Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

25 files changed, 1601 insertions, 0 deletions

diff --git a/comm/mailnews/intl/charsetData.properties b/comm/mailnews/intl/charsetData.properties
new file mode 100644
index 0000000000..d4a4147cda
--- /dev/null
+++ b/comm/mailnews/intl/charsetData.properties
@@ -0,0 +1,104 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+## Rule of this file:
+## 1. key should always be in lower case ascii so we can do case insensitive
+##    comparison in the code faster.
+
+## Format of this file:
+##
+## charset_name.isInternal = anything - specifies that this charset should
+## not be exposed to web content because of the vulnerability to XSS attacks
+## or some other reasons
+##
+## charset_name.LangGroup =
+##
+## charset_name.isMultibyte = multi byte charsets
+
+replacement.isInternal                  = true
+
+# XXX : todo: move to something based on BCP 47 (RFC 5646);
+# these should primarily specify script (and sometimes region),
+# but NOT language.
+# See also https://bugzilla.mozilla.org/show_bug.cgi?id=756022
+# e.g. x-western      -> *-Latn-155 (Western Europe),
+#                        *-Latn-151 (Eastern Europe),
+#                        *-Latn-154 (Northern Europe),
+#                        *-Latn-TR
+#      x-cyrillic     -> *-Cyrl
+#      zh-TW          -> *-Hant-TW
+#      zh-HK          -> *-Hant-HK
+#      zh-CN          -> *-Hans
+#      ja             -> *-Jpan
+#      ko             -> *-Hang
+#      he             -> *-Hebr
+#      ar             -> *-Arab
+# etc
+
+big5.LangGroup                     = zh-TW
+big5-hkscs.LangGroup               = zh-HK
+euc-jp.LangGroup                   = ja
+euc-kr.LangGroup                   = ko
+gb2312.LangGroup                   = zh-CN
+gb18030.LangGroup                  = zh-CN
+gb18030.2000-0.LangGroup           = zh-CN
+gb18030.2000-1.LangGroup           = zh-CN
+hkscs-1.LangGroup                  = zh-HK
+ibm866.LangGroup                   = x-cyrillic
+ibm1125.LangGroup                  = x-cyrillic
+ibm1131.LangGroup                  = x-cyrillic
+iso-2022-jp.LangGroup              = ja
+iso-8859-1.LangGroup               = x-western
+iso-8859-10.LangGroup              = x-western
+iso-8859-14.LangGroup              = x-western
+iso-8859-15.LangGroup              = x-western
+iso-8859-2.LangGroup               = x-western
+iso-8859-16.LangGroup              = x-western
+iso-8859-3.LangGroup               = x-western
+iso-8859-4.LangGroup               = x-western
+iso-8859-13.LangGroup              = x-western
+iso-8859-5.LangGroup               = x-cyrillic
+iso-8859-6.LangGroup               = ar
+iso-8859-7.LangGroup               = el
+iso-8859-8.LangGroup               = he
+iso-8859-8-i.LangGroup             = he
+jis_0208-1983.LangGroup            = ja
+koi8-r.LangGroup                   = x-cyrillic
+koi8-u.LangGroup                   = x-cyrillic
+shift_jis.LangGroup                = ja
+windows-874.LangGroup              = th
+utf-8.LangGroup                    = x-unicode
+utf-16.LangGroup                   = x-unicode
+utf-16be.LangGroup                 = x-unicode
+utf-16le.LangGroup                 = x-unicode
+utf-7.LangGroup                    = x-unicode
+replacement.LangGroup              = x-unicode
+windows-1250.LangGroup             = x-western
+windows-1251.LangGroup             = x-cyrillic
+windows-1252.LangGroup             = x-western
+windows-1253.LangGroup             = el
+windows-1254.LangGroup             = x-western
+windows-1255.LangGroup             = he
+windows-1256.LangGroup             = ar
+windows-1257.LangGroup             = x-western
+windows-1258.LangGroup             = x-western
+gbk.LangGroup                      = zh-CN
+
+# The following two are in the Encoding Standard (https://encoding.spec.whatwg.org/),
+# x-mac-ukrainian is a label.
+x-mac-cyrillic.LangGroup           = x-cyrillic
+macintosh.LangGroup                = x-western
+
+x-user-defined.LangGroup           = x-unicode
+
+iso-2022-jp.isMultibyte     = true
+shift_jis.isMultibyte       = true
+euc-jp.isMultibyte          = true
+big5.isMultibyte            = true
+big5-hkscs.isMultibyte      = true
+gb2312.isMultibyte          = true
+euc-kr.isMultibyte          = true
+utf-7.isMultibyte           = true
+utf-8.isMultibyte           = true
+replacement.isMultibyte     = true
diff --git a/comm/mailnews/intl/charsetalias.properties b/comm/mailnews/intl/charsetalias.properties
new file mode 100644
index 0000000000..1ef5e52ee2
--- /dev/null
+++ b/comm/mailnews/intl/charsetalias.properties
@@ -0,0 +1,151 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Rule of this file:
+# 1. key should always be in lower case ascii so we can do case insensitive
+#    comparison in the code faster.
+# 2. value should be the _name_ used in the WHATWG Encoding Standard
+#    https://encoding.spec.whatwg.org/ (of "UTF-7" for UTF-7).
+#
+# This file contains email-specific labels. Web-relevant labels for
+# encodings are in the Encoding Standard / encoding_rs.
+
+# Added for Solaris ns_langinfo. Unlikely relevant to email.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=77300#c9
+646=windows-1252
+
+# Aliases for ISO-8859-8-I
+# From the original IBM bidi patch.
+iso-8859-8i=ISO-8859-8-I
+
+# ISO 8859 series with underscore for JavaMail
+# compat.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=820767
+iso8859_1=windows-1252
+iso8859_2=ISO-8859-2
+iso8859_3=ISO-8859-3
+iso8859_4=ISO-8859-4
+iso8859_5=ISO-8859-5
+iso8859_6=ISO-8859-6
+iso8859_7=ISO-8859-7
+# Unclear if 8 with underscore was visual or not
+iso8859_9=windows-1254
+# No evidence of 10 occurring with underscore
+# 11 is tis620
+# 12 does not exist
+iso8859_13=ISO-8859-13
+# No evidence of 14 occurring with underscore
+iso8859_15=ISO-8859-15
+# No evidence of 16 occurring with underscore
+
+koi8r=KOI8-R
+
+# Code pages shared by DOS and Windows with ms prefix.
+# Evidence of this pattern in the wild:
+# https://bugzilla.mozilla.org/show_bug.cgi?id=1120813
+# Plausible cause: JavaMail
+# The ms prefix as used by Sun is not relevant to windows-125x series
+ms874=windows-874
+# ms932 was added to the Encoding Standard as one-off Thunderbird request
+# MS936 shows up at https://www.iana.org/assignments/character-sets/character-sets.xhtml
+ms936=GBK
+ms949=EUC-KR
+ms950=Big5
+ms950_hkscs=Big5
+
+# Underscore versions of Unix CJK encodings.
+# No evidence of these in the wild, but these could plausibly
+# occur for the same reason as the above two groups.
