git

1
#include "git-compat-util.h"
2
#include "strbuf.h"
3
#include "utf8.h"
4

5
/* This code is originally from https://www.cl.cam.ac.uk/~mgk25/ucs/ */
6

7
static const char utf16_be_bom[] = {'\xFE', '\xFF'};
8
static const char utf16_le_bom[] = {'\xFF', '\xFE'};
9
static const char utf32_be_bom[] = {'\0', '\0', '\xFE', '\xFF'};
10
static const char utf32_le_bom[] = {'\xFF', '\xFE', '\0', '\0'};
11

12
struct interval {
13
	ucs_char_t first;
14
	ucs_char_t last;
15
};
16

17
size_t display_mode_esc_sequence_len(const char *s)
18
{
19
	const char *p = s;
20
	if (*p++ != '\033')
21
		return 0;
22
	if (*p++ != '[')
23
		return 0;
24
	while (isdigit(*p) || *p == ';')
25
		p++;
26
	if (*p++ != 'm')
27
		return 0;
28
	return p - s;
29
}
30

31
/* auxiliary function for binary search in interval table */
32
static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
33
{
34
	int min = 0;
35
	int mid;
36

37
	if (ucs < table[0].first || ucs > table[max].last)
38
		return 0;
39
	while (max >= min) {
40
		mid = min + (max - min) / 2;
41
		if (ucs > table[mid].last)
42
			min = mid + 1;
43
		else if (ucs < table[mid].first)
44
			max = mid - 1;
45
		else
46
			return 1;
47
	}
48

49
	return 0;
50
}
51

52
/* The following two functions define the column width of an ISO 10646
53
 * character as follows:
54
 *
55
 *    - The null character (U+0000) has a column width of 0.
56
 *
57
 *    - Other C0/C1 control characters and DEL will lead to a return
58
 *      value of -1.
59
 *
60
 *    - Non-spacing and enclosing combining characters (general
61
 *      category code Mn or Me in the Unicode database) have a
62
 *      column width of 0.
63
 *
64
 *    - SOFT HYPHEN (U+00AD) has a column width of 1.
65
 *
66
 *    - Other format characters (general category code Cf in the Unicode
67
 *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
68
 *
69
 *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
70
 *      have a column width of 0.
71
 *
72
 *    - Spacing characters in the East Asian Wide (W) or East Asian
73
 *      Full-width (F) category as defined in Unicode Technical
74
 *      Report #11 have a column width of 2.
75
 *
76
 *    - All remaining characters (including all printable
77
 *      ISO 8859-1 and WGL4 characters, Unicode control characters,
78
 *      etc.) have a column width of 1.
79
 *
80
 * This implementation assumes that ucs_char_t characters are encoded
81
 * in ISO 10646.
82
 */
83

84
static int git_wcwidth(ucs_char_t ch)
85
{
86
	/*
87
	 * Sorted list of non-overlapping intervals of non-spacing characters,
88
	 */
89
#include "unicode-width.h"
90

91
	/* test for 8-bit control characters */
92
	if (ch == 0)
93
		return 0;
94
	if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
95
		return -1;
96

97
	/* binary search in table of non-spacing characters */
98
	if (bisearch(ch, zero_width, ARRAY_SIZE(zero_width) - 1))
99
		return 0;
100

101
	/* binary search in table of double width characters */
102
	if (bisearch(ch, double_width, ARRAY_SIZE(double_width) - 1))
103
		return 2;
104

105
	return 1;
106
}
107

108
/*
109
 * Pick one ucs character starting from the location *start points at,
110
 * and return it, while updating the *start pointer to point at the
111
 * end of that character.  When remainder_p is not NULL, the location
112
 * holds the number of bytes remaining in the string that we are allowed
113
 * to pick from.  Otherwise we are allowed to pick up to the NUL that
114
 * would eventually appear in the string.  *remainder_p is also reduced
115
 * by the number of bytes we have consumed.
116
 *
117
 * If the string was not a valid UTF-8, *start pointer is set to NULL
118
 * and the return value is undefined.
119
 */
120
static ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
121
{
122
	unsigned char *s = (unsigned char *)*start;
123
	ucs_char_t ch;
124
	size_t remainder, incr;
125

