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1 /*
2  * Copyright (C) 2004, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
3  * Copyright (C) 2006 Alexey Proskuryakov <ap@nypop.com>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "config.h"
28 #include "TextCodecICU.h"
29 
30 #include "ThreadGlobalData.h"
31 #include <unicode/ucnv.h>
32 #include <unicode/ucnv_cb.h>
33 #include <wtf/Assertions.h>
34 #include <wtf/StringExtras.h>
35 #include <wtf/Threading.h>
36 #include <wtf/text/CString.h>
37 #include <wtf/unicode/CharacterNames.h>
38 
39 using std::min;
40 
41 namespace WebCore {
42 
43 const size_t ConversionBufferSize = 16384;
44 
~ICUConverterWrapper()45 ICUConverterWrapper::~ICUConverterWrapper()
46 {
47     if (converter)
48         ucnv_close(converter);
49 }
50 
cachedConverterICU()51 static UConverter*& cachedConverterICU()
52 {
53     return threadGlobalData().cachedConverterICU().converter;
54 }
55 
create(const TextEncoding & encoding,const void *)56 PassOwnPtr<TextCodec> TextCodecICU::create(const TextEncoding& encoding, const void*)
57 {
58     return adoptPtr(new TextCodecICU(encoding));
59 }
60 
registerEncodingNames(EncodingNameRegistrar registrar)61 void TextCodecICU::registerEncodingNames(EncodingNameRegistrar registrar)
62 {
63     // We register Hebrew with logical ordering using a separate name.
64     // Otherwise, this would share the same canonical name as the
65     // visual ordering case, and then TextEncoding could not tell them
66     // apart; ICU treats these names as synonyms.
67     registrar("ISO-8859-8-I", "ISO-8859-8-I");
68 
69     int32_t numEncodings = ucnv_countAvailable();
70     for (int32_t i = 0; i < numEncodings; ++i) {
71         const char* name = ucnv_getAvailableName(i);
72         UErrorCode error = U_ZERO_ERROR;
73         // Try MIME before trying IANA to pick up commonly used names like
74         // 'EUC-JP' instead of horrendously long names like
75         // 'Extended_UNIX_Code_Packed_Format_for_Japanese'.
76         const char* standardName = ucnv_getStandardName(name, "MIME", &error);
77         if (!U_SUCCESS(error) || !standardName) {
78             error = U_ZERO_ERROR;
79             // Try IANA to pick up 'windows-12xx' and other names
80             // which are not preferred MIME names but are widely used.
81             standardName = ucnv_getStandardName(name, "IANA", &error);
82             if (!U_SUCCESS(error) || !standardName)
83                 continue;
84         }
85 
86         // 1. Treat GB2312 encoding as GBK (its more modern superset), to match other browsers.
87         // 2. On the Web, GB2312 is encoded as EUC-CN or HZ, while ICU provides a native encoding
88         //    for encoding GB_2312-80 and several others. So, we need to override this behavior, too.
89         if (strcmp(standardName, "GB2312") == 0 || strcmp(standardName, "GB_2312-80") == 0)
90             standardName = "GBK";
91         // Similarly, EUC-KR encodings all map to an extended version.
92         else if (strcmp(standardName, "KSC_5601") == 0 || strcmp(standardName, "EUC-KR") == 0 || strcmp(standardName, "cp1363") == 0)
93             standardName = "windows-949";
94         // And so on.
95         else if (strcasecmp(standardName, "iso-8859-9") == 0) // This name is returned in different case by ICU 3.2 and 3.6.
96             standardName = "windows-1254";
97         else if (strcmp(standardName, "TIS-620") == 0)
98             standardName = "windows-874";
99 
100         registrar(standardName, standardName);
101 
102         uint16_t numAliases = ucnv_countAliases(name, &error);
103         ASSERT(U_SUCCESS(error));
104         if (U_SUCCESS(error))
105             for (uint16_t j = 0; j < numAliases; ++j) {
106                 error = U_ZERO_ERROR;
107                 const char* alias = ucnv_getAlias(name, j, &error);
108                 ASSERT(U_SUCCESS(error));
109                 if (U_SUCCESS(error) && alias != standardName)
110                     registrar(alias, standardName);
111             }
112     }
113 
114     // Additional aliases.