+euc_cn=GBK
+euc_kr=EUC-KR
+euc_jp=EUC-JP
+big5_hkscs=Big5
+
+# Code pages shared by DOS and Windows with cp prefix
+# cp125x series are in the Encoding Standard
+# Evidence of the pattern in the wild:
+# https://bugzilla.mozilla.org/show_bug.cgi?id=1511950
+# https://bugzilla.mozilla.org/show_bug.cgi?id=542823
+# https://bugzilla.mozilla.org/show_bug.cgi?id=1217161
+cp874=windows-874
+cp932=Shift_JIS
+# CP936 shows up at https://www.iana.org/assignments/character-sets/character-sets.xhtml
+cp936=GBK
+cp949=EUC-KR
+cp950=Big5
+
+# Aliases for ISO-2022-JP
+# The following are really not aliases ISO-2022-JP, but sharing the same decoder
+# Kept mainly for compat with old Apple Mail.
+iso-2022-jp-2=ISO-2022-JP
+csiso2022jp2=ISO-2022-JP
+# A Google search suggests the variant without hyphens has been used with
+# JavaMail.
+iso2022jp=ISO-2022-JP
+
+# Aliases for Big5
+# Added in patch that generally meant to support emails sent by
+# dtmail on Sun Solaris
+# https://bugzilla.mozilla.org/show_bug.cgi?id=146287
+zh_tw-big5=Big5
+
+# Aliases for EUC-KR
+# Added for Solaris ns_langinfo. Unlikely relevant to email.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=82075
+5601=EUC-KR
+# https://bugzilla.mozilla.org/show_bug.cgi?id=234958
+x-windows-949=EUC-KR
+
+# Aliases for windows-874
+# Added originally for nl_langinfo reasons but could plausibly be sent
+# by JavaMail.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=101295
+tis620=windows-874
+
+# Aliases for IBM866
+# This alias may have been made up by accident and may
+# not be relevant to real-world email.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=77588
+cp-866=IBM866
+
+# Aliases for UTF-7
+utf-7=UTF-7
+# The below 4 aliases were not in Thunderbird 60, and there were
+# no complaints.
+# This alias appears to have been generated by the email part
+# of the Netscape 4.0 suite per http://jkorpela.fi/chars.html
+x-unicode-2-0-utf-7=UTF-7
+# This appears to be just a made-up non-x version of the above
+# (checked in without bug number).
+unicode-2-0-utf-7=UTF-7
+# The two aliases below show up at
+# https://www.iana.org/assignments/character-sets/character-sets.xhtml
+unicode-1-1-utf-7=UTF-7
+csunicode11utf7=UTF-7
+
+# The below aliases were not in Thunderbird 60, and there were
+# no complaints.
+# These aliases show up at
+# https://www.iana.org/assignments/character-sets/character-sets.xhtml
+csunicode=UTF-16BE
+csunicode11=UTF-16BE
+iso-10646-ucs-basic=UTF-16BE
+csunicodeascii=UTF-16BE
+iso-10646-unicode-latin1=UTF-16BE
+csunicodelatin1=UTF-16BE
+iso-10646=UTF-16BE
+iso-10646-j-1=UTF-16BE
+iso-10646-ucs-2=UTF-16BE
+# Netscape aliases checked in without bug number.
+# Possibly meant to be Netscape-private.
+x-iso-10646-ucs-2-be=UTF-16BE
+x-iso-10646-ucs-2-le=UTF-16LE
+
+# Shows up at https://www.iana.org/assignments/character-sets/character-sets.xhtml
+# https://bugzilla.mozilla.org/show_bug.cgi?id=651113
+windows-936=GBK
+
+# Added for Solaris ns_langinfo(). Unlikely to be relevant to email.
+# https://bugzilla.mozilla.org/show_bug.cgi?id=82075
+ansi-1251=windows-1251
diff --git a/comm/mailnews/intl/components.conf b/comm/mailnews/intl/components.conf
new file mode 100644
index 0000000000..6c1f128442
--- /dev/null
+++ b/comm/mailnews/intl/components.conf
@@ -0,0 +1,12 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        "cid": "{3c1c0163-9bd0-11d3-9d09-0050040007b2}",
+        "contract_ids": ["@mozilla.org/charset-converter-manager;1"],
+        "type": "nsCharsetConverterManager",
+        "headers": ["/comm/mailnews/intl/nsCharsetConverterManager.h"],
+    },
+]
diff --git a/comm/mailnews/intl/jar.mn b/comm/mailnews/intl/jar.mn
new file mode 100644
index 0000000000..ab02275d97
--- /dev/null
+++ b/comm/mailnews/intl/jar.mn
@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+toolkit.jar:
+    res/charsetData.properties                         (charsetData.properties)
diff --git a/comm/mailnews/intl/moz.build b/comm/mailnews/intl/moz.build
new file mode 100644
index 0000000000..03b8a13a46
--- /dev/null
+++ b/comm/mailnews/intl/moz.build
@@ -0,0 +1,42 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    "nsICharsetConverterManager.idl",
+]
+
+UNIFIED_SOURCES += [
+    "nsCharsetAlias.cpp",
+    "nsCharsetConverterManager.cpp",
+    "nsMUTF7ToUnicode.cpp",
+    "nsUnicodeToMUTF7.cpp",
+    "nsUnicodeToUTF7.cpp",
+    "nsUTF7ToUnicode.cpp",
+]
+
+XPIDL_MODULE = "commuconv"
+
+LOCAL_INCLUDES += [
+    "/intl/locale",
+]
+
+GENERATED_FILES += [
+    "charsetalias.properties.h",
+]
+charsetalias = GENERATED_FILES["charsetalias.properties.h"]
+charsetalias.script = "/intl/locale/props2arrays.py"
+charsetalias.inputs = ["charsetalias.properties"]
+
+FINAL_LIBRARY = "mail"
+
+# Tests need more attention before they can be enabled.
+TEST_DIRS += ["test"]
+
+JAR_MANIFESTS += ["jar.mn"]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
diff --git a/comm/mailnews/intl/nsCharsetAlias.cpp b/comm/mailnews/intl/nsCharsetAlias.cpp
new file mode 100644
index 0000000000..a92cf193c9
--- /dev/null
+++ b/comm/mailnews/intl/nsCharsetAlias.cpp
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Encoding.h"
+
+#include "nsCharsetAlias.h"
+
+// for NS_ERROR_UCONV_NOCONV
+#include "nsCharsetConverterManager.h"
+
+#include "nsUConvPropertySearch.h"
+
+using namespace mozilla;
+
+//
+static const nsUConvProp kAliases[] = {
+#include "charsetalias.properties.h"
+};
+
+//--------------------------------------------------------------
+// static
+nsresult nsCharsetAlias::GetPreferredInternal(const nsACString& aAlias,
+                                              nsACString& oResult) {
+  // First check charsetalias.properties and if there is no match, continue to
+  // call Encoding::ForLabel.