126
	/*
127
	 * A caller that assumes NUL terminated text can choose
128
	 * not to bother with the remainder length.  We will
129
	 * stop at the first NUL.
130
	 */
131
	remainder = (remainder_p ? *remainder_p : 999);
132

133
	if (remainder < 1) {
134
		goto invalid;
135
	} else if (*s < 0x80) {
136
		/* 0xxxxxxx */
137
		ch = *s;
138
		incr = 1;
139
	} else if ((s[0] & 0xe0) == 0xc0) {
140
		/* 110XXXXx 10xxxxxx */
141
		if (remainder < 2 ||
142
		    (s[1] & 0xc0) != 0x80 ||
143
		    (s[0] & 0xfe) == 0xc0)
144
			goto invalid;
145
		ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
146
		incr = 2;
147
	} else if ((s[0] & 0xf0) == 0xe0) {
148
		/* 1110XXXX 10Xxxxxx 10xxxxxx */
149
		if (remainder < 3 ||
150
		    (s[1] & 0xc0) != 0x80 ||
151
		    (s[2] & 0xc0) != 0x80 ||
152
		    /* overlong? */
153
		    (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
154
		    /* surrogate? */
155
		    (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
156
		    /* U+FFFE or U+FFFF? */
157
		    (s[0] == 0xef && s[1] == 0xbf &&
158
		     (s[2] & 0xfe) == 0xbe))
159
			goto invalid;
160
		ch = ((s[0] & 0x0f) << 12) |
161
			((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
162
		incr = 3;
163
	} else if ((s[0] & 0xf8) == 0xf0) {
164
		/* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
165
		if (remainder < 4 ||
166
		    (s[1] & 0xc0) != 0x80 ||
167
		    (s[2] & 0xc0) != 0x80 ||
168
		    (s[3] & 0xc0) != 0x80 ||
169
		    /* overlong? */
170
		    (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
171
		    /* > U+10FFFF? */
172
		    (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
173
			goto invalid;
174
		ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
175
			((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
176
		incr = 4;
177
	} else {
178
invalid:
179
		*start = NULL;
180
		return 0;
181
	}
182

183
	*start += incr;
184
	if (remainder_p)
185
		*remainder_p = remainder - incr;
186
	return ch;
187
}
188

189
/*
190
 * This function returns the number of columns occupied by the character
191
 * pointed to by the variable start. The pointer is updated to point at
192
 * the next character. When remainder_p is not NULL, it points at the
193
 * location that stores the number of remaining bytes we can use to pick
194
 * a character (see pick_one_utf8_char() above).
195
 */
196
int utf8_width(const char **start, size_t *remainder_p)
197
{
198
	ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
199
	if (!*start)
200
		return 0;
201
	return git_wcwidth(ch);
202
}
203

204
/*
205
 * Returns the total number of columns required by a null-terminated
206
 * string, assuming that the string is utf8.  Returns strlen() instead
207
 * if the string does not look like a valid utf8 string.
208
 */
209
int utf8_strnwidth(const char *string, size_t len, int skip_ansi)
210
{
211
	const char *orig = string;
212
	size_t width = 0;
213

214
	while (string && string < orig + len) {
215
		int glyph_width;
216
		size_t skip;
217

218
		while (skip_ansi &&
219
		       (skip = display_mode_esc_sequence_len(string)) != 0)
220
			string += skip;
221

222
		glyph_width = utf8_width(&string, NULL);
223
		if (glyph_width > 0)
224
			width += glyph_width;
225
	}
226

227
	/*
228
	 * TODO: fix the interface of this function and `utf8_strwidth()` to
229
	 * return `size_t` instead of `int`.
230
	 */
231
	return cast_size_t_to_int(string ? width : len);
232
}
233

234
int utf8_strwidth(const char *string)
235
{
236
	return utf8_strnwidth(string, strlen(string), 0);
237
}
238