115     // These are present in modern versions of ICU, but not in ICU 3.2 (shipped with Mac OS X 10.4).
116     registrar("macroman", "macintosh");
117     registrar("maccyrillic", "x-mac-cyrillic");
118 
119     // Additional aliases that historically were present in the encoding
120     // table in WebKit on Macintosh that don't seem to be present in ICU.
121     // Perhaps we can prove these are not used on the web and remove them.
122     // Or perhaps we can get them added to ICU.
123     registrar("x-mac-roman", "macintosh");
124     registrar("x-mac-ukrainian", "x-mac-cyrillic");
125     registrar("cn-big5", "Big5");
126     registrar("x-x-big5", "Big5");
127     registrar("cn-gb", "GBK");
128     registrar("csgb231280", "GBK");
129     registrar("x-euc-cn", "GBK");
130     registrar("x-gbk", "GBK");
131     registrar("csISO88598I", "ISO-8859-8-I");
132     registrar("koi", "KOI8-R");
133     registrar("logical", "ISO-8859-8-I");
134     registrar("visual", "ISO-8859-8");
135     registrar("winarabic", "windows-1256");
136     registrar("winbaltic", "windows-1257");
137     registrar("wincyrillic", "windows-1251");
138     registrar("iso-8859-11", "windows-874");
139     registrar("iso8859-11", "windows-874");
140     registrar("dos-874", "windows-874");
141     registrar("wingreek", "windows-1253");
142     registrar("winhebrew", "windows-1255");
143     registrar("winlatin2", "windows-1250");
144     registrar("winturkish", "windows-1254");
145     registrar("winvietnamese", "windows-1258");
146     registrar("x-cp1250", "windows-1250");
147     registrar("x-cp1251", "windows-1251");
148     registrar("x-euc", "EUC-JP");
149     registrar("x-windows-949", "windows-949");
150     registrar("x-uhc", "windows-949");
151     registrar("shift-jis", "Shift_JIS");
152 
153     // These aliases are present in modern versions of ICU, but use different codecs, and have no standard names.
154     // They are not present in ICU 3.2.
155     registrar("dos-720", "cp864");
156     registrar("jis7", "ISO-2022-JP");
157 
158     // Alternative spelling of ISO encoding names.
159     registrar("ISO8859-1", "ISO-8859-1");
160     registrar("ISO8859-2", "ISO-8859-2");
161     registrar("ISO8859-3", "ISO-8859-3");
162     registrar("ISO8859-4", "ISO-8859-4");
163     registrar("ISO8859-5", "ISO-8859-5");
164     registrar("ISO8859-6", "ISO-8859-6");
165     registrar("ISO8859-7", "ISO-8859-7");
166     registrar("ISO8859-8", "ISO-8859-8");
167     registrar("ISO8859-8-I", "ISO-8859-8-I");
168     registrar("ISO8859-9", "ISO-8859-9");
169     registrar("ISO8859-10", "ISO-8859-10");
170     registrar("ISO8859-13", "ISO-8859-13");
171     registrar("ISO8859-14", "ISO-8859-14");
172     registrar("ISO8859-15", "ISO-8859-15");
173     // Not registering ISO8859-16, because Firefox (as of version 3.6.6) doesn't know this particular alias,
174     // and because older versions of ICU don't support ISO-8859-16 encoding at all.
175 }
176 
registerCodecs(TextCodecRegistrar registrar)177 void TextCodecICU::registerCodecs(TextCodecRegistrar registrar)
178 {
179     // See comment above in registerEncodingNames.