+  nsAutoCString key(aAlias);
+  ToLowerCase(key);
+
+  nsresult rv = nsUConvPropertySearch::SearchPropertyValue(
+      kAliases, ArrayLength(kAliases), key, oResult);
+  if (NS_SUCCEEDED(rv)) {
+    return NS_OK;
+  }
+
+  const Encoding* encoding = Encoding::ForLabel(key);
+  if (!encoding) return NS_ERROR_NOT_AVAILABLE;
+  encoding->Name(oResult);
+  return NS_OK;
+}
+
+//--------------------------------------------------------------
+// static
+nsresult nsCharsetAlias::GetPreferred(const nsACString& aAlias,
+                                      nsACString& oResult) {
+  if (aAlias.IsEmpty()) return NS_ERROR_NULL_POINTER;
+
+  nsresult res = GetPreferredInternal(aAlias, oResult);
+  if (NS_FAILED(res)) return res;
+
+  if (nsCharsetConverterManager::IsInternal(oResult))
+    return NS_ERROR_UCONV_NOCONV;
+
+  return res;
+}
+
+//--------------------------------------------------------------
+// static
+nsresult nsCharsetAlias::Equals(const nsACString& aCharset1,
+                                const nsACString& aCharset2, bool* oResult) {
+  nsresult res = NS_OK;
+
+  if (aCharset1.Equals(aCharset2, nsCaseInsensitiveCStringComparator)) {
+    *oResult = true;
+    return res;
+  }
+
+  if (aCharset1.IsEmpty() || aCharset2.IsEmpty()) {
+    *oResult = false;
+    return res;
+  }
+
+  *oResult = false;
+  nsAutoCString name1;
+  res = GetPreferredInternal(aCharset1, name1);
+  if (NS_FAILED(res)) return res;
+
+  nsAutoCString name2;
+  res = GetPreferredInternal(aCharset2, name2);
+  if (NS_FAILED(res)) return res;
+
+  *oResult = name1.Equals(name2);
+  return NS_OK;
+}
diff --git a/comm/mailnews/intl/nsCharsetAlias.h b/comm/mailnews/intl/nsCharsetAlias.h
new file mode 100644
index 0000000000..6b24f33567
--- /dev/null
+++ b/comm/mailnews/intl/nsCharsetAlias.h
@@ -0,0 +1,27 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsCharsetAlias_h___
+#define nsCharsetAlias_h___
+
+#include "nscore.h"
+#include "nsString.h"
+
+class nsCharsetConverterManager;
+class nsScriptableUnicodeConverter;
+
+class nsCharsetAlias {
+  friend class nsCharsetConverterManager;
+  friend class nsScriptableUnicodeConverter;
+  static nsresult GetPreferredInternal(const nsACString& aAlias,
+                                       nsACString& aResult);
+
+ public:
+  static nsresult GetPreferred(const nsACString& aAlias, nsACString& aResult);
+  static nsresult Equals(const nsACString& aCharset1,
+                         const nsACString& aCharset2, bool* aResult);
+};
+
+#endif /* nsCharsetAlias_h___ */
diff --git a/comm/mailnews/intl/nsCharsetConverterManager.cpp b/comm/mailnews/intl/nsCharsetConverterManager.cpp
new file mode 100644
index 0000000000..a15917206e
--- /dev/null
+++ b/comm/mailnews/intl/nsCharsetConverterManager.cpp
@@ -0,0 +1,184 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsUnicharUtils.h"
+#include "nsCharsetAlias.h"
+#include "nsICharsetConverterManager.h"
+#include "nsIStringBundle.h"
+#include "nsTArray.h"
+#include "mozilla/Components.h"
+
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "../base/src/nsMsgI18N.h"
+
+// just for CONTRACTIDs
+#include "nsCharsetConverterManager.h"
+
+static nsCOMPtr<nsIStringBundle> sDataBundle;
+static nsCOMPtr<nsIStringBundle> sTitleBundle;
+
+// Class nsCharsetConverterManager [implementation]
+
+NS_IMPL_ISUPPORTS(nsCharsetConverterManager, nsICharsetConverterManager)
+
+nsCharsetConverterManager::nsCharsetConverterManager() {}
+
+nsCharsetConverterManager::~nsCharsetConverterManager() {
+  sDataBundle = nullptr;
+  sTitleBundle = nullptr;
+}
+
+static nsresult LoadBundle(const char* aBundleURLSpec,
+                           nsIStringBundle** aResult) {
+  nsCOMPtr<nsIStringBundleService> sbServ =
+      mozilla::components::StringBundle::Service();
+  if (!sbServ) return NS_ERROR_FAILURE;
+
+  return sbServ->CreateBundle(aBundleURLSpec, aResult);
+}
+
+static nsresult GetBundleValueInner(nsIStringBundle* aBundle, const char* aName,
+                                    const nsString& aProp, nsAString& aResult) {
+  nsAutoString key;
+
+  CopyASCIItoUTF16(mozilla::MakeStringSpan(aName), key);
+  ToLowerCase(key);  // we lowercase the main comparison key
+  key.Append(aProp);
+
+  return aBundle->GetStringFromName(NS_ConvertUTF16toUTF8(key).get(), aResult);
+}
+
+static nsresult GetBundleValue(nsIStringBundle* aBundle, const char* aName,
+                               const nsString& aProp, nsAString& aResult) {
+  nsresult rv = NS_OK;
+
+  nsAutoString value;
+  rv = GetBundleValueInner(aBundle, aName, aProp, value);
+  if (NS_FAILED(rv)) return rv;
+
+  aResult = value;
+
+  return NS_OK;
+}
+
+static nsresult GetCharsetDataImpl(const char* aCharset, const char16_t* aProp,
+                                   nsAString& aResult) {
+  NS_ENSURE_ARG_POINTER(aCharset);
+  // aProp can be nullptr
+
+  if (!sDataBundle) {
+    nsresult rv = LoadBundle("resource://gre-resources/charsetData.properties",
+                             getter_AddRefs(sDataBundle));
+    if (NS_FAILED(rv)) return rv;
+  }
+
+  return GetBundleValue(sDataBundle, aCharset, nsDependentString(aProp),
+                        aResult);
+}
+
+// static
+bool nsCharsetConverterManager::IsInternal(const nsACString& aCharset) {
+  nsAutoString str;
+  // fully qualify to possibly avoid vtable call
+  nsresult rv = GetCharsetDataImpl(PromiseFlatCString(aCharset).get(),
+                                   u".isInternal", str);
+
+  return NS_SUCCEEDED(rv);
+}
+
+//----------------------------------------------------------------------------//----------------------------------------------------------------------------
+// Interface nsICharsetConverterManager [implementation]
+
+// XXX Improve the implementation of this method. Right now, it is build on
+// top of the nsCharsetAlias service. We can make the nsCharsetAlias
+// better, with its own hash table (not the StringBundle anymore) and
+// a nicer file format.
+NS_IMETHODIMP
+nsCharsetConverterManager::GetCharsetAlias(const char* aCharset,
+                                           nsACString& aResult) {
+  NS_ENSURE_ARG_POINTER(aCharset);
+
+  // We try to obtain the preferred name for this charset from the charset
+  // aliases.