239
int is_utf8(const char *text)
240
{
241
	while (*text) {
242
		if (*text == '\n' || *text == '\t' || *text == '\r') {
243
			text++;
244
			continue;
245
		}
246
		utf8_width(&text, NULL);
247
		if (!text)
248
			return 0;
249
	}
250
	return 1;
251
}
252

253
static void strbuf_add_indented_text(struct strbuf *buf, const char *text,
254
				     int indent, int indent2)
255
{
256
	if (indent < 0)
257
		indent = 0;
258
	while (*text) {
259
		const char *eol = strchrnul(text, '\n');
260
		if (*eol == '\n')
261
			eol++;
262
		strbuf_addchars(buf, ' ', indent);
263
		strbuf_add(buf, text, eol - text);
264
		text = eol;
265
		indent = indent2;
266
	}
267
}
268

269
/*
270
 * Wrap the text, if necessary. The variable indent is the indent for the
271
 * first line, indent2 is the indent for all other lines.
272
 * If indent is negative, assume that already -indent columns have been
273
 * consumed (and no extra indent is necessary for the first line).
274
 */
275
void strbuf_add_wrapped_text(struct strbuf *buf,
276
		const char *text, int indent1, int indent2, int width)
277
{
278
	int indent, w, assume_utf8 = 1;
279
	const char *bol, *space, *start = text;
280
	size_t orig_len = buf->len;
281

282
	if (width <= 0) {
283
		strbuf_add_indented_text(buf, text, indent1, indent2);
284
		return;
285
	}
286

287
retry:
288
	bol = text;
289
	w = indent = indent1;
290
	space = NULL;
291
	if (indent < 0) {
292
		w = -indent;
293
		space = text;
294
	}
295

296
	for (;;) {
297
		char c;
298
		size_t skip;
299

300
		while ((skip = display_mode_esc_sequence_len(text)))
301
			text += skip;
302

303
		c = *text;
304
		if (!c || isspace(c)) {
305
			if (w <= width || !space) {
306
				const char *start = bol;
307
				if (!c && text == start)
308
					return;
309
				if (space)
310
					start = space;
311
				else
312
					strbuf_addchars(buf, ' ', indent);
313
				strbuf_add(buf, start, text - start);
314
				if (!c)
315
					return;
316
				space = text;
317
				if (c == '\t')
318
					w |= 0x07;
319
				else if (c == '\n') {
320
					space++;
321
					if (*space == '\n') {
322
						strbuf_addch(buf, '\n');
323
						goto new_line;
324
					}
325
					else if (!isalnum(*space))
326
						goto new_line;
327
					else
328
						strbuf_addch(buf, ' ');
329
				}
330
				w++;
331
				text++;
332
			}
333
			else {
334
new_line:
335
				strbuf_addch(buf, '\n');
336
				text = bol = space + isspace(*space);
337
				space = NULL;
338
				w = indent = indent2;
339
			}
340
			continue;
341
		}
342
		if (assume_utf8) {
343
			w += utf8_width(&text, NULL);
344
			if (!text) {
345
				assume_utf8 = 0;
346
				text = start;
347
				strbuf_setlen(buf, orig_len);
348
				goto retry;
349
			}
350
		} else {
351
			w++;
352
			text++;
353
		}
354
	}
355
}
356

357
void strbuf_add_wrapped_bytes(struct strbuf *buf, const char *data, int len,
358
			     int indent, int indent2, int width)
359
{
360
	char *tmp = xstrndup(data, len);
361
	strbuf_add_wrapped_text(buf, tmp, indent, indent2, width);
362
	free(tmp);
363
}
364

365
void strbuf_utf8_replace(struct strbuf *sb_src, int pos, int width,
366
			 const char *subst)
367
{
368
	const char *src = sb_src->buf, *end = sb_src->buf + sb_src->len;
369
	struct strbuf dst;
370
	int w = 0;
371

372
	strbuf_init(&dst, sb_src->len);
373

374
	while (src < end) {
375
		const char *old;
376
		int glyph_width;
377
		size_t n;
378

