down integrate to svn

1 files changed, 870 insertions, 25 deletions

diff --git a/src/google/protobuf/descriptor_unittest.cc b/src/google/protobuf/descriptor_unittest.cc
index 86e6a49d..9b77fbe8 100644
--- a/src/google/protobuf/descriptor_unittest.cc
+++ b/src/google/protobuf/descriptor_unittest.cc
@@ -646,6 +646,104 @@ TEST_F(DescriptorTest, FieldEnumType) {
 
 // ===================================================================
 
+// Test simple flat messages and fields.
+class OneofDescriptorTest : public testing::Test {
+ protected:
+  virtual void SetUp() {
+    // Build descriptors for the following definitions:
+    //
+    //   package garply;
+    //   message TestOneof {
+    //     optional int32 a = 1;
+    //     oneof foo {
+    //       string b = 2;
+    //       TestOneof c = 3;
+    //     }
+    //     oneof bar {
+    //       float d = 4;
+    //     }
+    //   }
+
+    FileDescriptorProto baz_file;
+    baz_file.set_name("baz.proto");
+    baz_file.set_package("garply");
+
+    DescriptorProto* oneof_message = AddMessage(&baz_file, "TestOneof");
+    oneof_message->add_oneof_decl()->set_name("foo");
+    oneof_message->add_oneof_decl()->set_name("bar");
+
+    AddField(oneof_message, "a", 1,
+             FieldDescriptorProto::LABEL_OPTIONAL,
+             FieldDescriptorProto::TYPE_INT32);
+    AddField(oneof_message, "b", 2,
+             FieldDescriptorProto::LABEL_OPTIONAL,
+             FieldDescriptorProto::TYPE_STRING);
+    oneof_message->mutable_field(1)->set_oneof_index(0);
+    AddField(oneof_message, "c", 3,
+             FieldDescriptorProto::LABEL_OPTIONAL,
+             FieldDescriptorProto::TYPE_MESSAGE);
+    oneof_message->mutable_field(2)->set_oneof_index(0);
+    oneof_message->mutable_field(2)->set_type_name("TestOneof");
+
+    AddField(oneof_message, "d", 4,
+             FieldDescriptorProto::LABEL_OPTIONAL,
+             FieldDescriptorProto::TYPE_FLOAT);
+    oneof_message->mutable_field(3)->set_oneof_index(1);
+
+    // Build the descriptors and get the pointers.
+    baz_file_ = pool_.BuildFile(baz_file);
+    ASSERT_TRUE(baz_file_ != NULL);
+
+    ASSERT_EQ(1, baz_file_->message_type_count());
+    oneof_message_ = baz_file_->message_type(0);
+
+    ASSERT_EQ(2, oneof_message_->oneof_decl_count());
+    oneof_ = oneof_message_->oneof_decl(0);
+    oneof2_ = oneof_message_->oneof_decl(1);
+
+    ASSERT_EQ(4, oneof_message_->field_count());
+    a_ = oneof_message_->field(0);
+    b_ = oneof_message_->field(1);
+    c_ = oneof_message_->field(2);
+    d_ = oneof_message_->field(3);
+  }
+
+  DescriptorPool pool_;
+
+  const FileDescriptor* baz_file_;
+
+  const Descriptor* oneof_message_;
+
+  const OneofDescriptor* oneof_;
+  const OneofDescriptor* oneof2_;
+  const FieldDescriptor* a_;
+  const FieldDescriptor* b_;
+  const FieldDescriptor* c_;
+  const FieldDescriptor* d_;
+  const FieldDescriptor* e_;
+  const FieldDescriptor* f_;
+};
+
+TEST_F(OneofDescriptorTest, Normal) {
+  EXPECT_EQ("foo", oneof_->name());
+  EXPECT_EQ("garply.TestOneof.foo", oneof_->full_name());
+  EXPECT_EQ(0, oneof_->index());
+  ASSERT_EQ(2, oneof_->field_count());
+  EXPECT_EQ(b_, oneof_->field(0));
+  EXPECT_EQ(c_, oneof_->field(1));
+  EXPECT_TRUE(a_->containing_oneof() == NULL);
+  EXPECT_EQ(oneof_, b_->containing_oneof());
+  EXPECT_EQ(oneof_, c_->containing_oneof());
+}
+
+TEST_F(OneofDescriptorTest, FindByName) {
+  EXPECT_EQ(oneof_, oneof_message_->FindOneofByName("foo"));
+  EXPECT_EQ(oneof2_, oneof_message_->FindOneofByName("bar"));
+  EXPECT_TRUE(oneof_message_->FindOneofByName("no_such_oneof") == NULL);
+}
+
+// ===================================================================
+
 class StylizedFieldNamesTest : public testing::Test {
  protected:
   void SetUp() {
@@ -1516,6 +1614,40 @@ TEST_F(ExtensionDescriptorTest, FindAllExtensions) {
   EXPECT_EQ(39, extensions[3]->number());
 }
 