+  nsresult rv;
+
+  rv = nsCharsetAlias::GetPreferred(nsDependentCString(aCharset), aResult);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::GetCharsetTitle(const char* aCharset,
+                                           nsAString& aResult) {
+  NS_ENSURE_ARG_POINTER(aCharset);
+
+  if (!sTitleBundle) {
+    nsresult rv =
+        LoadBundle("chrome://messenger/locale/charsetTitles.properties",
+                   getter_AddRefs(sTitleBundle));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return GetBundleValue(sTitleBundle, aCharset, u".title"_ns, aResult);
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::GetCharsetData(const char* aCharset,
+                                          const char16_t* aProp,
+                                          nsAString& aResult) {
+  return GetCharsetDataImpl(aCharset, aProp, aResult);
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::GetCharsetLangGroup(const char* aCharset,
+                                               nsACString& aResult) {
+  // resolve the charset first
+  nsAutoCString charset;
+
+  nsresult rv = GetCharsetAlias(aCharset, charset);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // fully qualify to possibly avoid vtable call
+  return nsCharsetConverterManager::GetCharsetLangGroupRaw(charset.get(),
+                                                           aResult);
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::GetCharsetLangGroupRaw(const char* aCharset,
+                                                  nsACString& aResult) {
+  nsAutoString langGroup;
+  // fully qualify to possibly avoid vtable call
+  nsresult rv = nsCharsetConverterManager::GetCharsetData(
+      aCharset, u".LangGroup", langGroup);
+
+  if (NS_SUCCEEDED(rv)) {
+    ToLowerCase(langGroup);  // use lowercase for all language groups
+    aResult = NS_ConvertUTF16toUTF8(langGroup);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::Utf7ToUnicode(const nsACString& aSrc,
+                                         nsAString& aDest) {
+  return CopyUTF7toUTF16(aSrc, aDest);
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::Mutf7ToUnicode(const nsACString& aSrc,
+                                          nsAString& aDest) {
+  return CopyMUTF7toUTF16(aSrc, aDest);
+}
+
+NS_IMETHODIMP
+nsCharsetConverterManager::UnicodeToMutf7(const nsAString& aSrc,
+                                          nsACString& aDest) {
+  return CopyUTF16toMUTF7(aSrc, aDest);
+}
diff --git a/comm/mailnews/intl/nsCharsetConverterManager.h b/comm/mailnews/intl/nsCharsetConverterManager.h
new file mode 100644
index 0000000000..9a217bf0e6
--- /dev/null
+++ b/comm/mailnews/intl/nsCharsetConverterManager.h
@@ -0,0 +1,27 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef nsCharsetConverterManager_h__
+#define nsCharsetConverterManager_h__
+
+#include "nsICharsetConverterManager.h"
+
+class nsCharsetAlias;
+
+class nsCharsetConverterManager : public nsICharsetConverterManager {
+  friend class nsCharsetAlias;
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSICHARSETCONVERTERMANAGER
+
+ public:
+  nsCharsetConverterManager();
+
+ private:
+  virtual ~nsCharsetConverterManager();
+
+  static bool IsInternal(const nsACString& aCharset);
+};
+
+#endif  // nsCharsetConverterManager_h__
diff --git a/comm/mailnews/intl/nsICharsetConverterManager.idl b/comm/mailnews/intl/nsICharsetConverterManager.idl
new file mode 100644
index 0000000000..fe77ed6843
--- /dev/null
+++ b/comm/mailnews/intl/nsICharsetConverterManager.idl
@@ -0,0 +1,71 @@
+/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+%{C++
+#include "mozilla/Encoding.h"
+
+// XXX change to NS_CHARSETCONVERTERMANAGER_CID
+#define NS_ICHARSETCONVERTERMANAGER_CID \
+  {0x3c1c0163, 0x9bd0, 0x11d3, { 0x9d, 0x9, 0x0, 0x50, 0x4, 0x0, 0x7, 0xb2}}
+
+#define NS_CHARSETCONVERTERMANAGER_CONTRACTID "@mozilla.org/charset-converter-manager;1"
+%}
+
+[scriptable, uuid(a0550d46-8d9c-47dd-acc7-c083620dff12)]
+interface nsICharsetConverterManager : nsISupports
+{
+    /**
+     * A shortcut to calling nsICharsetAlias to do alias resolution
+     * @throws if aCharset is an unknown charset.
+     */
+    ACString getCharsetAlias(in string aCharset);
+
+    /**
+     * Get the human-readable name for the given charset.
+     * @throws if aCharset is an unknown charset.
+     */
+    AString getCharsetTitle(in string aCharset);
+
+    /**
+     * Get some data about the given charset. This includes whether the
+     * character encoding may be used for certain purposes, if it is
+     * multi-byte, and the language code for it. See charsetData.properties
+     * for the source of this data. Some known property names:
+     *    LangGroup      - language code for charset, e.g. 'he' and 'zh-CN'.
+     *    isMultibyte    - is this a multi-byte charset?
+     *    isInternal     - not to be used in untrusted web content.
+     *
+     * @param aCharset name of the character encoding, e.g. 'iso-8859-15'.
+     * @param aProp property desired for the character encoding.
+     * @throws if aCharset is an unknown charset.
+     * @return the value of the property, for the character encoding.
+     */
+    AString getCharsetData(in string aCharset,
+                           in wstring aProp);
+
+    /**
+     * Get the language group for the given charset. This is similar to
+     * calling <tt>getCharsetData</tt> with the <tt>prop</tt> "LangGroup".
+     *
+     * @param aCharset name of the character encoding, e.g. 'iso-8859-15'.
+     * @throws if aCharset is an unknown charset.
+     * @return the language code for the character encoding.
+     */
+    AUTF8String getCharsetLangGroup(in string aCharset);
+    AUTF8String getCharsetLangGroupRaw(in string aCharset);
+
+    /**
+     * Decoding of UTF-7 in message headers and bodies.
+     */
+    AString utf7ToUnicode(in ACString aMutf7);
+
+    /**
+     * Support for Modified UTF-7 (MUTF-7) used by IMAP.
+     */
+    AString mutf7ToUnicode(in ACString aMutf7);
+    ACString unicodeToMutf7(in AString aUnicode);
+};
diff --git a/comm/mailnews/intl/nsMUTF7ToUnicode.cpp b/comm/mailnews/intl/nsMUTF7ToUnicode.cpp
new file mode 100644
index 0000000000..bd49d647fa
--- /dev/null
+++ b/comm/mailnews/intl/nsMUTF7ToUnicode.cpp
@@ -0,0 +1,11 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsMUTF7ToUnicode.h"
+
+//----------------------------------------------------------------------
+// Class nsMUTF7ToUnicode [implementation]
+
+nsMUTF7ToUnicode::nsMUTF7ToUnicode() : nsBasicUTF7Decoder(',', '&') {}
diff --git a/comm/mailnews/intl/nsMUTF7ToUnicode.h b/comm/mailnews/intl/nsMUTF7ToUnicode.h
new file mode 100644
index 0000000000..ff26e8b6ab
--- /dev/null
+++ b/comm/mailnews/intl/nsMUTF7ToUnicode.h
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsMUTF7ToUnicode_h___
+#define nsMUTF7ToUnicode_h___
+
+#include "nsUTF7ToUnicode.h"
+
+//----------------------------------------------------------------------
+// Class nsMUTF7ToUnicode [declaration]
+
+/**
+ * A character set converter from Modified UTF7 to Unicode.
+ *
+ * @created         18/May/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsMUTF7ToUnicode : public nsBasicUTF7Decoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsMUTF7ToUnicode();
+};
+
+#endif /* nsMUTF7ToUnicode_h___ */
diff --git a/comm/mailnews/intl/nsUTF7ToUnicode.cpp b/comm/mailnews/intl/nsUTF7ToUnicode.cpp
new file mode 100644
index 0000000000..2257affa51
--- /dev/null
+++ b/comm/mailnews/intl/nsUTF7ToUnicode.cpp
@@ -0,0 +1,217 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsUTF7ToUnicode.h"
+
+#define ENC_DIRECT 0
+#define ENC_BASE64 1
+
+//----------------------------------------------------------------------
+// Class nsBasicUTF7Decoder [implementation]
+
+nsBasicUTF7Decoder::nsBasicUTF7Decoder(char aLastChar, char aEscChar) {
+  mLastChar = aLastChar;
+  mEscChar = aEscChar;
+  mFreshBase64 = false;
+  Reset();
+}
+
+nsresult nsBasicUTF7Decoder::DecodeDirect(const char* aSrc, int32_t* aSrcLength,
+                                          char16_t* aDest,
+                                          int32_t* aDestLength) {
+  const char* srcEnd = aSrc + *aSrcLength;
+  const char* src = aSrc;
+  char16_t* destEnd = aDest + *aDestLength;
+  char16_t* dest = aDest;
+  nsresult res = NS_OK;
+  char ch;
+
+  while (src < srcEnd) {
+    ch = *src;
+
+    // stop when we meet other chars or end of direct encoded seq.