379
		while ((n = display_mode_esc_sequence_len(src))) {
380
			strbuf_add(&dst, src, n);
381
			src += n;
382
		}
383

384
		if (src >= end)
385
			break;
386

387
		old = src;
388
		glyph_width = utf8_width((const char**)&src, NULL);
389
		if (!src) /* broken utf-8, do nothing */
390
			goto out;
391

392
		/*
393
		 * In case we see a control character we copy it into the
394
		 * buffer, but don't add it to the width.
395
		 */
396
		if (glyph_width < 0)
397
			glyph_width = 0;
398

399
		if (glyph_width && w >= pos && w < pos + width) {
400
			if (subst) {
401
				strbuf_addstr(&dst, subst);
402
				subst = NULL;
403
			}
404
		} else {
405
			strbuf_add(&dst, old, src - old);
406
		}
407

408
		w += glyph_width;
409
	}
410

411
	strbuf_swap(sb_src, &dst);
412
out:
413
	strbuf_release(&dst);
414
}
415

416
/*
417
 * Returns true (1) if the src encoding name matches the dst encoding
418
 * name directly or one of its alternative names. E.g. UTF-16BE is the
419
 * same as UTF16BE.
420
 */
421
static int same_utf_encoding(const char *src, const char *dst)
422
{
423
	if (skip_iprefix(src, "utf", &src) && skip_iprefix(dst, "utf", &dst)) {
424
		skip_prefix(src, "-", &src);
425
		skip_prefix(dst, "-", &dst);
426
		return !strcasecmp(src, dst);
427
	}
428
	return 0;
429
}
430

431
int is_encoding_utf8(const char *name)
432
{
433
	if (!name)
434
		return 1;
435
	if (same_utf_encoding("utf-8", name))
436
		return 1;
437
	return 0;
438
}
439

440
int same_encoding(const char *src, const char *dst)
441
{
442
	static const char utf8[] = "UTF-8";
443

444
	if (!src)
445
		src = utf8;
446
	if (!dst)
447
		dst = utf8;
448
	if (same_utf_encoding(src, dst))
449
		return 1;
450
	return !strcasecmp(src, dst);
451
}
452

453
/*
454
 * Wrapper for fprintf and returns the total number of columns required
455
 * for the printed string, assuming that the string is utf8.
456
 */
457
int utf8_fprintf(FILE *stream, const char *format, ...)
458
{
459
	struct strbuf buf = STRBUF_INIT;
460
	va_list arg;
461
	int columns;
462

463
	va_start(arg, format);
464
	strbuf_vaddf(&buf, format, arg);
465
	va_end(arg);
466

467
	columns = fputs(buf.buf, stream);
468
	if (0 <= columns) /* keep the error from the I/O */
469
		columns = utf8_strwidth(buf.buf);
470
	strbuf_release(&buf);
471
	return columns;
472
}
473

474
/*
475
 * Given a buffer and its encoding, return it re-encoded
476
 * with iconv.  If the conversion fails, returns NULL.
477
 */
478
#ifndef NO_ICONV
479
#if defined(OLD_ICONV) || (defined(__sun__) && !defined(_XPG6))
480
	typedef const char * iconv_ibp;
481
#else
482
	typedef char * iconv_ibp;
483
#endif
484
char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv,
485
			    size_t bom_len, size_t *outsz_p)
486
{
487
	size_t outsz, outalloc;
488
	char *out, *outpos;
489
	iconv_ibp cp;
490

491
	outsz = insz;
492
	outalloc = st_add(outsz, 1 + bom_len); /* for terminating NUL */
493
	out = xmalloc(outalloc);
494
	outpos = out + bom_len;
495
	cp = (iconv_ibp)in;
496

497
	while (1) {
498
		size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
499

500
		if (cnt == (size_t) -1) {
501
			size_t sofar;
502
			if (errno != E2BIG) {
503
				free(out);
504
				return NULL;
505
			}
506
			/* insz has remaining number of bytes.
507
			 * since we started outsz the same as insz,
508
			 * it is likely that insz is not enough for
509
			 * converting the rest.
510
			 */
511
			sofar = outpos - out;
512
			outalloc = st_add3(sofar, st_mult(insz, 2), 32);
513
			out = xrealloc(out, outalloc);
514
			outpos = out + sofar;
515
			outsz = outalloc - sofar - 1;
516
		}
517
		else {
518
			*outpos = '\0';
519
			if (outsz_p)
520
				*outsz_p = outpos - out;
521
			break;
522
		}
523
	}
524
	return out;
525
}
526

527
static const char *fallback_encoding(const char *name)
528
{
529
	/*
530
	 * Some platforms do not have the variously spelled variants of
531
	 * UTF-8, so let's fall back to trying the most official
532
	 * spelling. We do so only as a fallback in case the platform
533
	 * does understand the user's spelling, but not our official
534
	 * one.
535
	 */
536
	if (is_encoding_utf8(name))
537
		return "UTF-8";
538

539
	/*
540
	 * Even though latin-1 is still seen in e-mail
541
	 * headers, some platforms only install ISO-8859-1.
542
	 */
543
	if (!strcasecmp(name, "latin-1"))
544
		return "ISO-8859-1";
545

546
	return name;
547
}
548

549
char *reencode_string_len(const char *in, size_t insz,
550
			  const char *out_encoding, const char *in_encoding,
551
			  size_t *outsz)
552
{
553
	iconv_t conv;
554
	char *out;
555
	const char *bom_str = NULL;
556
	size_t bom_len = 0;
557

558
	if (!in_encoding)
559
		return NULL;
560

561
	/* UTF-16LE-BOM is the same as UTF-16 for reading */
562
	if (same_utf_encoding("UTF-16LE-BOM", in_encoding))
563
		in_encoding = "UTF-16";
564

565
	/*
566
	 * For writing, UTF-16 iconv typically creates "UTF-16BE-BOM"
567
	 * Some users under Windows want the little endian version
568
	 *
569
	 * We handle UTF-16 and UTF-32 ourselves only if the platform does not
570
	 * provide a BOM (which we require), since we want to match the behavior
571
	 * of the system tools and libc as much as possible.
572
	 */
573
	if (same_utf_encoding("UTF-16LE-BOM", out_encoding)) {
574
		bom_str = utf16_le_bom;
575
		bom_len = sizeof(utf16_le_bom);
576
		out_encoding = "UTF-16LE";
577
	} else if (same_utf_encoding("UTF-16BE-BOM", out_encoding)) {
578
		bom_str = utf16_be_bom;
579
		bom_len = sizeof(utf16_be_bom);
580
		out_encoding = "UTF-16BE";
581
#ifdef ICONV_OMITS_BOM
582
	} else if (same_utf_encoding("UTF-16", out_encoding)) {
583
		bom_str = utf16_be_bom;
584
		bom_len = sizeof(utf16_be_bom);
585
		out_encoding = "UTF-16BE";
586
	} else if (same_utf_encoding("UTF-32", out_encoding)) {
587
		bom_str = utf32_be_bom;
588
		bom_len = sizeof(utf32_be_bom);
589
		out_encoding = "UTF-32BE";
590
#endif
591
	}
592

593
	conv = iconv_open(out_encoding, in_encoding);
594
	if (conv == (iconv_t) -1) {
595
		in_encoding = fallback_encoding(in_encoding);
596
		out_encoding = fallback_encoding(out_encoding);
597

598
		conv = iconv_open(out_encoding, in_encoding);
599
		if (conv == (iconv_t) -1)
600
			return NULL;
601
	}
602
	out = reencode_string_iconv(in, insz, conv, bom_len, outsz);
603
	iconv_close(conv);
604
	if (out && bom_str && bom_len)
605
		memcpy(out, bom_str, bom_len);
606
	return out;
607
}
608
#endif
609

610
static int has_bom_prefix(const char *data, size_t len,
611
			  const char *bom, size_t bom_len)
612
{
613
	return data && bom && (len >= bom_len) && !memcmp(data, bom, bom_len);
614
}
615