+TEST_F(ExtensionDescriptorTest, DuplicateFieldNumber) {
+  DescriptorPool pool;
+  FileDescriptorProto file_proto;
+  // Add "google/protobuf/descriptor.proto".
+  FileDescriptorProto::descriptor()->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+  // Add "foo.proto":
+  //   import "google/protobuf/descriptor.proto";
+  //   extend google.protobuf.FieldOptions {
+  //     optional int32 option1 = 1000;
+  //   }
+  file_proto.Clear();
+  file_proto.set_name("foo.proto");
+  file_proto.add_dependency("google/protobuf/descriptor.proto");
+  AddExtension(&file_proto, "google.protobuf.FieldOptions", "option1", 1000,
+               FieldDescriptorProto::LABEL_OPTIONAL,
+               FieldDescriptorProto::TYPE_INT32);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+  // Add "bar.proto":
+  //   import "google/protobuf/descriptor.proto";
+  //   extend google.protobuf.FieldOptions {
+  //     optional int32 option2 = 1000;
+  //   }
+  file_proto.Clear();
+  file_proto.set_name("bar.proto");
+  file_proto.add_dependency("google/protobuf/descriptor.proto");
+  AddExtension(&file_proto, "google.protobuf.FieldOptions", "option2", 1000,
+               FieldDescriptorProto::LABEL_OPTIONAL,
+               FieldDescriptorProto::TYPE_INT32);
+  // Currently we only generate a warning for conflicting extension numbers.
+  // TODO(xiaofeng): Change it to an error.
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+}
+
 // ===================================================================
 
 class MiscTest : public testing::Test {
@@ -1567,6 +1699,18 @@ class MiscTest : public testing::Test {
     return field != NULL ? field->cpp_type_name() : "";
   }
 
+  const Descriptor* GetMessageDescriptorForFieldType(
+      FieldDescriptor::Type type) {
+    const FieldDescriptor* field = GetFieldDescriptorOfType(type);
+    return field != NULL ? field->message_type() : NULL;
+  }
+
+  const EnumDescriptor* GetEnumDescriptorForFieldType(
+    FieldDescriptor::Type type) {
+    const FieldDescriptor* field = GetFieldDescriptorOfType(type);
+    return field != NULL ? field->enum_type() : NULL;
+  }
+
   scoped_ptr<DescriptorPool> pool_;
 };
 
@@ -1595,6 +1739,31 @@ TEST_F(MiscTest, TypeNames) {
   EXPECT_STREQ("sint64"  , GetTypeNameForFieldType(FD::TYPE_SINT64  ));
 }
 