+    // if (!(DirectEncodable(ch)) || (ch == mEscChar)) {
+    // but we are decoding; so we should be lax; pass everything until escchar
+    if (ch == mEscChar) {
+      res = NS_ERROR_UDEC_ILLEGALINPUT;
+      break;
+    }
+
+    if (dest >= destEnd) {
+      res = NS_OK_UDEC_MOREOUTPUT;
+      break;
+    } else {
+      *dest++ = ch;
+      src++;
+    }
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+nsresult nsBasicUTF7Decoder::DecodeBase64(const char* aSrc, int32_t* aSrcLength,
+                                          char16_t* aDest,
+                                          int32_t* aDestLength) {
+  const char* srcEnd = aSrc + *aSrcLength;
+  const char* src = aSrc;
+  char16_t* destEnd = aDest + *aDestLength;
+  char16_t* dest = aDest;
+  nsresult res = NS_OK;
+  char ch;
+  uint32_t value;
+
+  while (src < srcEnd) {
+    ch = *src;
+
+    // stop when we meet other chars or end of direct encoded seq.
+    value = CharToValue(ch);
+    if (value > 0xff) {
+      res = NS_ERROR_UDEC_ILLEGALINPUT;
+      break;
+    }
+
+    switch (mEncStep) {
+      case 0:
+        mEncBits = value << 10;
+        break;
+      case 1:
+        mEncBits += value << 4;
+        break;
+      case 2:
+        if (dest >= destEnd) {
+          res = NS_OK_UDEC_MOREOUTPUT;
+          break;
+        }
+        mEncBits += value >> 2;
+        *(dest++) = (char16_t)mEncBits;
+        mEncBits = (value & 0x03) << 14;
+        break;
+      case 3:
+        mEncBits += value << 8;
+        break;
+      case 4:
+        mEncBits += value << 2;
+        break;
+      case 5:
+        if (dest >= destEnd) {
+          res = NS_OK_UDEC_MOREOUTPUT;
+          break;
+        }
+        mEncBits += value >> 4;
+        *(dest++) = (char16_t)mEncBits;
+        mEncBits = (value & 0x0f) << 12;
+        break;
+      case 6:
+        mEncBits += value << 6;
+        break;
+      case 7:
+        if (dest >= destEnd) {
+          res = NS_OK_UDEC_MOREOUTPUT;
+          break;
+        }
+        mEncBits += value;
+        *(dest++) = (char16_t)mEncBits;
+        mEncBits = 0;
+        break;
+    }
+
+    if (res != NS_OK) break;
+
+    src++;
+    (++mEncStep) %= 8;
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+uint32_t nsBasicUTF7Decoder::CharToValue(char aChar) {
+  if ((aChar >= 'A') && (aChar <= 'Z'))
+    return (uint8_t)(aChar - 'A');
+  else if ((aChar >= 'a') && (aChar <= 'z'))
+    return (uint8_t)(26 + aChar - 'a');
+  else if ((aChar >= '0') && (aChar <= '9'))
+    return (uint8_t)(26 + 26 + aChar - '0');
+  else if (aChar == '+')
+    return (uint8_t)(26 + 26 + 10);
+  else if (aChar == mLastChar)
+    return (uint8_t)(26 + 26 + 10 + 1);
+  else
+    return 0xffff;
+}
+
+//----------------------------------------------------------------------
+// Subclassing of nsBufferDecoderSupport class [implementation]
+
+NS_IMETHODIMP nsBasicUTF7Decoder::ConvertNoBuff(const char* aSrc,
+                                                int32_t* aSrcLength,
+                                                char16_t* aDest,
+                                                int32_t* aDestLength) {
+  const char* srcEnd = aSrc + *aSrcLength;
+  const char* src = aSrc;
+  char16_t* destEnd = aDest + *aDestLength;
+  char16_t* dest = aDest;
+  int32_t bcr, bcw;
+  nsresult res = NS_OK;
+
+  while (src < srcEnd) {
+    // first, attempt to decode in the current mode
+    bcr = srcEnd - src;
+    bcw = destEnd - dest;
+    if (mEncoding == ENC_DIRECT)
+      res = DecodeDirect(src, &bcr, dest, &bcw);
+    else if ((mFreshBase64) && (*src == '-')) {
+      *dest = mEscChar;
+      bcr = 0;
+      bcw = 1;
+      res = NS_ERROR_UDEC_ILLEGALINPUT;
+    } else {
+      mFreshBase64 = false;
+      res = DecodeBase64(src, &bcr, dest, &bcw);
+    }
+    src += bcr;
+    dest += bcw;
+
+    // if an illegal char was encountered, test if it is an escape seq.
+    if (res == NS_ERROR_UDEC_ILLEGALINPUT) {
+      if (mEncoding == ENC_DIRECT) {
+        if (*src == mEscChar) {
+          mEncoding = ENC_BASE64;
+          mFreshBase64 = true;
+          mEncBits = 0;
+          mEncStep = 0;
+          src++;
+          res = NS_OK;
+        } else
+          break;
+      } else {
+        mEncoding = ENC_DIRECT;
+        res = NS_OK;
+        // absorbe end of escape sequence
+        if (*src == '-') src++;
+      }
+    } else if (res != NS_OK)
+      break;
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+NS_IMETHODIMP nsBasicUTF7Decoder::Reset() {
+  mEncoding = ENC_DIRECT;
+  mEncBits = 0;
+  mEncStep = 0;
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------
+// Class nsUTF7ToUnicode [implementation]
+
+nsUTF7ToUnicode::nsUTF7ToUnicode() : nsBasicUTF7Decoder('/', '+') {}
diff --git a/comm/mailnews/intl/nsUTF7ToUnicode.h b/comm/mailnews/intl/nsUTF7ToUnicode.h
new file mode 100644
index 0000000000..b7b5be4522
--- /dev/null
+++ b/comm/mailnews/intl/nsUTF7ToUnicode.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsUTF7ToUnicode_h___
+#define nsUTF7ToUnicode_h___
+
+//----------------------------------------------------------------------
+// Class nsBasicUTF7Decoder [declaration]
+
+/**
+ * Basic class for a character set converter from UTF-7 to Unicode.
+ *
+ * @created         03/Jun/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsBasicUTF7Decoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsBasicUTF7Decoder(char aLastChar, char aEscChar);
+  NS_IMETHOD ConvertNoBuff(const char* aSrc, int32_t* aSrcLength,
+                           char16_t* aDest, int32_t* aDestLength);
+
+ protected:
+  int32_t mEncoding;  // current encoding
+  uint32_t mEncBits;
+  int32_t mEncStep;
+  char mLastChar;
+  char mEscChar;
+  bool mFreshBase64;
+
+  nsresult DecodeDirect(const char* aSrc, int32_t* aSrcLength, char16_t* aDest,
+                        int32_t* aDestLength);
+  nsresult DecodeBase64(const char* aSrc, int32_t* aSrcLength, char16_t* aDest,
+                        int32_t* aDestLength);
+  uint32_t CharToValue(char aChar);
+
+  //--------------------------------------------------------------------
+  // Subclassing of nsBufferDecoderSupport class [declaration]
+
+  NS_IMETHOD Reset();
+};
+
+//----------------------------------------------------------------------
+// Class nsUTF7ToUnicode [declaration]
+
+/**
+ * A character set converter from Modified UTF7 to Unicode.
+ *
+ * @created         18/May/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsUTF7ToUnicode : public nsBasicUTF7Decoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsUTF7ToUnicode();
+};
+
+#endif /* nsUTF7ToUnicode_h___ */
diff --git a/comm/mailnews/intl/nsUnicodeToMUTF7.cpp b/comm/mailnews/intl/nsUnicodeToMUTF7.cpp
new file mode 100644
index 0000000000..56433a5421
--- /dev/null
+++ b/comm/mailnews/intl/nsUnicodeToMUTF7.cpp
@@ -0,0 +1,11 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsUnicodeToMUTF7.h"
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToMUTF7 [implementation]
+
+nsUnicodeToMUTF7::nsUnicodeToMUTF7() : nsBasicUTF7Encoder(',', '&') {}
diff --git a/comm/mailnews/intl/nsUnicodeToMUTF7.h b/comm/mailnews/intl/nsUnicodeToMUTF7.h
new file mode 100644
index 0000000000..fafb3b6a84
--- /dev/null
+++ b/comm/mailnews/intl/nsUnicodeToMUTF7.h
@@ -0,0 +1,28 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsUnicodeToMUTF7_h___
+#define nsUnicodeToMUTF7_h___
+
+#include "nsUnicodeToUTF7.h"
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToMUTF7 [declaration]
+
+/**
+ * A character set converter from Unicode to Modified UTF-7.
+ *
+ * @created         18/May/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsUnicodeToMUTF7 : public nsBasicUTF7Encoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsUnicodeToMUTF7();
+};
+
+#endif /* nsUnicodeToMUTF7_h___ */
diff --git a/comm/mailnews/intl/nsUnicodeToUTF7.cpp b/comm/mailnews/intl/nsUnicodeToUTF7.cpp
new file mode 100644
index 0000000000..ab9d1cf895
--- /dev/null
+++ b/comm/mailnews/intl/nsUnicodeToUTF7.cpp
@@ -0,0 +1,302 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsUnicodeToUTF7.h"
+#include <string.h>
+
+//----------------------------------------------------------------------
+// Global functions and data [declaration]
+
+#define ENC_DIRECT 0
+#define ENC_BASE64 1
+
+//----------------------------------------------------------------------
+// Class nsBasicUTF7Encoder [implementation]
+
+nsBasicUTF7Encoder::nsBasicUTF7Encoder(char aLastChar, char aEscChar) {
+  mLastChar = aLastChar;
+  mEscChar = aEscChar;
+  Reset();
+}
+
+nsresult nsBasicUTF7Encoder::ShiftEncoding(int32_t aEncoding, char* aDest,
+                                           int32_t* aDestLength) {
+  if (aEncoding == mEncoding) {
+    *aDestLength = 0;
+    return NS_OK;
+  }
+
+  nsresult res = NS_OK;
+  char* dest = aDest;
+  char* destEnd = aDest + *aDestLength;
+
+  if (mEncStep != 0) {
+    if (dest >= destEnd) return NS_OK_UENC_MOREOUTPUT;
+    *(dest++) = ValueToChar(mEncBits);
+    mEncStep = 0;
+    mEncBits = 0;
+  }
+
+  if (dest >= destEnd) {
+    res = NS_OK_UENC_MOREOUTPUT;
+  } else {
+    switch (aEncoding) {
+      case 0:
+        *(dest++) = '-';
+        mEncStep = 0;
+        mEncBits = 0;
+        break;
+      case 1:
+        *(dest++) = mEscChar;
+        break;
+    }
+    mEncoding = aEncoding;
+  }
+
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+nsresult nsBasicUTF7Encoder::EncodeDirect(const char16_t* aSrc,
+                                          int32_t* aSrcLength, char* aDest,
+                                          int32_t* aDestLength) {
+  nsresult res = NS_OK;
+  const char16_t* src = aSrc;
+  const char16_t* srcEnd = aSrc + *aSrcLength;
+  char* dest = aDest;
+  char* destEnd = aDest + *aDestLength;
+  char16_t ch;
+
+  while (src < srcEnd) {
+    ch = *src;
+
+    // stop when we reach Unicode chars
+    if (!DirectEncodable(ch)) break;
+
+    if (ch == mEscChar) {
+      // special case for the escape char
+      if (destEnd - dest < 1) {
+        res = NS_OK_UENC_MOREOUTPUT;
+        break;
+      } else {
+        *dest++ = (char)ch;
+        *dest++ = (char)'-';
+        src++;
+      }
+    } else {
+      // classic direct encoding
+      if (dest >= destEnd) {
+        res = NS_OK_UENC_MOREOUTPUT;
+        break;
+      } else {
+        *dest++ = (char)ch;
+        src++;
+      }
+    }
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+nsresult nsBasicUTF7Encoder::EncodeBase64(const char16_t* aSrc,
+                                          int32_t* aSrcLength, char* aDest,
+                                          int32_t* aDestLength) {
+  nsresult res = NS_OK;
+  const char16_t* src = aSrc;
+  const char16_t* srcEnd = aSrc + *aSrcLength;
+  char* dest = aDest;
+  char* destEnd = aDest + *aDestLength;
+  char16_t ch;
+  uint32_t value;
+
+  while (src < srcEnd) {
+    ch = *src;
+
+    // stop when we reach printable US-ASCII chars
+    if (DirectEncodable(ch)) break;
+
+    switch (mEncStep) {
+      case 0:
+        if (destEnd - dest < 2) {
+          res = NS_OK_UENC_MOREOUTPUT;
+          break;
+        }
+        value = ch >> 10;
+        *(dest++) = ValueToChar(value);
+        value = (ch >> 4) & 0x3f;
+        *(dest++) = ValueToChar(value);
+        mEncBits = (ch & 0x0f) << 2;
+        break;
+      case 1:
+        if (destEnd - dest < 3) {
+          res = NS_OK_UENC_MOREOUTPUT;
+          break;
+        }
+        value = mEncBits + (ch >> 14);
+        *(dest++) = ValueToChar(value);
+        value = (ch >> 8) & 0x3f;
+        *(dest++) = ValueToChar(value);
+        value = (ch >> 2) & 0x3f;
+        *(dest++) = ValueToChar(value);
+        mEncBits = (ch & 0x03) << 4;
+        break;
+      case 2:
+        if (destEnd - dest < 3) {
+          res = NS_OK_UENC_MOREOUTPUT;
+          break;
+        }
+        value = mEncBits + (ch >> 12);
+        *(dest++) = ValueToChar(value);
+        value = (ch >> 6) & 0x3f;
+        *(dest++) = ValueToChar(value);
+        value = ch & 0x3f;
+        *(dest++) = ValueToChar(value);