616
int has_prohibited_utf_bom(const char *enc, const char *data, size_t len)
617
{
618
	return (
619
	  (same_utf_encoding("UTF-16BE", enc) ||
620
	   same_utf_encoding("UTF-16LE", enc)) &&
621
	  (has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
622
	   has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
623
	) || (
624
	  (same_utf_encoding("UTF-32BE",  enc) ||
625
	   same_utf_encoding("UTF-32LE", enc)) &&
626
	  (has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
627
	   has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
628
	);
629
}
630

631
int is_missing_required_utf_bom(const char *enc, const char *data, size_t len)
632
{
633
	return (
634
	   (same_utf_encoding(enc, "UTF-16")) &&
635
	   !(has_bom_prefix(data, len, utf16_be_bom, sizeof(utf16_be_bom)) ||
636
	     has_bom_prefix(data, len, utf16_le_bom, sizeof(utf16_le_bom)))
637
	) || (
638
	   (same_utf_encoding(enc, "UTF-32")) &&
639
	   !(has_bom_prefix(data, len, utf32_be_bom, sizeof(utf32_be_bom)) ||
640
	     has_bom_prefix(data, len, utf32_le_bom, sizeof(utf32_le_bom)))
641
	);
642
}
643

644
/*
645
 * Returns first character length in bytes for multi-byte `text` according to
646
 * `encoding`.
647
 *
648
 * - The `text` pointer is updated to point at the next character.
649
 * - When `remainder_p` is not NULL, on entry `*remainder_p` is how much bytes
650
 *   we can consume from text, and on exit `*remainder_p` is reduced by returned
651
 *   character length. Otherwise `text` is treated as limited by NUL.
652
 */
653
int mbs_chrlen(const char **text, size_t *remainder_p, const char *encoding)
654
{
655
	int chrlen;
656
	const char *p = *text;
657
	size_t r = (remainder_p ? *remainder_p : SIZE_MAX);
658

659
	if (r < 1)
660
		return 0;
661

662
	if (is_encoding_utf8(encoding)) {
663
		pick_one_utf8_char(&p, &r);
664

665
		chrlen = p ? (p - *text)
666
			   : 1 /* not valid UTF-8 -> raw byte sequence */;
667
	}
668
	else {
669
		/*
670
		 * TODO use iconv to decode one char and obtain its chrlen
671
		 * for now, let's treat encodings != UTF-8 as one-byte
672
		 */
673
		chrlen = 1;
674
	}
675

676
	*text += chrlen;
677
	if (remainder_p)
678
		*remainder_p -= chrlen;
679

680
	return chrlen;
681
}
682

683
/*
684
 * Pick the next char from the stream, ignoring codepoints an HFS+ would.
685
 * Note that this is _not_ complete by any means. It's just enough
686
 * to make is_hfs_dotgit() work, and should not be used otherwise.
687
 */
688
static ucs_char_t next_hfs_char(const char **in)
689
{
690
	while (1) {
691
		ucs_char_t out = pick_one_utf8_char(in, NULL);
692
		/*
693
		 * check for malformed utf8. Technically this
694
		 * gets converted to a percent-sequence, but
695
		 * returning 0 is good enough for is_hfs_dotgit
696
		 * to realize it cannot be .git
697
		 */
698
		if (!*in)
699
			return 0;
700

701
		/* these code points are ignored completely */
702
		switch (out) {
703
		case 0x200c: /* ZERO WIDTH NON-JOINER */
704
		case 0x200d: /* ZERO WIDTH JOINER */
705
		case 0x200e: /* LEFT-TO-RIGHT MARK */
706
		case 0x200f: /* RIGHT-TO-LEFT MARK */
707
		case 0x202a: /* LEFT-TO-RIGHT EMBEDDING */
708
		case 0x202b: /* RIGHT-TO-LEFT EMBEDDING */
709
		case 0x202c: /* POP DIRECTIONAL FORMATTING */
710
		case 0x202d: /* LEFT-TO-RIGHT OVERRIDE */
711
		case 0x202e: /* RIGHT-TO-LEFT OVERRIDE */
712
		case 0x206a: /* INHIBIT SYMMETRIC SWAPPING */
713
		case 0x206b: /* ACTIVATE SYMMETRIC SWAPPING */
714
		case 0x206c: /* INHIBIT ARABIC FORM SHAPING */
715
		case 0x206d: /* ACTIVATE ARABIC FORM SHAPING */
716
		case 0x206e: /* NATIONAL DIGIT SHAPES */
717
		case 0x206f: /* NOMINAL DIGIT SHAPES */
718
		case 0xfeff: /* ZERO WIDTH NO-BREAK SPACE */
719
			continue;
720
		}
721

722
		return out;
723
	}
724
}
725

726
static int is_hfs_dot_generic(const char *path,
727
			      const char *needle, size_t needle_len)
728
{
729
	ucs_char_t c;
730

731
	c = next_hfs_char(&path);
732
	if (c != '.')
733
		return 0;
734

735
	/*
736
	 * there's a great deal of other case-folding that occurs
737
	 * in HFS+, but this is enough to catch our fairly vanilla
738
	 * hard-coded needles.
739
	 */
740
	for (; needle_len > 0; needle++, needle_len--) {
741
		c = next_hfs_char(&path);
742

743
		/*
744
		 * We know our needles contain only ASCII, so we clamp here to
745
		 * make the results of tolower() sane.
746
		 */
747
		if (c > 127)
748
			return 0;
749
		if (tolower(c) != *needle)
750
			return 0;
751
	}
752

753
	c = next_hfs_char(&path);
754
	if (c && !is_dir_sep(c))
755
		return 0;
756

757
	return 1;
758
}
759

760
/*
761
 * Inline wrapper to make sure the compiler resolves strlen() on literals at
762
 * compile time.
763
 */
764
static inline int is_hfs_dot_str(const char *path, const char *needle)
765
{
766
	return is_hfs_dot_generic(path, needle, strlen(needle));
767
}
768

769
int is_hfs_dotgit(const char *path)
770
{
771
	return is_hfs_dot_str(path, "git");
772
}
773

774
int is_hfs_dotgitmodules(const char *path)
775
{
776
	return is_hfs_dot_str(path, "gitmodules");
777
}
778

779
int is_hfs_dotgitignore(const char *path)
780
{
781
	return is_hfs_dot_str(path, "gitignore");
782
}
783

784
int is_hfs_dotgitattributes(const char *path)
785
{
786
	return is_hfs_dot_str(path, "gitattributes");
787
}
788

789
int is_hfs_dotmailmap(const char *path)
790
{
791
	return is_hfs_dot_str(path, "mailmap");
792
}
793

794
const char utf8_bom[] = "\357\273\277";
795

796
int skip_utf8_bom(char **text, size_t len)
797
{
798
	if (len < strlen(utf8_bom) ||
799
	    memcmp(*text, utf8_bom, strlen(utf8_bom)))
800
		return 0;
801
	*text += strlen(utf8_bom);
802
	return 1;
803
}
804

805
void strbuf_utf8_align(struct strbuf *buf, align_type position, unsigned int width,
806
		       const char *s)
807
{
808
	size_t slen = strlen(s);
809
	int display_len = utf8_strnwidth(s, slen, 0);
810
	int utf8_compensation = slen - display_len;
811

812
	if (display_len >= width) {
813
		strbuf_addstr(buf, s);
814
		return;
815
	}
816

817
	if (position == ALIGN_LEFT)
818
		strbuf_addf(buf, "%-*s", width + utf8_compensation, s);
819
	else if (position == ALIGN_MIDDLE) {
820
		int left = (width - display_len) / 2;
821
		strbuf_addf(buf, "%*s%-*s", left, "", width - left + utf8_compensation, s);
822
	} else if (position == ALIGN_RIGHT)
823
		strbuf_addf(buf, "%*s", width + utf8_compensation, s);
824
}
825