Fix joyent/node#8683

src/node_buffer.cc

@@ -119,12 +119,24 @@ size_t Length(Handle<Object> obj) {
 
 Local<Object> New(Isolate* isolate, Handle<String> string, enum encoding enc) {
   EscapableHandleScope scope(isolate);
-
-  size_t length = StringBytes::Size(isolate, string, enc);
+  Local<String> tmp_string;
+
+  if (string->IsExternalAscii()) {
+    const String::ExternalAsciiStringResource* ext;
+    ext = string->GetExternalAsciiStringResource();
+    tmp_string = String::NewFromOneByte(isolate, reinterpret_cast<const uint8_t*>(ext->data()), String::NewStringType::kNormalString, ext->length());
+  } else if (string->IsExternal()) {
+    const String::ExternalStringResource* ext;
+    ext = string->GetExternalStringResource();
+    tmp_string = String::NewFromTwoByte(isolate, ext->data(), String::NewStringType::kNormalString, ext->length());
+  } else {
+    tmp_string = string;
+  }
+  size_t length = StringBytes::Size(isolate, tmp_string, enc);
 
   Local<Object> buf = New(length);
   char* data = Buffer::Data(buf);
-  StringBytes::Write(isolate, data, length, string, enc);
+  StringBytes::Write(isolate, data, length, tmp_string, enc);
 
   return scope.Escape(buf);
 }

src/string_bytes.cc

@@ -304,6 +304,14 @@ size_t StringBytes::Write(Isolate* isolate,
 
   CHECK(val->IsString() == true);
   Local<String> str = val.As<String>();
+  bool is_extern_ascii = is_extern && str->IsExternalAscii();
+  if (is_extern) {
+    if (is_extern_ascii) {
+      str = String::NewFromOneByte(isolate, reinterpret_cast<const uint8_t*>(data), String::NewStringType::kNormalString, len);
+    } else {
+      str = String::NewFromTwoByte(isolate, reinterpret_cast<const uint16_t*>(data), String::NewStringType::kNormalString, len);
+    }
+  }
   len = len < buflen ? len : buflen;
 
   int flags = String::NO_NULL_TERMINATION |
@@ -313,31 +321,20 @@ size_t StringBytes::Write(Isolate* isolate,
     case ASCII:
     case BINARY:
     case BUFFER:
-      if (is_extern)
-        memcpy(buf, data, len);
-      else
-        len = str->WriteOneByte(reinterpret_cast<uint8_t*>(buf),
-                                0,
-                                buflen,
-                                flags);
+      len = str->WriteOneByte(reinterpret_cast<uint8_t*>(buf),
+                              0,
+                              buflen,
+                              flags);
       if (chars_written != NULL)
         *chars_written = len;
       break;
 
     case UTF8:
-      if (is_extern)
-        // TODO(tjfontaine) should this validate invalid surrogate pairs as
-        // well?
-        memcpy(buf, data, len);
-      else
-        len = str->WriteUtf8(buf, buflen, chars_written, WRITE_UTF8_FLAGS);
+      len = str->WriteUtf8(buf, buflen, chars_written, WRITE_UTF8_FLAGS);
       break;
 
     case UCS2:
-      if (is_extern)
-        memcpy(buf, data, len * 2);
-      else
-        len = str->Write(reinterpret_cast<uint16_t*>(buf), 0, buflen, flags);
+      len = str->Write(reinterpret_cast<uint16_t*>(buf), 0, buflen, flags);
       if (IsBigEndian()) {
         // Node's "ucs2" encoding wants LE character data stored in
         // the Buffer, so we need to reorder on BE platforms.  See
@@ -354,24 +351,20 @@ size_t StringBytes::Write(Isolate* isolate,
       break;
 
     case BASE64:
-      if (is_extern) {
-        len = base64_decode(buf, buflen, data, extlen);
-      } else {
+      do {
         String::Value value(str);
         len = base64_decode(buf, buflen, *value, value.length());
-      }
+      } while (0);
       if (chars_written != NULL) {
         *chars_written = len;
       }
       break;
 
     case HEX:
-      if (is_extern) {
-        len = hex_decode(buf, buflen, data, extlen);
-      } else {
+      do {
         String::Value value(str);
         len = hex_decode(buf, buflen, *value, value.length());
-      }
+      } while (0);
       if (chars_written != NULL) {
         *chars_written = len * 2;
       }
@@ -459,10 +452,17 @@ size_t StringBytes::Size(Isolate* isolate,
     return Buffer::Length(val);
 
   const char* data;
-  if (GetExternalParts(isolate, val, &data, &data_size))
-    return data_size;
+  bool is_extern = GetExternalParts(isolate, val, &data, &data_size);
 
   Local<String> str = val->ToString();
+  bool is_extern_ascii = is_extern && str->IsExternalAscii();
+  if (is_extern) {
+    if (is_extern_ascii) {
+      str = String::NewFromOneByte(isolate, reinterpret_cast<const uint8_t*>(data), String::NewStringType::kNormalString, data_size);
+    } else {
+      str = String::NewFromTwoByte(isolate, reinterpret_cast<const uint16_t*>(data), String::NewStringType::kNormalString, data_size);
+    }
+  }
 
   switch (encoding) {
     case BINARY:

test/simple/test-v8-externalize-string.js

@@ -0,0 +1,35 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+// Flags: --expose_externalize_string
+
+var common = require('../common');
+var assert = require('assert');
+
+assert(typeof externalizeString === 'function', 'Run this test with --expose_externalize_string.');
+
+var str = '中';
+var buf = new Buffer(str);
+assert.equal(buf.toString('hex'), 'e4b8ad');
+
+externalizeString(str, true); // force two bytes string
+var extbuf = new Buffer(str); // convert string to utf8 buffer
+assert.equal(extbuf.toString('hex'), 'e4b8ad');