+        mEncBits = 0;
+        break;
+    }
+
+    if (res != NS_OK) break;
+
+    src++;
+    (++mEncStep) %= 3;
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+char nsBasicUTF7Encoder::ValueToChar(uint32_t aValue) {
+  if (aValue < 26)
+    return (char)('A' + aValue);
+  else if (aValue < 26 + 26)
+    return (char)('a' + aValue - 26);
+  else if (aValue < 26 + 26 + 10)
+    return (char)('0' + aValue - 26 - 26);
+  else if (aValue == 26 + 26 + 10)
+    return '+';
+  else if (aValue == 26 + 26 + 10 + 1)
+    return mLastChar;
+  else
+    return -1;
+}
+
+bool nsBasicUTF7Encoder::DirectEncodable(char16_t aChar) {
+  // spec says: printable US-ASCII chars
+  if ((aChar >= 0x20) && (aChar <= 0x7e))
+    return true;
+  else
+    return false;
+}
+
+//----------------------------------------------------------------------
+// Subclassing of nsEncoderSupport class [implementation]
+
+NS_IMETHODIMP nsBasicUTF7Encoder::ConvertNoBuffNoErr(const char16_t* aSrc,
+                                                     int32_t* aSrcLength,
+                                                     char* aDest,
+                                                     int32_t* aDestLength) {
+  nsresult res = NS_OK;
+  const char16_t* src = aSrc;
+  const char16_t* srcEnd = aSrc + *aSrcLength;
+  char* dest = aDest;
+  char* destEnd = aDest + *aDestLength;
+  int32_t bcr, bcw;
+  char16_t ch;
+  int32_t enc;
+
+  while (src < srcEnd) {
+    // find the encoding for the next char
+    ch = *src;
+    if (DirectEncodable(ch))
+      enc = ENC_DIRECT;
+    else
+      enc = ENC_BASE64;
+
+    // if necessary, shift into the required encoding
+    bcw = destEnd - dest;
+    res = ShiftEncoding(enc, dest, &bcw);
+    dest += bcw;
+    if (res != NS_OK) break;
+
+    // now encode (as much as you can)
+    bcr = srcEnd - src;
+    bcw = destEnd - dest;
+    if (enc == ENC_DIRECT)
+      res = EncodeDirect(src, &bcr, dest, &bcw);
+    else
+      res = EncodeBase64(src, &bcr, dest, &bcw);
+    src += bcr;
+    dest += bcw;
+
+    if (res != NS_OK) break;
+  }
+
+  *aSrcLength = src - aSrc;
+  *aDestLength = dest - aDest;
+  return res;
+}
+
+NS_IMETHODIMP nsBasicUTF7Encoder::FinishNoBuff(char* aDest,
+                                               int32_t* aDestLength) {
+  return ShiftEncoding(ENC_DIRECT, aDest, aDestLength);
+}
+
+NS_IMETHODIMP nsBasicUTF7Encoder::Reset() {
+  mEncoding = ENC_DIRECT;
+  mEncBits = 0;
+  mEncStep = 0;
+  return NS_OK;
+}
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToUTF7 [implementation]
+
+nsUnicodeToUTF7::nsUnicodeToUTF7() : nsBasicUTF7Encoder('/', '+') {}
+
+bool nsUnicodeToUTF7::DirectEncodable(char16_t aChar) {
+  if ((aChar >= 'A') && (aChar <= 'Z'))
+    return true;
+  else if ((aChar >= 'a') && (aChar <= 'z'))
+    return true;
+  else if ((aChar >= '0') && (aChar <= '9'))
+    return true;
+  else if ((aChar >= 39) && (aChar <= 41))
+    return true;
+  else if ((aChar >= 44) && (aChar <= 47))
+    return true;
+  else if (aChar == 58)
+    return true;
+  else if (aChar == 63)
+    return true;
+  else if (aChar == ' ')
+    return true;
+  else if (aChar == 9)
+    return true;
+  else if (aChar == 13)
+    return true;
+  else if (aChar == 10)
+    return true;
+  else if (aChar == 60)
+    return true;  // '<'
+  else if (aChar == 33)
+    return true;  // '!'
+  else if (aChar == 34)
+    return true;  // '"'
+  else if (aChar == 62)
+    return true;  // '>'
+  else if (aChar == 61)
+    return true;  // '='
+  else if (aChar == 59)
+    return true;  // ';'
+  else if (aChar == 91)
+    return true;  // '['
+  else if (aChar == 93)
+    return true;  // ']'
+  else
+    return false;
+}
diff --git a/comm/mailnews/intl/nsUnicodeToUTF7.h b/comm/mailnews/intl/nsUnicodeToUTF7.h
new file mode 100644
index 0000000000..423bfa8198
--- /dev/null
+++ b/comm/mailnews/intl/nsUnicodeToUTF7.h
@@ -0,0 +1,69 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsUnicodeToUTF7_h___
+#define nsUnicodeToUTF7_h___
+
+//----------------------------------------------------------------------
+// Class nsBasicUTF7Encoder [declaration]
+
+/**
+ * Basic class for a character set converter from Unicode to UTF-7.
+ *
+ * @created         03/Jun/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsBasicUTF7Encoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsBasicUTF7Encoder(char aLastChar, char aEscChar);
+  NS_IMETHOD ConvertNoBuffNoErr(const char16_t* aSrc, int32_t* aSrcLength,
+                                char* aDest, int32_t* aDestLength);
+  NS_IMETHOD FinishNoBuff(char* aDest, int32_t* aDestLength);
+
+ protected:
+  int32_t mEncoding;  // current encoding
+  uint32_t mEncBits;
+  int32_t mEncStep;
+  char mLastChar;
+  char mEscChar;
+
+  nsresult ShiftEncoding(int32_t aEncoding, char* aDest, int32_t* aDestLength);
+  nsresult EncodeDirect(const char16_t* aSrc, int32_t* aSrcLength, char* aDest,
+                        int32_t* aDestLength);
+  nsresult EncodeBase64(const char16_t* aSrc, int32_t* aSrcLength, char* aDest,
+                        int32_t* aDestLength);
+  char ValueToChar(uint32_t aValue);
+  virtual bool DirectEncodable(char16_t aChar);
+
+  //--------------------------------------------------------------------
+  // Subclassing of nsEncoderSupport class [declaration]
+
+  NS_IMETHOD Reset();
+};
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToUTF7 [declaration]
+
+/**
+ * A character set converter from Unicode to UTF-7.
+ *
+ * @created         03/Jun/1999
+ * @author  Catalin Rotaru [CATA]
+ */
+class nsUnicodeToUTF7 : public nsBasicUTF7Encoder {
+ public:
+  /**
+   * Class constructor.