+TEST_F(MiscTest, StaticTypeNames) {
+  // Test that correct type names are returned.
+
+  typedef FieldDescriptor FD;  // avoid ugly line wrapping
+
+  EXPECT_STREQ("double"  , FD::TypeName(FD::TYPE_DOUBLE  ));
+  EXPECT_STREQ("float"   , FD::TypeName(FD::TYPE_FLOAT   ));
+  EXPECT_STREQ("int64"   , FD::TypeName(FD::TYPE_INT64   ));
+  EXPECT_STREQ("uint64"  , FD::TypeName(FD::TYPE_UINT64  ));
+  EXPECT_STREQ("int32"   , FD::TypeName(FD::TYPE_INT32   ));
+  EXPECT_STREQ("fixed64" , FD::TypeName(FD::TYPE_FIXED64 ));
+  EXPECT_STREQ("fixed32" , FD::TypeName(FD::TYPE_FIXED32 ));
+  EXPECT_STREQ("bool"    , FD::TypeName(FD::TYPE_BOOL    ));
+  EXPECT_STREQ("string"  , FD::TypeName(FD::TYPE_STRING  ));
+  EXPECT_STREQ("group"   , FD::TypeName(FD::TYPE_GROUP   ));
+  EXPECT_STREQ("message" , FD::TypeName(FD::TYPE_MESSAGE ));
+  EXPECT_STREQ("bytes"   , FD::TypeName(FD::TYPE_BYTES   ));
+  EXPECT_STREQ("uint32"  , FD::TypeName(FD::TYPE_UINT32  ));
+  EXPECT_STREQ("enum"    , FD::TypeName(FD::TYPE_ENUM    ));
+  EXPECT_STREQ("sfixed32", FD::TypeName(FD::TYPE_SFIXED32));
+  EXPECT_STREQ("sfixed64", FD::TypeName(FD::TYPE_SFIXED64));
+  EXPECT_STREQ("sint32"  , FD::TypeName(FD::TYPE_SINT32  ));
+  EXPECT_STREQ("sint64"  , FD::TypeName(FD::TYPE_SINT64  ));
+}
+
 TEST_F(MiscTest, CppTypes) {
   // Test that CPP types are assigned correctly.
 
@@ -1645,6 +1814,74 @@ TEST_F(MiscTest, CppTypeNames) {
   EXPECT_STREQ("int64"  , GetCppTypeNameForFieldType(FD::TYPE_SINT64  ));
 }
 
+TEST_F(MiscTest, StaticCppTypeNames) {
+  // Test that correct CPP type names are returned.
+
+  typedef FieldDescriptor FD;  // avoid ugly line wrapping
+
+  EXPECT_STREQ("int32"  , FD::CppTypeName(FD::CPPTYPE_INT32  ));
+  EXPECT_STREQ("int64"  , FD::CppTypeName(FD::CPPTYPE_INT64  ));
+  EXPECT_STREQ("uint32" , FD::CppTypeName(FD::CPPTYPE_UINT32 ));
+  EXPECT_STREQ("uint64" , FD::CppTypeName(FD::CPPTYPE_UINT64 ));
+  EXPECT_STREQ("double" , FD::CppTypeName(FD::CPPTYPE_DOUBLE ));
+  EXPECT_STREQ("float"  , FD::CppTypeName(FD::CPPTYPE_FLOAT  ));
+  EXPECT_STREQ("bool"   , FD::CppTypeName(FD::CPPTYPE_BOOL   ));
+  EXPECT_STREQ("enum"   , FD::CppTypeName(FD::CPPTYPE_ENUM   ));
+  EXPECT_STREQ("string" , FD::CppTypeName(FD::CPPTYPE_STRING ));
+  EXPECT_STREQ("message", FD::CppTypeName(FD::CPPTYPE_MESSAGE));
+}
+
+TEST_F(MiscTest, MessageType) {
+  // Test that message_type() is NULL for non-aggregate fields
+
+  typedef FieldDescriptor FD;  // avoid ugly line wrapping
+
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_DOUBLE  ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_FLOAT   ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_INT64   ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_UINT64  ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_INT32   ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_FIXED64 ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_FIXED32 ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_BOOL    ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_STRING  ));
+  EXPECT_TRUE(NULL != GetMessageDescriptorForFieldType(FD::TYPE_GROUP   ));
+  EXPECT_TRUE(NULL != GetMessageDescriptorForFieldType(FD::TYPE_MESSAGE ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_BYTES   ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_UINT32  ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_ENUM    ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_SFIXED32));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_SFIXED64));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_SINT32  ));
+  EXPECT_TRUE(NULL == GetMessageDescriptorForFieldType(FD::TYPE_SINT64  ));
+}
+
+TEST_F(MiscTest, EnumType) {
+  // Test that enum_type() is NULL for non-enum fields
+
+  typedef FieldDescriptor FD;  // avoid ugly line wrapping
+
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_DOUBLE  ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_FLOAT   ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_INT64   ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_UINT64  ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_INT32   ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_FIXED64 ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_FIXED32 ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_BOOL    ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_STRING  ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_GROUP   ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_MESSAGE ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_BYTES   ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_UINT32  ));
+  EXPECT_TRUE(NULL != GetEnumDescriptorForFieldType(FD::TYPE_ENUM    ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_SFIXED32));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_SFIXED64));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_SINT32  ));
+  EXPECT_TRUE(NULL == GetEnumDescriptorForFieldType(FD::TYPE_SINT64  ));
+}
+
+
 TEST_F(MiscTest, DefaultValues) {
   // Test that setting default values works.
   FileDescriptorProto file_proto;
@@ -1910,10 +2147,12 @@ class AllowUnknownDependenciesTest
 TEST_P(AllowUnknownDependenciesTest, PlaceholderFile) {
   ASSERT_EQ(2, foo_file_->dependency_count());
   EXPECT_EQ(bar_file_, foo_file_->dependency(0));
+  EXPECT_FALSE(bar_file_->is_placeholder());
 
