+	}
+	return out;
+}
+
+static const char *fallback_encoding(const char *name)
+{
+	/*
+	 * Some platforms do not have the variously spelled variants of
+	 * UTF-8, so let's fall back to trying the most official
+	 * spelling. We do so only as a fallback in case the platform
+	 * does understand the user's spelling, but not our official
+	 * one.
+	 */
+	if (is_encoding_utf8(name))
+		return "UTF-8";
+
+	/*
+	 * Even though latin-1 is still seen in e-mail
+	 * headers, some platforms only install ISO-8859-1.
+	 */
+	if (!strcasecmp(name, "latin-1"))
+		return "ISO-8859-1";
+
+	return name;
+}
+
+char *reencode_string_len(const char *in, size_t insz,
+			  const char *out_encoding, const char *in_encoding,
+			  size_t *outsz)
+{
+	iconv_t conv;
+	char *out;
+	const char *bom_str = NULL;
+	size_t bom_len = 0;
+
+	if (!in_encoding)
+		return NULL;
+
+	/* UTF-16LE-BOM is the same as UTF-16 for reading */
+	if (same_utf_encoding("UTF-16LE-BOM", in_encoding))
+		in_encoding = "UTF-16";
+
+	/*
+	 * For writing, UTF-16 iconv typically creates "UTF-16BE-BOM"
+	 * Some users under Windows want the little endian version
+	 *
+	 * We handle UTF-16 and UTF-32 ourselves only if the platform does not
+	 * provide a BOM (which we require), since we want to match the behavior
+	 * of the system tools and libc as much as possible.
+	 */
+	if (same_utf_encoding("UTF-16LE-BOM", out_encoding)) {
+		bom_str = utf16_le_bom;
+		bom_len = sizeof(utf16_le_bom);
+		out_encoding = "UTF-16LE";
+	} else if (same_utf_encoding("UTF-16BE-BOM", out_encoding)) {
+		bom_str = utf16_be_bom;
+		bom_len = sizeof(utf16_be_bom);
+		out_encoding = "UTF-16BE";
+#ifdef ICONV_OMITS_BOM
+	} else if (same_utf_encoding("UTF-16", out_encoding)) {
+		bom_str = utf16_be_bom;
+		bom_len = sizeof(utf16_be_bom);
+		out_encoding = "UTF-16BE";
+	} else if (same_utf_encoding("UTF-32", out_encoding)) {
+		bom_str = utf32_be_bom;
+		bom_len = sizeof(utf32_be_bom);
+		out_encoding = "UTF-32BE";
+#endif
+	}
+
+	conv = iconv_open(out_encoding, in_encoding);
+	if (conv == (iconv_t) -1) {
+		in_encoding = fallback_encoding(in_encoding);
+		out_encoding = fallback_encoding(out_encoding);
+
+		conv = iconv_open(out_encoding, in_encoding);
+		if (conv == (iconv_t) -1)
+			return NULL;
+	}
+	out = reencode_string_iconv(in, insz, conv, bom_len, outsz);
+	iconv_close(conv);
+	if (out && bom_str && bom_len)
+		memcpy(out, bom_str, bom_len);
+	return out;
+}
+#endif
+
+static int has_bom_prefix(const char *data, size_t len,
+			  const char *bom, size_t bom_len)
+{
+	return data && bom && (len >= bom_len) && !memcmp(data, bom, bom_len);
+}
+
+int has_prohibited_utf_bom(const char *enc, const char *data, size_t len)
+{
+	return (
+	  (same_utf_encoding("UTF-16BE", enc) ||
+	   same_utf_encoding("UTF-16LE", enc)) &&
+	  (has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
+	   has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
+	) || (
+	  (same_utf_encoding("UTF-32BE",  enc) ||
+	   same_utf_encoding("UTF-32LE", enc)) &&
+	  (has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
+	   has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
+	);
+}
+
+int is_missing_required_utf_bom(const char *enc, const char *data, size_t len)
+{
+	return (
+	   (same_utf_encoding(enc, "UTF-16")) &&
+	   !(has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
+	     has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
+	) || (
+	   (same_utf_encoding(enc, "UTF-32")) &&
+	   !(has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
+	     has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
+	);
+}
+
+/*
+ * Returns first character length in bytes for multi-byte `text` according to
+ * `encoding`.
+ *
+ * - The `text` pointer is updated to point at the next character.
+ * - When `remainder_p` is not NULL, on entry `*remainder_p` is how much bytes
+ *   we can consume from text, and on exit `*remainder_p` is reduced by returned
+ *   character length. Otherwise `text` is treated as limited by NUL.
+ */
+int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding)
+{
+	int chrlen;
+	const char *p = *text;
+	size_t r = (remainder_p ? *remainder_p : SIZE_MAX);
+
+	if (r < 1)
+		return 0;
+
+	if (is_encoding_utf8(encoding)) {
+		pick_one_utf8_char(&p, &r);
+
+		chrlen = p ? (p - *text)
+			   : 1 /* not valid UTF-8 -> raw byte sequence */;
+	}
+	else {
+		/*
+		 * TODO use iconv to decode one char and obtain its chrlen
+		 * for now, let's treat encodings != UTF-8 as one-byte
+		 */
+		chrlen = 1;
+	}
+
+	*text += chrlen;
+	if (remainder_p)
+		*remainder_p -= chrlen;
+
+	return chrlen;
+}
+
+/*
+ * Pick the next char from the stream, ignoring codepoints an HFS+ would.