180     registrar("ISO-8859-8-I", create, 0);
181 
182     int32_t numEncodings = ucnv_countAvailable();
183     for (int32_t i = 0; i < numEncodings; ++i) {
184         const char* name = ucnv_getAvailableName(i);
185         UErrorCode error = U_ZERO_ERROR;
186         const char* standardName = ucnv_getStandardName(name, "MIME", &error);
187         if (!U_SUCCESS(error) || !standardName) {
188             error = U_ZERO_ERROR;
189             standardName = ucnv_getStandardName(name, "IANA", &error);
190             if (!U_SUCCESS(error) || !standardName)
191                 continue;
192         }
193         registrar(standardName, create, 0);
194     }
195 }
196 
TextCodecICU(const TextEncoding & encoding)197 TextCodecICU::TextCodecICU(const TextEncoding& encoding)
198     : m_encoding(encoding)
199     , m_numBufferedBytes(0)
200     , m_converterICU(0)
201     , m_needsGBKFallbacks(false)
202 {
203 }
204 
~TextCodecICU()205 TextCodecICU::~TextCodecICU()
206 {
207     releaseICUConverter();
208 }
209 
releaseICUConverter() const210 void TextCodecICU::releaseICUConverter() const
211 {
212     if (m_converterICU) {
213         UConverter*& cachedConverter = cachedConverterICU();
214         if (cachedConverter)
215             ucnv_close(cachedConverter);
216         cachedConverter = m_converterICU;
217         m_converterICU = 0;
218     }
219 }
220 
createICUConverter() const221 void TextCodecICU::createICUConverter() const
222 {
223     ASSERT(!m_converterICU);
224 
225     const char* name = m_encoding.name();
226     m_needsGBKFallbacks = name[0] == 'G' && name[1] == 'B' && name[2] == 'K' && !name[3];
227 
228     UErrorCode err;
229 
230     UConverter*& cachedConverter = cachedConverterICU();
231     if (cachedConverter) {
232         err = U_ZERO_ERROR;
233         const char* cachedName = ucnv_getName(cachedConverter, &err);
234         if (U_SUCCESS(err) && m_encoding == cachedName) {
235             m_converterICU = cachedConverter;
236             cachedConverter = 0;
237             return;
238         }
239     }
240 
241     err = U_ZERO_ERROR;
242     m_converterICU = ucnv_open(m_encoding.name(), &err);
243 #if !LOG_DISABLED
244     if (err == U_AMBIGUOUS_ALIAS_WARNING)
245         LOG_ERROR("ICU ambiguous alias warning for encoding: %s", m_encoding.name());
246 #endif
247     if (m_converterICU)
248         ucnv_setFallback(m_converterICU, TRUE);
249 }
250 
decodeToBuffer(UChar * target,UChar * targetLimit,const char * & source,const char * sourceLimit,int32_t * offsets,bool flush,UErrorCode & err)251 int TextCodecICU::decodeToBuffer(UChar* target, UChar* targetLimit, const char*& source, const char* sourceLimit, int32_t* offsets, bool flush, UErrorCode& err)
252 {
253     UChar* targetStart = target;
254     err = U_ZERO_ERROR;
255     ucnv_toUnicode(m_converterICU, &target, targetLimit, &source, sourceLimit, offsets, flush, &err);
256     return target - targetStart;
257 }
258 
259 class ErrorCallbackSetter {
260 public:
ErrorCallbackSetter(UConverter * converter,bool stopOnError)261     ErrorCallbackSetter(UConverter* converter, bool stopOnError)
262         : m_converter(converter)
263         , m_shouldStopOnEncodingErrors(stopOnError)
264     {
265         if (m_shouldStopOnEncodingErrors) {
266             UErrorCode err = U_ZERO_ERROR;
267             ucnv_setToUCallBack(m_converter, UCNV_TO_U_CALLBACK_SUBSTITUTE,
268                            UCNV_SUB_STOP_ON_ILLEGAL, &m_savedAction,
269                            &m_savedContext, &err);
270             ASSERT(err == U_ZERO_ERROR);
271         }
272     }
~ErrorCallbackSetter()273     ~ErrorCallbackSetter()
274     {
275         if (m_shouldStopOnEncodingErrors) {
276             UErrorCode err = U_ZERO_ERROR;
277             const void* oldContext;
278             UConverterToUCallback oldAction;
279             ucnv_setToUCallBack(m_converter, m_savedAction,
280                    m_savedContext, &oldAction,
281                    &oldContext, &err);
282             ASSERT(oldAction == UCNV_TO_U_CALLBACK_SUBSTITUTE);
283             ASSERT(!strcmp(static_cast<const char*>(oldContext), UCNV_SUB_STOP_ON_ILLEGAL));
284             ASSERT(err == U_ZERO_ERROR);
285         }
286     }
287 
288 private:
289     UConverter* m_converter;
290     bool m_shouldStopOnEncodingErrors;
291     const void* m_savedContext;
292     UConverterToUCallback m_savedAction;
293 };
294 
decode(const char * bytes,size_t length,bool flush,bool stopOnError,bool & sawError)295 String TextCodecICU::decode(const char* bytes, size_t length, bool flush, bool stopOnError, bool& sawError)
296 {
297     // Get a converter for the passed-in encoding.