   const FileDescriptor* baz_file = foo_file_->dependency(1);
   EXPECT_EQ("baz.proto", baz_file->name());
   EXPECT_EQ(0, baz_file->message_type_count());
+  EXPECT_TRUE(baz_file->is_placeholder());
 
   // Placeholder files should not be findable.
   EXPECT_EQ(bar_file_, pool_->FindFileByName(bar_file_->name()));
@@ -1923,19 +2162,20 @@ TEST_P(AllowUnknownDependenciesTest, PlaceholderFile) {
 TEST_P(AllowUnknownDependenciesTest, PlaceholderTypes) {
   ASSERT_EQ(FieldDescriptor::TYPE_MESSAGE, bar_field_->type());
   EXPECT_EQ(bar_type_, bar_field_->message_type());
+  EXPECT_FALSE(bar_type_->is_placeholder());
 
   ASSERT_EQ(FieldDescriptor::TYPE_MESSAGE, baz_field_->type());
   const Descriptor* baz_type = baz_field_->message_type();
   EXPECT_EQ("Baz", baz_type->name());
   EXPECT_EQ("Baz", baz_type->full_name());
-  EXPECT_EQ("Baz.placeholder.proto", baz_type->file()->name());
   EXPECT_EQ(0, baz_type->extension_range_count());
+  EXPECT_TRUE(baz_type->is_placeholder());
 
   ASSERT_EQ(FieldDescriptor::TYPE_ENUM, qux_field_->type());
   const EnumDescriptor* qux_type = qux_field_->enum_type();
   EXPECT_EQ("Qux", qux_type->name());
   EXPECT_EQ("corge.Qux", qux_type->full_name());
-  EXPECT_EQ("corge.Qux.placeholder.proto", qux_type->file()->name());
+  EXPECT_TRUE(qux_type->is_placeholder());
 
   // Placeholder types should not be findable.
   EXPECT_EQ(bar_type_, pool_->FindMessageTypeByName(bar_type_->full_name()));
@@ -1993,6 +2233,7 @@ TEST_P(AllowUnknownDependenciesTest, UnknownExtendee) {
   ASSERT_EQ(1, file->extension_count());
   const Descriptor* extendee = file->extension(0)->containing_type();
   EXPECT_EQ("UnknownType", extendee->name());
+  EXPECT_TRUE(extendee->is_placeholder());
   ASSERT_EQ(1, extendee->extension_range_count());
   EXPECT_EQ(1, extendee->extension_range(0)->start);
   EXPECT_EQ(FieldDescriptor::kMaxNumber + 1, extendee->extension_range(0)->end);
@@ -2111,13 +2352,13 @@ TEST_P(AllowUnknownDependenciesTest,
   const Descriptor* corge_desc = file->message_type(0);
   ASSERT_EQ("Corge", corge_desc->name());
   ASSERT_EQ(1, corge_desc->field_count());
+  EXPECT_FALSE(corge_desc->is_placeholder());
 
