1 /*
2 * Copyright 2001-2004 Unicode, Inc.
3 *
4 * Disclaimer
5 *
6 * This source code is provided as is by Unicode, Inc. No claims are
7 * made as to fitness for any particular purpose. No warranties of any
8 * kind are expressed or implied. The recipient agrees to determine
9 * applicability of information provided. If this file has been
10 * purchased on magnetic or optical media from Unicode, Inc., the
11 * sole remedy for any claim will be exchange of defective media
12 * within 90 days of receipt.
13 *
14 * Limitations on Rights to Redistribute This Code
15 *
16 * Unicode, Inc. hereby grants the right to freely use the information
17 * supplied in this file in the creation of products supporting the
18 * Unicode Standard, and to make copies of this file in any form
19 * for internal or external distribution as long as this notice
20 * remains attached.
21 */
22
23 /* ---------------------------------------------------------------------
24
25 Conversions between UTF32, UTF-16, and UTF-8. Source code file.
26 Author: Mark E. Davis, 1994.
27 Rev History: Rick McGowan, fixes & updates May 2001.
28 Sept 2001: fixed const & error conditions per
29 mods suggested by S. Parent & A. Lillich.
30 June 2002: Tim Dodd added detection and handling of incomplete
31 source sequences, enhanced error detection, added casts
32 to eliminate compiler warnings.
33 July 2003: slight mods to back out aggressive FFFE detection.
34 Jan 2004: updated switches in from-UTF8 conversions.
35 Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions.
36
37 See the header file "ConvertUTF.h" for complete documentation.
38
39 ------------------------------------------------------------------------ */
40
41
42 #include "ConvertUTF.h"
43 #ifdef CVTUTF_DEBUG
44 #include <stdio.h>
45 #endif
46
47 static const int halfShift = 10; /* used for shifting by 10 bits */
48
49 static const UTF32 halfBase = 0x0010000UL;
50 static const UTF32 halfMask = 0x3FFUL;
51
52 #define UNI_SUR_HIGH_START (UTF32)0xD800
53 #define UNI_SUR_HIGH_END (UTF32)0xDBFF
54 #define UNI_SUR_LOW_START (UTF32)0xDC00
55 #define UNI_SUR_LOW_END (UTF32)0xDFFF
56 #define false 0
57 #define true 1
58
59 /* --------------------------------------------------------------------- */
60
ConvertUTF32toUTF16(const UTF32 ** sourceStart,const UTF32 * sourceEnd,UTF16 ** targetStart,UTF16 * targetEnd,ConversionFlags flags)61 ConversionResult ConvertUTF32toUTF16 (
62 const UTF32** sourceStart, const UTF32* sourceEnd,
63 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
64 ConversionResult result = conversionOK;
65 const UTF32* source = *sourceStart;
66 UTF16* target = *targetStart;
67 while (source < sourceEnd) {
68 UTF32 ch;
69 if (target >= targetEnd) {
70 result = targetExhausted; break;
71 }
72 ch = *source++;
73 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
74 /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */
75 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
76 if (flags == strictConversion) {
77 --source; /* return to the illegal value itself */
78 result = sourceIllegal;
79 break;
80 } else {
81 *target++ = UNI_REPLACEMENT_CHAR;
82 }
83 } else {
84 *target++ = (UTF16)ch; /* normal case */
85 }
86 } else if (ch > UNI_MAX_LEGAL_UTF32) {
87 if (flags == strictConversion) {
88 result = sourceIllegal;
89 } else {
90 *target++ = UNI_REPLACEMENT_CHAR;
91 }
92 } else {
93 /* target is a character in range 0xFFFF - 0x10FFFF. */
94 if (target + 1 >= targetEnd) {
95 --source; /* Back up source pointer! */
96 result = targetExhausted; break;
97 }
98 ch -= halfBase;
99 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
100 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
101 }
102 }
103 *sourceStart = source;
104 *targetStart = target;
105 return result;
106 }
107
108 /* --------------------------------------------------------------------- */
109
ConvertUTF16toUTF32(const UTF16 ** sourceStart,const UTF16 * sourceEnd,UTF32 ** targetStart,UTF32 * targetEnd,ConversionFlags flags)110 ConversionResult ConvertUTF16toUTF32 (
111 const UTF16** sourceStart, const UTF16* sourceEnd,
112 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
113 ConversionResult result = conversionOK;
114 const UTF16* source = *sourceStart;
115 UTF32* target = *targetStart;
116 UTF32 ch, ch2;
117 while (source < sourceEnd) {
118 const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
119 ch = *source++;
120 /* If we have a surrogate pair, convert to UTF32 first. */
121 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
122 /* If the 16 bits following the high surrogate are in the source buffer... */
123 if (source < sourceEnd) {
124 ch2 = *source;
125 /* If it's a low surrogate, convert to UTF32. */
126 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
127 ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
128 + (ch2 - UNI_SUR_LOW_START) + halfBase;
129 ++source;
130 } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
131 --source; /* return to the illegal value itself */
132 result = sourceIllegal;
133 break;
134 }
135 } else { /* We don't have the 16 bits following the high surrogate. */
136 --source; /* return to the high surrogate */
137 result = sourceExhausted;
138 break;
139 }
140 } else if (flags == strictConversion) {
141 /* UTF-16 surrogate values are illegal in UTF-32 */
142 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
143 --source; /* return to the illegal value itself */
144 result = sourceIllegal;
145 break;
146 }
147 }
148 if (target >= targetEnd) {
149 source = oldSource; /* Back up source pointer! */
150 result = targetExhausted; break;
151 }
152 *target++ = ch;
153 }
154 *sourceStart = source;
155 *targetStart = target;
156 #ifdef CVTUTF_DEBUG
157 if (result == sourceIllegal) {
158 fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2);
159 fflush(stderr);
160 }
161 #endif
162 return result;
163 }
164
165 /* --------------------------------------------------------------------- */
166
167 /*
168 * Index into the table below with the first byte of a UTF-8 sequence to
169 * get the number of trailing bytes that are supposed to follow it.
170 * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is
171 * left as-is for anyone who may want to do such conversion, which was
172 * allowed in earlier algorithms.
173 */
174 static const char trailingBytesForUTF8[256] = {
175 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
176 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
177 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
178 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
179 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
180 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
181 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
182 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
183 };
184
185 /*
186 * Magic values subtracted from a buffer value during UTF8 conversion.
187 * This table contains as many values as there might be trailing bytes
188 * in a UTF-8 sequence.
189 */
190 static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL,
191 0x03C82080UL, 0xFA082080UL, 0x82082080UL };
192
193 /*
194 * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
195 * into the first byte, depending on how many bytes follow. There are
196 * as many entries in this table as there are UTF-8 sequence types.
197 * (I.e., one byte sequence, two byte... etc.). Remember that sequencs
198 * for *legal* UTF-8 will be 4 or fewer bytes total.
199 */
200 static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
201
202 /* --------------------------------------------------------------------- */
203
204 /* The interface converts a whole buffer to avoid function-call overhead.
205 * Constants have been gathered. Loops & conditionals have been removed as
206 * much as possible for efficiency, in favor of drop-through switches.
207 * (See "Note A" at the bottom of the file for equivalent code.)
208 * If your compiler supports it, the "isLegalUTF8" call can be turned
209 * into an inline function.
210 */
211
212 /* --------------------------------------------------------------------- */
213
ConvertUTF16toUTF8(const UTF16 ** sourceStart,const UTF16 * sourceEnd,UTF8 ** targetStart,UTF8 * targetEnd,ConversionFlags flags)214 ConversionResult ConvertUTF16toUTF8 (
215 const UTF16** sourceStart, const UTF16* sourceEnd,
216 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
217 ConversionResult result = conversionOK;
218 const UTF16* source = *sourceStart;
219 UTF8* target = *targetStart;
220 while (source < sourceEnd) {
221 UTF32 ch;
222 unsigned short bytesToWrite = 0;
223 const UTF32 byteMask = 0xBF;
224 const UTF32 byteMark = 0x80;
225 const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
226 ch = *source++;
227 /* If we have a surrogate pair, convert to UTF32 first. */
228 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
229 /* If the 16 bits following the high surrogate are in the source buffer... */
230 if (source < sourceEnd) {
231 UTF32 ch2 = *source;
232 /* If it's a low surrogate, convert to UTF32. */
233 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
234 ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
235 + (ch2 - UNI_SUR_LOW_START) + halfBase;
236 ++source;
237 } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
238 --source; /* return to the illegal value itself */
239 result = sourceIllegal;
240 break;
241 }
242 } else { /* We don't have the 16 bits following the high surrogate. */
243 --source; /* return to the high surrogate */
244 result = sourceExhausted;
245 break;
246 }
247 } else if (flags == strictConversion) {
248 /* UTF-16 surrogate values are illegal in UTF-32 */
249 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
250 --source; /* return to the illegal value itself */
251 result = sourceIllegal;
252 break;
253 }
254 }
255
256 // TPN: substitute all control characters except for NULL, TAB, LF or CR
257 if (ch && (ch != (UTF32)0x09) && (ch != (UTF32)0x0a) && (ch != (UTF32)0x0d) && (ch < (UTF32)0x20) ) {
258 ch = (UTF32)0x3f;
259 }
260 // TPN: filter out byte order marks and invalid character 0xFFFF
261 if((ch == (UTF32)0xFEFF) || (ch == (UTF32)0xFFFE)|| (ch == (UTF32)0xFFFF)) {
262 continue;
263 }
264
265 /* Figure out how many bytes the result will require */
266 if (ch < (UTF32)0x80) { bytesToWrite = 1;
267 } else if (ch < (UTF32)0x800) { bytesToWrite = 2;
268 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3;
269 } else if (ch < (UTF32)0x110000) { bytesToWrite = 4;
270 } else { bytesToWrite = 3;
271 ch = UNI_REPLACEMENT_CHAR;
272 }
273
274 target += bytesToWrite;
275 if (target > targetEnd) {
276 source = oldSource; /* Back up source pointer! */
277 target -= bytesToWrite; result = targetExhausted; break;
278 }
279 switch (bytesToWrite) { /* note: everything falls through. */
280 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
281 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
282 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
283 case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]);
284 }
285 target += bytesToWrite;
286 }
287 *sourceStart = source;
288 *targetStart = target;
289 return result;
290 }
291
292 /* --------------------------------------------------------------------- */
293
294 /*
295 * Utility routine to tell whether a sequence of bytes is legal UTF-8.
296 * This must be called with the length pre-determined by the first byte.
297 * If not calling this from ConvertUTF8to*, then the length can be set by:
298 * length = trailingBytesForUTF8[*source]+1;
299 * and the sequence is illegal right away if there aren't that many bytes
300 * available.
301 * If presented with a length > 4, this returns false. The Unicode
302 * definition of UTF-8 goes up to 4-byte sequences.
303 */
304
isLegalUTF8(const UTF8 * source,int length)305 inline Boolean isLegalUTF8(const UTF8 *source, int length) {
306 UTF8 a;
307 const UTF8 *srcptr = source+length;
308 switch (length) {
309 default: return false;
310 /* Everything else falls through when "true"... */
311 case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
312 case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
313 case 2: if ((a = (*--srcptr)) > 0xBF) return false;
314
315 switch (*source) {
316 /* no fall-through in this inner switch */
317 case 0xE0: if (a < 0xA0) return false; break;
318 case 0xED: if (a > 0x9F) return false; break;
319 case 0xF0: if (a < 0x90) return false; break;
320 case 0xF4: if (a > 0x8F) return false; break;
321 default: if (a < 0x80) return false;
322 }
323
324 case 1: if (*source >= 0x80 && *source < 0xC2) return false;
325 }
326 if (*source > 0xF4) return false;
327 return true;
328 }
329
330 /* --------------------------------------------------------------------- */
331
332 /*
333 * Exported function to return whether a UTF-8 sequence is legal or not.
334 * This is not used here; it's just exported.
335 */
isLegalUTF8Sequence(const UTF8 * source,const UTF8 * sourceEnd)336 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
337 int length = trailingBytesForUTF8[*source]+1;
338 if (source+length > sourceEnd) {
339 return false;
340 }
341 return isLegalUTF8(source, length);
342 }
343
344 /* --------------------------------------------------------------------- */
345
ConvertUTF8toUTF16(const UTF8 ** sourceStart,const UTF8 * sourceEnd,UTF16 ** targetStart,UTF16 * targetEnd,ConversionFlags flags)346 ConversionResult ConvertUTF8toUTF16 (
347 const UTF8** sourceStart, const UTF8* sourceEnd,
348 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
349 ConversionResult result = conversionOK;
350 const UTF8* source = *sourceStart;
351 UTF16* target = *targetStart;
352 while (source < sourceEnd) {
353 UTF32 ch = 0;
354 unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
355 if (source + extraBytesToRead >= sourceEnd) {
356 result = sourceExhausted; break;
357 }
358 /* Do this check whether lenient or strict */
359 if (! isLegalUTF8(source, extraBytesToRead+1)) {
360 result = sourceIllegal;
361 break;
362 }
363 /*
364 * The cases all fall through. See "Note A" below.
365 */
366 switch (extraBytesToRead) {
367 case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
368 case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
369 case 3: ch += *source++; ch <<= 6;
370 case 2: ch += *source++; ch <<= 6;
371 case 1: ch += *source++; ch <<= 6;
372 case 0: ch += *source++;
373 }
374 ch -= offsetsFromUTF8[extraBytesToRead];
375
376 if (target >= targetEnd) {
377 source -= (extraBytesToRead+1); /* Back up source pointer! */
378 result = targetExhausted; break;
379 }
380 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
381 /* UTF-16 surrogate values are illegal in UTF-32 */
382 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
383 if (flags == strictConversion) {
384 source -= (extraBytesToRead+1); /* return to the illegal value itself */
385 result = sourceIllegal;
386 break;
387 } else {
388 *target++ = UNI_REPLACEMENT_CHAR;
389 }
390 } else {
391 *target++ = (UTF16)ch; /* normal case */
392 }
393 } else if (ch > UNI_MAX_UTF16) {
394 if (flags == strictConversion) {
395 result = sourceIllegal;
396 source -= (extraBytesToRead+1); /* return to the start */
397 break; /* Bail out; shouldn't continue */
398 } else {
399 *target++ = UNI_REPLACEMENT_CHAR;
400 }
401 } else {
402 /* target is a character in range 0xFFFF - 0x10FFFF. */
403 if (target + 1 >= targetEnd) {
404 source -= (extraBytesToRead+1); /* Back up source pointer! */
405 result = targetExhausted; break;
406 }
407 ch -= halfBase;
408 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
409 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
410 }
411 }
412 *sourceStart = source;
413 *targetStart = target;
414 return result;
415 }
416
417 /* --------------------------------------------------------------------- */
418
ConvertUTF32toUTF8(const UTF32 ** sourceStart,const UTF32 * sourceEnd,UTF8 ** targetStart,UTF8 * targetEnd,ConversionFlags flags)419 ConversionResult ConvertUTF32toUTF8 (
420 const UTF32** sourceStart, const UTF32* sourceEnd,
421 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
422 ConversionResult result = conversionOK;
423 const UTF32* source = *sourceStart;
424 UTF8* target = *targetStart;
425 while (source < sourceEnd) {
426 UTF32 ch;
427 unsigned short bytesToWrite = 0;
428 const UTF32 byteMask = 0xBF;
429 const UTF32 byteMark = 0x80;
430 ch = *source++;
431 if (flags == strictConversion ) {
432 /* UTF-16 surrogate values are illegal in UTF-32 */
433 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
434 --source; /* return to the illegal value itself */
435 result = sourceIllegal;
436 break;
437 }
438 }
439 /*
440 * Figure out how many bytes the result will require. Turn any
441 * illegally large UTF32 things (> Plane 17) into replacement chars.
442 */
443 if (ch < (UTF32)0x80) { bytesToWrite = 1;
444 } else if (ch < (UTF32)0x800) { bytesToWrite = 2;
445 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3;
446 } else if (ch <= UNI_MAX_LEGAL_UTF32) { bytesToWrite = 4;
447 } else { bytesToWrite = 3;
448 ch = UNI_REPLACEMENT_CHAR;
449 result = sourceIllegal;
450 }
451
452 target += bytesToWrite;
453 if (target > targetEnd) {
454 --source; /* Back up source pointer! */
455 target -= bytesToWrite; result = targetExhausted; break;
456 }
457 switch (bytesToWrite) { /* note: everything falls through. */
458 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
459 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
460 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
461 case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]);
462 }
463 target += bytesToWrite;
464 }
465 *sourceStart = source;
466 *targetStart = target;
467 return result;
468 }
469
470 /* --------------------------------------------------------------------- */
471
ConvertUTF8toUTF32(const UTF8 ** sourceStart,const UTF8 * sourceEnd,UTF32 ** targetStart,UTF32 * targetEnd,ConversionFlags flags)472 ConversionResult ConvertUTF8toUTF32 (
473 const UTF8** sourceStart, const UTF8* sourceEnd,
474 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
475 ConversionResult result = conversionOK;
476 const UTF8* source = *sourceStart;
477 UTF32* target = *targetStart;
478 while (source < sourceEnd) {
479 UTF32 ch = 0;
480 unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
481 if (source + extraBytesToRead >= sourceEnd) {
482 result = sourceExhausted; break;
483 }
484 /* Do this check whether lenient or strict */
485 if (! isLegalUTF8(source, extraBytesToRead+1)) {
486 result = sourceIllegal;
487 break;
488 }
489 /*
490 * The cases all fall through. See "Note A" below.
491 */
492 switch (extraBytesToRead) {
493 case 5: ch += *source++; ch <<= 6;
494 case 4: ch += *source++; ch <<= 6;
495 case 3: ch += *source++; ch <<= 6;
496 case 2: ch += *source++; ch <<= 6;
497 case 1: ch += *source++; ch <<= 6;
498 case 0: ch += *source++;
499 }
500 ch -= offsetsFromUTF8[extraBytesToRead];
501
502 if (target >= targetEnd) {
503 source -= (extraBytesToRead+1); /* Back up the source pointer! */
504 result = targetExhausted; break;
505 }
506 if (ch <= UNI_MAX_LEGAL_UTF32) {
507 /*
508 * UTF-16 surrogate values are illegal in UTF-32, and anything
509 * over Plane 17 (> 0x10FFFF) is illegal.
510 */
511 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
512 if (flags == strictConversion) {
513 source -= (extraBytesToRead+1); /* return to the illegal value itself */
514 result = sourceIllegal;
515 break;
516 } else {
517 *target++ = UNI_REPLACEMENT_CHAR;
518 }
519 } else {
520 *target++ = ch;
521 }
522 } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */
523 result = sourceIllegal;
524 *target++ = UNI_REPLACEMENT_CHAR;
525 }
526 }
527 *sourceStart = source;
528 *targetStart = target;
529 return result;
530 }
531
532 /* ---------------------------------------------------------------------
533
534 Note A.
535 The fall-through switches in UTF-8 reading code save a
536 temp variable, some decrements & conditionals. The switches
537 are equivalent to the following loop:
538 {
539 int tmpBytesToRead = extraBytesToRead+1;
540 do {
541 ch += *source++;
542 --tmpBytesToRead;
543 if (tmpBytesToRead) ch <<= 6;
544 } while (tmpBytesToRead > 0);
545 }
546 In UTF-8 writing code, the switches on "bytesToWrite" are
547 similarly unrolled loops.
548
549 --------------------------------------------------------------------- */
550