The Tor Browser: dom/encoding/FallbackEncoding.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* This Source Code Form is subject to the terms of the Mozilla Public

     2  * License, v. 2.0. If a copy of the MPL was not distributed with this

     3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 #include "mozilla/dom/FallbackEncoding.h"

     7 #include "mozilla/dom/EncodingUtils.h"

     8 #include "nsUConvPropertySearch.h"

     9 #include "nsIChromeRegistry.h"

    10 #include "mozilla/Preferences.h"

    11 #include "mozilla/Services.h"

    13 namespace mozilla {

    14 namespace dom {

    16 static const char* localesFallbacks[][3] = {

    17 #include "localesfallbacks.properties.h"

    18 };

    20 static const char* domainsFallbacks[][3] = {

    21 #include "domainsfallbacks.properties.h"

    22 };

    24 static const char* nonParticipatingDomains[][3] = {

    25 #include "nonparticipatingdomains.properties.h"

    26 };

    28 FallbackEncoding* FallbackEncoding::sInstance = nullptr;

    29 bool FallbackEncoding::sGuessFallbackFromTopLevelDomain = true;

    31 FallbackEncoding::FallbackEncoding()

    32 {

    33   MOZ_COUNT_CTOR(FallbackEncoding);

    34   MOZ_ASSERT(!FallbackEncoding::sInstance,

    35              "Singleton already exists.");

    36 }

    38 FallbackEncoding::~FallbackEncoding()

    39 {

    40   MOZ_COUNT_DTOR(FallbackEncoding);

    41 }

    43 void

    44 FallbackEncoding::Get(nsACString& aFallback)

    45 {

    46   if (!mFallback.IsEmpty()) {

    47     aFallback = mFallback;

    48     return;

    49   }

    51   const nsAdoptingCString& override =

    52     Preferences::GetCString("intl.charset.fallback.override");

    53   // Don't let the user break things by setting the override to unreasonable

    54   // values via about:config

    55   if (!EncodingUtils::FindEncodingForLabel(override, mFallback) ||

    56       !EncodingUtils::IsAsciiCompatible(mFallback) ||

    57       mFallback.EqualsLiteral("UTF-8")) {

    58     mFallback.Truncate();

    59   }

    61   if (!mFallback.IsEmpty()) {

    62     aFallback = mFallback;

    63     return;

    64   }

    66   nsAutoCString locale;

    67   nsCOMPtr<nsIXULChromeRegistry> registry =

    68     mozilla::services::GetXULChromeRegistryService();

    69   if (registry) {

    70     registry->GetSelectedLocale(NS_LITERAL_CSTRING("global"), locale);

    71   }

    73   // Let's lower case the string just in case unofficial language packs

    74   // don't stick to conventions.

    75   ToLowerCase(locale); // ASCII lowercasing with CString input!

    77   // Special case Traditional Chinese before throwing away stuff after the

    78   // language itself. Today we only ship zh-TW, but be defensive about

    79   // possible future values.

    80   if (locale.EqualsLiteral("zh-tw") ||

    81       locale.EqualsLiteral("zh-hk") ||

    82       locale.EqualsLiteral("zh-mo") ||

    83       locale.EqualsLiteral("zh-hant")) {

    84     mFallback.AssignLiteral("Big5");

    85     aFallback = mFallback;

    86     return;

    87   }

    89   // Throw away regions and other variants to accommodate weird stuff seen

    90   // in telemetry--apparently unofficial language packs.

    91   int32_t index = locale.FindChar('-');

    92   if (index >= 0) {

    93     locale.Truncate(index);

    94   }

    96   if (NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(

    97       localesFallbacks, ArrayLength(localesFallbacks), locale, mFallback))) {

    98     mFallback.AssignLiteral("windows-1252");

    99   }

   101   aFallback = mFallback;

   102 }

   104 void

   105 FallbackEncoding::FromLocale(nsACString& aFallback)

   106 {

   107   MOZ_ASSERT(FallbackEncoding::sInstance,

   108              "Using uninitialized fallback cache.");

   109   FallbackEncoding::sInstance->Get(aFallback);

   110 }

   112 // PrefChangedFunc

   113 void

   114 FallbackEncoding::PrefChanged(const char*, void*)

   115 {

   116   MOZ_ASSERT(FallbackEncoding::sInstance,

   117              "Pref callback called with null fallback cache.");

   118   FallbackEncoding::sInstance->Invalidate();

   119 }

   121 void

   122 FallbackEncoding::Initialize()

   123 {

   124   MOZ_ASSERT(!FallbackEncoding::sInstance,

   125              "Initializing pre-existing fallback cache.");

   126   FallbackEncoding::sInstance = new FallbackEncoding;

   127   Preferences::RegisterCallback(FallbackEncoding::PrefChanged,

   128                                 "intl.charset.fallback.override",

   129                                 nullptr);

   130   Preferences::RegisterCallback(FallbackEncoding::PrefChanged,

   131                                 "general.useragent.locale",

   132                                 nullptr);

   133   Preferences::AddBoolVarCache(&sGuessFallbackFromTopLevelDomain,

   134                                "intl.charset.fallback.tld");

   135 }

   137 void

   138 FallbackEncoding::Shutdown()

   139 {

   140   MOZ_ASSERT(FallbackEncoding::sInstance,

   141              "Releasing non-existent fallback cache.");

   142   delete FallbackEncoding::sInstance;

   143   FallbackEncoding::sInstance = nullptr;

   144 }

   146 bool

   147 FallbackEncoding::IsParticipatingTopLevelDomain(const nsACString& aTLD)

   148 {

   149   nsAutoCString dummy;

   150   return NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(

   151       nonParticipatingDomains,

   152       ArrayLength(nonParticipatingDomains),

   153       aTLD,

   154       dummy));

   155 }

   157 void

   158 FallbackEncoding::FromTopLevelDomain(const nsACString& aTLD,

   159                                      nsACString& aFallback)

   160 {

   161   if (NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(

   162       domainsFallbacks, ArrayLength(domainsFallbacks), aTLD, aFallback))) {

   163     aFallback.AssignLiteral("windows-1252");

   164   }

   165 }

   167 } // namespace dom

   168 } // namespace mozilla

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