+   */
+  nsUnicodeToUTF7();
+
+ protected:
+  virtual bool DirectEncodable(char16_t aChar);
+};
+
+#endif /* nsUnicodeToUTF7_h___ */
diff --git a/comm/mailnews/intl/test/moz.build b/comm/mailnews/intl/test/moz.build
new file mode 100644
index 0000000000..6b37fdbe09
--- /dev/null
+++ b/comm/mailnews/intl/test/moz.build
@@ -0,0 +1,6 @@
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPCSHELL_TESTS_MANIFESTS += ["unit/xpcshell.ini"]
diff --git a/comm/mailnews/intl/test/unit/head_CharsetConversionTests.js b/comm/mailnews/intl/test/unit/head_CharsetConversionTests.js
new file mode 100644
index 0000000000..f1ae6c7155
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/head_CharsetConversionTests.js
@@ -0,0 +1,46 @@
+var CC = Components.Constructor;
+
+function CreateScriptableConverter() {
+  var ScriptableUnicodeConverter = CC(
+    "@mozilla.org/intl/scriptableunicodeconverter",
+    "nsIScriptableUnicodeConverter"
+  );
+
+  return new ScriptableUnicodeConverter();
+}
+
+function checkDecode(converter, charset, inText, expectedText) {
+  let manager = Cc["@mozilla.org/charset-converter-manager;1"].getService(
+    Ci.nsICharsetConverterManager
+  );
+
+  try {
+    converter.charset = manager.getCharsetAlias(charset);
+  } catch (e) {
+    converter.charset = "iso-8859-1";
+  }
+
+  dump("testing decoding from " + charset + " to Unicode.\n");
+  try {
+    var outText = converter.ConvertToUnicode(inText) + converter.Finish();
+  } catch (e) {
+    outText = "\ufffd";
+  }
+  Assert.equal(outText, expectedText);
+}
+
+function checkEncode(converter, charset, inText, expectedText) {
+  let manager = Cc["@mozilla.org/charset-converter-manager;1"].getService(
+    Ci.nsICharsetConverterManager
+  );
+
+  try {
+    converter.charset = manager.getCharsetAlias(charset);
+  } catch (e) {
+    converter.charset = "iso-8859-1";
+  }
+
+  dump("testing encoding from Unicode to " + charset + "\n");
+  var outText = converter.ConvertFromUnicode(inText) + converter.Finish();
+  Assert.equal(outText, expectedText);
+}
diff --git a/comm/mailnews/intl/test/unit/test_decode_utf-7.js b/comm/mailnews/intl/test/unit/test_decode_utf-7.js
new file mode 100644
index 0000000000..e81dd137e6
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/test_decode_utf-7.js
@@ -0,0 +1,23 @@
+// Tests conversion from UTF-7 to Unicode. The conversion should fail!
+
+var inString =
+  "+LGI--+ITIipSIp- +AocCeQ-oddns +Ad0CjQ- s+ATECZQKH- p+AlAB3QJ5- u+AlACVA- no+Ao4- +Al8-I";
+
+var expectedString =
+  "+LGI--+ITIipSIp- +AocCeQ-oddns +Ad0CjQ- s+ATECZQKH- p+AlAB3QJ5- u+AlACVA- no+Ao4- +Al8-I";
+
+var aliases = [
+  "UTF-7",
+  "utf-7",
+  "x-unicode-2-0-utf-7",
+  "unicode-2-0-utf-7",
+  "unicode-1-1-utf-7",
+  "csunicode11utf7",
+];
+
+function run_test() {
+  let converter = CreateScriptableConverter();
+  for (let i = 0; i < aliases.length; ++i) {
+    checkDecode(converter, aliases[i], inString, expectedString);
+  }
+}
diff --git a/comm/mailnews/intl/test/unit/test_decode_utf-7_internal.js b/comm/mailnews/intl/test/unit/test_decode_utf-7_internal.js
new file mode 100644
index 0000000000..e31f0f8840
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/test_decode_utf-7_internal.js
@@ -0,0 +1,30 @@
+// Tests conversion from UTF-7 to Unicode.
+
+var inString =
+  "+LGI--+ITIipSIp- +AocCeQ-oddns +Ad0CjQ- s+ATECZQKH- p+AlAB3QJ5- u+AlACVA- no+Ao4- +Al8-I";
+
+var expectedString =
+  "\u2C62-\u2132\u22A5\u2229 \u0287\u0279oddns \u01DD\u028D s\u0131\u0265\u0287 p\u0250\u01DD\u0279 u\u0250\u0254 no\u028E \u025FI";
+
+var aliases = [
+  "UTF-7",
+  "utf-7",
+  "x-unicode-2-0-utf-7",
+  "unicode-2-0-utf-7",
+  "unicode-1-1-utf-7",
+  "csunicode11utf7",
+];
+function run_test() {
+  let manager = Cc["@mozilla.org/charset-converter-manager;1"].getService(
+    Ci.nsICharsetConverterManager
+  );
+  let converter = CreateScriptableConverter();
+  converter.isInternal = true;
+  for (let i = 0; i < aliases.length; ++i) {
+    if (manager.getCharsetAlias(aliases[i]).toLowerCase() == "utf-7") {
+      Assert.equal(manager.utf7ToUnicode(inString), expectedString);
+    } else {
+      checkDecode(converter, aliases[i], inString, expectedString);
+    }
+  }
+}
diff --git a/comm/mailnews/intl/test/unit/test_encode_utf-7.js b/comm/mailnews/intl/test/unit/test_encode_utf-7.js
new file mode 100644
index 0000000000..1acc8957bd
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/test_encode_utf-7.js
@@ -0,0 +1,22 @@
+// Tests conversion from Unicode to UTF-7. The conversion should fail!
+
+var inString =
+  "\u2C62-\u2132\u22A5\u2229 \u0287\u0279oddns \u01DD\u028D s\u0131\u0265\u0287 p\u0250\u01DD\u0279 u\u0250\u0254 no\u028E \u025FI";
+
+var expectedString = "?-??? ??oddns ?? s??? p??? u?? no? ?I";
+
+var aliases = [
+  "UTF-7",
+  "utf-7",
+  "x-unicode-2-0-utf-7",
+  "unicode-2-0-utf-7",
+  "unicode-1-1-utf-7",
+  "csunicode11utf7",
+];
+
+function run_test() {
+  let converter = CreateScriptableConverter();
+  for (let i = 0; i < aliases.length; ++i) {
+    checkEncode(converter, aliases[i], inString, expectedString);
+  }
+}
diff --git a/comm/mailnews/intl/test/unit/test_encode_utf-7_internal.js b/comm/mailnews/intl/test/unit/test_encode_utf-7_internal.js
new file mode 100644
index 0000000000..31af29c30b
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/test_encode_utf-7_internal.js
@@ -0,0 +1,24 @@
+// Tests conversion from Unicode to UTF-7.
+
+var inString =
+  "\u2C62-\u2132\u22A5\u2229 \u0287\u0279oddns \u01DD\u028D s\u0131\u0265\u0287 p\u0250\u01DD\u0279 u\u0250\u0254 no\u028E \u025FI";
+
+var expectedString =
+  "+LGI--+ITIipSIp- +AocCeQ-oddns +Ad0CjQ- s+ATECZQKH- p+AlAB3QJ5- u+AlACVA- no+Ao4- +Al8-I";
+
+var aliases = [
+  "UTF-7",
+  "utf-7",
+  "x-unicode-2-0-utf-7",
+  "unicode-2-0-utf-7",
+  "unicode-1-1-utf-7",
+  "csunicode11utf7",
+];
+
+function run_test() {
+  let converter = CreateScriptableConverter();
+  converter.isInternal = true;
+  for (let i = 0; i < aliases.length; ++i) {
+    checkEncode(converter, aliases[i], inString, expectedString);
+  }
+}
diff --git a/comm/mailnews/intl/test/unit/xpcshell.ini b/comm/mailnews/intl/test/unit/xpcshell.ini
new file mode 100644
index 0000000000..cbc671669c
--- /dev/null
+++ b/comm/mailnews/intl/test/unit/xpcshell.ini
@@ -0,0 +1,10 @@
+[DEFAULT]
+head = head_CharsetConversionTests.js
+tail =
+
+[test_decode_utf-7.js]
+[test_decode_utf-7_internal.js]
+[test_encode_utf-7.js]
+[test_encode_utf-7_internal.js]
+# Disabled per bug 1363281: No scriptable converter for UTF-7 exists any more.
+skip-if = true