[Android] Handle null values in BuildInfo.

base/android/build_info.cc

 // Copyright (c) 2012 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/build_info.h"
 
 #include <string>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "jni/BuildInfo_jni.h"
 
 namespace {
 
-// The caller takes ownership of the returned const char*.
+// We are leaking these strings.
 const char* StrDupJString(const base::android::JavaRef<jstring>& java_string) {
+  // Some of the Java methods on BuildInfo can return null
+  // (https://crbug.com/601081), which can't be represented as a std::string, so
+  // use an empty string instead.
+  // TODO(bauerb): Do this only for methods that can legitimately return null.
+  if (java_string.is_null())
+    return "";
+
   std::string str = ConvertJavaStringToUTF8(java_string);
   return strdup(str.c_str());
 }
 
 }  // namespace
 
 namespace base {
 namespace android {
 
 struct BuildInfoSingletonTraits {
@@ skipping 50 matching lines @@
   java_exception_info_ = nullptr;
 }
 
 // static
 bool BuildInfo::RegisterBindings(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace base