Refactor ScopedJavaRef

base/android/jni_string.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/android/jni_string.h"
 
 #include "base/android/jni_android.h"
 #include "base/logging.h"
 #include "base/utf_string_conversions.h"
 
 namespace base {
 namespace android {
 
 std::string ConvertJavaStringToUTF8(JNIEnv* env, jstring str) {
   // JNI's GetStringUTFChars() returns strings in Java-modified UTF8, so we
   // instead get the String in UTF16 and convert using our own utility function.
   return UTF16ToUTF8(ConvertJavaStringToUTF16(env, str));
 }
 
-jstring ConvertUTF8ToJavaString(JNIEnv* env, const std::string& str) {
-  jstring result = env->NewStringUTF(str.c_str());
-  CheckException(env);
-  return result;
+jstring ConvertUTF8ToJavaString(JNIEnv* env, const base::StringPiece& str) {
+  // JNI's NewStringUTF expects "modified" UTF8 so instead create the string
+  // via our own UTF16 conversion utility.
+  // Further, Dalvik requires the string passed into NewStringUTF() to come from
+  // a trusted source. We can't guarantee that all UTF8 will be sanitized before
+  // it gets here, so constructing via UTF16 side-steps this issue.
+  // (Dalvik stores strings internally as UTF16 anyway, so there shouldn't be
+  // a significant performance hit by doing it this way).
+  return ConvertUTF16ToJavaString(env, UTF8ToUTF16(str));
 }
 
 string16 ConvertJavaStringToUTF16(JNIEnv* env, jstring str) {
   const jchar* chars = env->GetStringChars(str, NULL);
   DCHECK(chars);
   // GetStringChars isn't required to NULL-terminate the strings
   // it returns, so the length must be explicitly checked.
   string16 result(chars, env->GetStringLength(str));
   env->ReleaseStringChars(str, chars);
   CheckException(env);
   return result;
 }
 
 jstring ConvertUTF16ToJavaString(JNIEnv* env, const string16& str) {
   jstring result = env->NewString(str.data(), str.length());
   CheckException(env);
   return result;
 }
 
 }  // namespace android
 }  // namespace base