+ * Note that this is _not_ complete by any means. It's just enough
+ * to make is_hfs_dotgit() work, and should not be used otherwise.
+ */
+static ucs_char_t next_hfs_char(const char **in)
+{
+	while (1) {
+		ucs_char_t out = pick_one_utf8_char(in, NULL);
+		/*
+		 * check for malformed utf8. Technically this
+		 * gets converted to a percent-sequence, but
+		 * returning 0 is good enough for is_hfs_dotgit
+		 * to realize it cannot be .git
+		 */
+		if (!*in)
+			return 0;
+
+		/* these code points are ignored completely */
+		switch (out) {
+		case 0x200c: /* ZERO WIDTH NON-JOINER */
+		case 0x200d: /* ZERO WIDTH JOINER */
+		case 0x200e: /* LEFT-TO-RIGHT MARK */
+		case 0x200f: /* RIGHT-TO-LEFT MARK */
+		case 0x202a: /* LEFT-TO-RIGHT EMBEDDING */
+		case 0x202b: /* RIGHT-TO-LEFT EMBEDDING */
+		case 0x202c: /* POP DIRECTIONAL FORMATTING */
+		case 0x202d: /* LEFT-TO-RIGHT OVERRIDE */
+		case 0x202e: /* RIGHT-TO-LEFT OVERRIDE */
+		case 0x206a: /* INHIBIT SYMMETRIC SWAPPING */
+		case 0x206b: /* ACTIVATE SYMMETRIC SWAPPING */
+		case 0x206c: /* INHIBIT ARABIC FORM SHAPING */
+		case 0x206d: /* ACTIVATE ARABIC FORM SHAPING */
+		case 0x206e: /* NATIONAL DIGIT SHAPES */
+		case 0x206f: /* NOMINAL DIGIT SHAPES */
+		case 0xfeff: /* ZERO WIDTH NO-BREAK SPACE */
+			continue;
+		}
+
+		return out;
+	}
+}
+
+static int is_hfs_dot_generic(const char *path,
+			      const char *needle, size_t needle_len)
+{
+	ucs_char_t c;
+
+	c = next_hfs_char(&path);
+	if (c != '.')
+		return 0;
+
+	/*
+	 * there's a great deal of other case-folding that occurs
+	 * in HFS+, but this is enough to catch our fairly vanilla
+	 * hard-coded needles.
+	 */
+	for (; needle_len > 0; needle++, needle_len--) {
+		c = next_hfs_char(&path);
+
+		/*
+		 * We know our needles contain only ASCII, so we clamp here to
+		 * make the results of tolower() sane.
+		 */
+		if (c > 127)
+			return 0;
+		if (tolower(c) != *needle)
+			return 0;
+	}
+
+	c = next_hfs_char(&path);
+	if (c && !is_dir_sep(c))
+		return 0;
+
+	return 1;
+}
+
+/*
+ * Inline wrapper to make sure the compiler resolves strlen() on literals at
+ * compile time.
+ */
+static inline int is_hfs_dot_str(const char *path, const char *needle)
+{
+	return is_hfs_dot_generic(path, needle, strlen(needle));
+}
+
+int is_hfs_dotgit(const char *path)
+{
+	return is_hfs_dot_str(path, "git");
+}
+
+int is_hfs_dotgitmodules(const char *path)
+{
+	return is_hfs_dot_str(path, "gitmodules");
+}
+
+int is_hfs_dotgitignore(const char *path)
+{
+	return is_hfs_dot_str(path, "gitignore");
+}
+
+int is_hfs_dotgitattributes(const char *path)
+{
+	return is_hfs_dot_str(path, "gitattributes");
+}
+
+int is_hfs_dotmailmap(const char *path)
+{
+	return is_hfs_dot_str(path, "mailmap");
+}
+
+const char utf8_bom[] = "\357\273\277";
+
+int skip_utf8_bom(char **text, size_t len)
+{
+	if (len < strlen(utf8_bom) ||
+	    memcmp(*text, utf8_bom, strlen(utf8_bom)))
+		return 0;
+	*text += strlen(utf8_bom);
+	return 1;
+}
+
+void strbuf_utf8_align(struct strbuf *buf, align_type position, unsigned int width,
+		       const char *s)
+{
+	size_t slen = strlen(s);
+	int display_len = utf8_strnwidth(s, slen, 0);
+	int utf8_compensation = slen - display_len;
+
+	if (display_len >= width) {
+		strbuf_addstr(buf, s);
+		return;
+	}
+
+	if (position == ALIGN_LEFT)
+		strbuf_addf(buf, "%-*s", width + utf8_compensation, s);
+	else if (position == ALIGN_MIDDLE) {
+		int left = (width - display_len) / 2;
+		strbuf_addf(buf, "%*s%-*s", left, "", width - left + utf8_compensation, s);
+	} else if (position == ALIGN_RIGHT)
+		strbuf_addf(buf, "%*s", width + utf8_compensation, s);
+}