1 files changed, 90 insertions, 0 deletions
diff --git a/mailnews/mime/src/jsmime.jsm b/mailnews/mime/src/jsmime.jsm
new file mode 100644
index 000000000..70728fe9c
--- /dev/null
+++ b/mailnews/mime/src/jsmime.jsm
@@ -0,0 +1,90 @@
+/* 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/. */
+// vim:set ts=2 sw=2 sts=2 et ft=javascript:
+
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+/**
+ * This file exports the JSMime code, polyfilling code as appropriate for use in
+ * Gecko.
+ */
+
+// Load the core MIME parser. Since it doesn't define EXPORTED_SYMBOLS, we must
+// use the subscript loader instead.
+Services.scriptloader.loadSubScript("resource:///modules/jsmime/jsmime.js");
+
+var EXPORTED_SYMBOLS = ["jsmime"];
+
+
+// A polyfill to support non-encoding-spec charsets. Since the only converter
+// available to us from JavaScript has a very, very weak and inflexible API, we
+// choose to rely on the regular text decoder unless absolutely necessary.
+// support non-encoding-spec charsets.
+function FakeTextDecoder(label="UTF-8", options = {}) {
+  this._reset(label);
+  // So nsIScriptableUnicodeConverter only gives us fatal=false, unless we are
+  // using UTF-8, where we only get fatal=true. The internals of said class tell
+  // us to use a C++-only class if we need better behavior.
+}
+FakeTextDecoder.prototype = {
+  _reset: function (label) {
+    this._encoder = Components.classes[
+      "@mozilla.org/intl/scriptableunicodeconverter"]
+      .createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
+    this._encoder.isInternal = true;
+    let manager = Components.classes[
+      "@mozilla.org/charset-converter-manager;1"]
+      .createInstance(Components.interfaces.nsICharsetConverterManager);
+    this._encoder.charset = manager.getCharsetAlias(label);
+  },
+  get encoding() { return this._encoder.charset; },
+  decode: function (input, options = {}) {
+    let more = 'stream' in options ? options.stream : false;
+    let result = "";
+    if (input !== undefined) {
+      let data = new Uint8Array(input);
+      result = this._encoder.convertFromByteArray(data, data.length);
+    }
+    // This isn't quite right--it won't handle errors if there are a few
+    // remaining bytes in the buffer, but it's the best we can do.
+    if (!more)
+      this._reset(this.encoding);
+    return result;
+  },
+};
+
+var RealTextDecoder = TextDecoder;
+function FallbackTextDecoder(charset, options) {
+  try {
+    return new RealTextDecoder(charset, options);
+  } catch (e) {
+    return new FakeTextDecoder(charset, options);
+  }
+}
+
+TextDecoder = FallbackTextDecoder;
+
+
+// The following code loads custom MIME encoders.
+var CATEGORY_NAME = "custom-mime-encoder";
+Services.obs.addObserver(function (subject, topic, data) {
+  subject = subject.QueryInterface(Components.interfaces.nsISupportsCString)
+                   .data;
+  if (data == CATEGORY_NAME) {
+    let url = catman.getCategoryEntry(CATEGORY_NAME, subject);
+    Services.scriptloader.loadSubScript(url, {}, "UTF-8");
+  }
+}, "xpcom-category-entry-added", false);
+
+var catman = Components.classes["@mozilla.org/categorymanager;1"]
+                       .getService(Components.interfaces.nsICategoryManager);
+
+var entries = catman.enumerateCategory(CATEGORY_NAME);
+while (entries.hasMoreElements()) {
+  let string = entries.getNext()
+                      .QueryInterface(Components.interfaces.nsISupportsCString)
+                      .data;
+  let url = catman.getCategoryEntry(CATEGORY_NAME, string);
+  Services.scriptloader.loadSubScript(url, {}, "UTF-8");
+}