298     if (!m_converterICU) {
299         createICUConverter();
300         ASSERT(m_converterICU);
301         if (!m_converterICU) {
302             LOG_ERROR("error creating ICU encoder even though encoding was in table");
303             return String();
304         }
305     }
306 
307     ErrorCallbackSetter callbackSetter(m_converterICU, stopOnError);
308 
309     Vector<UChar> result;
310 
311     UChar buffer[ConversionBufferSize];
312     UChar* bufferLimit = buffer + ConversionBufferSize;
313     const char* source = reinterpret_cast<const char*>(bytes);
314     const char* sourceLimit = source + length;
315     int32_t* offsets = NULL;
316     UErrorCode err = U_ZERO_ERROR;
317 
318     do {
319         int ucharsDecoded = decodeToBuffer(buffer, bufferLimit, source, sourceLimit, offsets, flush, err);
320         result.append(buffer, ucharsDecoded);
321     } while (err == U_BUFFER_OVERFLOW_ERROR);
322 
323     if (U_FAILURE(err)) {
324         // flush the converter so it can be reused, and not be bothered by this error.
325         do {
326             decodeToBuffer(buffer, bufferLimit, source, sourceLimit, offsets, true, err);
327         } while (source < sourceLimit);
328         sawError = true;
329     }
330 
331     String resultString = String::adopt(result);
332 
333     // <http://bugs.webkit.org/show_bug.cgi?id=17014>
334     // Simplified Chinese pages use the code A3A0 to mean "full-width space", but ICU decodes it as U+E5E5.
335     if (strcmp(m_encoding.name(), "GBK") == 0 || strcasecmp(m_encoding.name(), "gb18030") == 0)
336         resultString.replace(0xE5E5, ideographicSpace);
337 
338     return resultString;
339 }
340 
341 // We need to apply these fallbacks ourselves as they are not currently supported by ICU and
342 // they were provided by the old TEC encoding path. Needed to fix <rdar://problem/4708689>.
fallbackForGBK(UChar32 character)343 static UChar fallbackForGBK(UChar32 character)
344 {
345     switch (character) {
346     case 0x01F9:
347         return 0xE7C8;
348     case 0x1E3F:
349         return 0xE7C7;
350     case 0x22EF:
351         return 0x2026;
352     case 0x301C:
353         return 0xFF5E;
354     }
355     return 0;
356 }
357 
358 // Invalid character handler when writing escaped entities for unrepresentable
359 // characters. See the declaration of TextCodec::encode for more.
urlEscapedEntityCallback(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)360 static void urlEscapedEntityCallback(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
361     UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
362 {
363     if (reason == UCNV_UNASSIGNED) {
364         *err = U_ZERO_ERROR;
365 
366         UnencodableReplacementArray entity;
367         int entityLen = TextCodec::getUnencodableReplacement(codePoint, URLEncodedEntitiesForUnencodables, entity);
368         ucnv_cbFromUWriteBytes(fromUArgs, entity, entityLen, 0, err);
369     } else
370         UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
371 }
372 
373 // Substitutes special GBK characters, escaping all other unassigned entities.
gbkCallbackEscape(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)374 static void gbkCallbackEscape(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
375     UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
376 {
377     UChar outChar;
378     if (reason == UCNV_UNASSIGNED && (outChar = fallbackForGBK(codePoint))) {
379         const UChar* source = &outChar;
380         *err = U_ZERO_ERROR;
381         ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
382         return;
383     }
384     UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
385 }
386 
387 // Combines both gbkUrlEscapedEntityCallback and GBK character substitution.
gbkUrlEscapedEntityCallack(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)388 static void gbkUrlEscapedEntityCallack(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
389     UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
390 {
391     if (reason == UCNV_UNASSIGNED) {
392         if (UChar outChar = fallbackForGBK(codePoint)) {
393             const UChar* source = &outChar;
394             *err = U_ZERO_ERROR;
395             ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
396             return;
397         }
398         urlEscapedEntityCallback(context, fromUArgs, codeUnits, length, codePoint, reason, err);
399         return;
400     }
401     UCNV_FROM_U_CALLBACK_ESCAPE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
402 }
403 
gbkCallbackSubstitute(const void * context,UConverterFromUnicodeArgs * fromUArgs,const UChar * codeUnits,int32_t length,UChar32 codePoint,UConverterCallbackReason reason,UErrorCode * err)404 static void gbkCallbackSubstitute(const void* context, UConverterFromUnicodeArgs* fromUArgs, const UChar* codeUnits, int32_t length,
405     UChar32 codePoint, UConverterCallbackReason reason, UErrorCode* err)
406 {
407     UChar outChar;
408     if (reason == UCNV_UNASSIGNED && (outChar = fallbackForGBK(codePoint))) {
409         const UChar* source = &outChar;
410         *err = U_ZERO_ERROR;
411         ucnv_cbFromUWriteUChars(fromUArgs, &source, source + 1, 0, err);
412         return;
413     }
414     UCNV_FROM_U_CALLBACK_SUBSTITUTE(context, fromUArgs, codeUnits, length, codePoint, reason, err);
415 }
416 
encode(const UChar * characters,size_t length,UnencodableHandling handling)417 CString TextCodecICU::encode(const UChar* characters, size_t length, UnencodableHandling handling)
418 {
419     if (!length)
420         return "";
421 
422     if (!m_converterICU)
423         createICUConverter();
424     if (!m_converterICU)
425         return CString();
426 
427     // FIXME: We should see if there is "force ASCII range" mode in ICU;
428     // until then, we change the backslash into a yen sign.
429     // Encoding will change the yen sign back into a backslash.
430     String copy(characters, length);
431     copy = m_encoding.displayString(copy.impl());
432 
433     const UChar* source = copy.characters();
434     const UChar* sourceLimit = source + copy.length();
435 
436     UErrorCode err = U_ZERO_ERROR;
437 
438     switch (handling) {
439         case QuestionMarksForUnencodables:
440             ucnv_setSubstChars(m_converterICU, "?", 1, &err);
441             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkCallbackSubstitute : UCNV_FROM_U_CALLBACK_SUBSTITUTE, 0, 0, 0, &err);
442             break;
443         case EntitiesForUnencodables:
444             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkCallbackEscape : UCNV_FROM_U_CALLBACK_ESCAPE, UCNV_ESCAPE_XML_DEC, 0, 0, &err);
445             break;
446         case URLEncodedEntitiesForUnencodables:
447             ucnv_setFromUCallBack(m_converterICU, m_needsGBKFallbacks ? gbkUrlEscapedEntityCallack : urlEscapedEntityCallback, 0, 0, 0, &err);
448             break;
449     }
450 
451     ASSERT(U_SUCCESS(err));
452     if (U_FAILURE(err))
453         return CString();
454 
455     Vector<char> result;
456     size_t size = 0;
457     do {
458         char buffer[ConversionBufferSize];
459         char* target = buffer;
460         char* targetLimit = target + ConversionBufferSize;
461         err = U_ZERO_ERROR;
462         ucnv_fromUnicode(m_converterICU, &target, targetLimit, &source, sourceLimit, 0, true, &err);
463         size_t count = target - buffer;
464         result.grow(size + count);
465         memcpy(result.data() + size, buffer, count);
466         size += count;
467     } while (err == U_BUFFER_OVERFLOW_ERROR);
468 
469     return CString(result.data(), size);
470 }
471 
472 } // namespace WebCore
473