   const FieldDescriptor* quux_field = corge_desc->field(0);
   ASSERT_EQ(FieldDescriptor::TYPE_MESSAGE, quux_field->type());
   ASSERT_EQ("Quux", quux_field->message_type()->name());
   ASSERT_EQ("undeclared.Quux", quux_field->message_type()->full_name());
-  EXPECT_EQ("undeclared.Quux.placeholder.proto",
-            quux_field->message_type()->file()->name());
+  EXPECT_TRUE(quux_field->message_type()->is_placeholder());
   // The place holder type should not be findable.
   ASSERT_TRUE(pool_->FindMessageTypeByName("undeclared.Quux") == NULL);
 }
@@ -2167,7 +2408,7 @@ TEST(CustomOptions, OptionTypes) {
 
   options =
       &protobuf_unittest::CustomOptionMinIntegerValues::descriptor()->options();
-  EXPECT_FALSE(        options->GetExtension(protobuf_unittest::bool_opt));
+  EXPECT_EQ(false    , options->GetExtension(protobuf_unittest::bool_opt));
   EXPECT_EQ(kint32min, options->GetExtension(protobuf_unittest::int32_opt));
   EXPECT_EQ(kint64min, options->GetExtension(protobuf_unittest::int64_opt));
   EXPECT_EQ(0        , options->GetExtension(protobuf_unittest::uint32_opt));
@@ -2181,7 +2422,7 @@ TEST(CustomOptions, OptionTypes) {
 
   options =
       &protobuf_unittest::CustomOptionMaxIntegerValues::descriptor()->options();
-  EXPECT_TRUE(          options->GetExtension(protobuf_unittest::bool_opt));
+  EXPECT_EQ(true      , options->GetExtension(protobuf_unittest::bool_opt));
   EXPECT_EQ(kint32max , options->GetExtension(protobuf_unittest::int32_opt));
   EXPECT_EQ(kint64max , options->GetExtension(protobuf_unittest::int64_opt));
   EXPECT_EQ(kuint32max, options->GetExtension(protobuf_unittest::uint32_opt));
@@ -2389,6 +2630,170 @@ TEST(CustomOptions, MessageOptionThreeFieldsSet) {
   EXPECT_EQ(1234, options.GetExtension(protobuf_unittest::complex_opt1).foo());
 }
 
+TEST(CustomOptions, MessageOptionRepeatedLeafFieldSet) {
+  // This test verifies that repeated fields in custom options can be
+  // given multiple values by repeating the option with a different value.
+  // This test checks repeated leaf values. Each repeated custom value
+  // appears in a different uninterpreted_option, which will be concatenated
+  // when they are merged into the final option value.
+  DescriptorPool pool;
+
+  FileDescriptorProto file_proto;
+  FileDescriptorProto::descriptor()->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+  protobuf_unittest::TestMessageWithCustomOptions::descriptor()
+    ->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+  // The following represents the definition:
+  //
+  //   import "google/protobuf/unittest_custom_options.proto"
+  //   package protobuf_unittest;
+  //   message Foo {
+  //     option (complex_opt1).foo4 = 12;
+  //     option (complex_opt1).foo4 = 34;
+  //     option (complex_opt1).foo4 = 56;
+  //   }
+  ASSERT_TRUE(TextFormat::ParseFromString(
+    "name: \"custom_options_import.proto\" "
+    "package: \"protobuf_unittest\" "
+    "dependency: \"google/protobuf/unittest_custom_options.proto\" "
+    "message_type { "
+    "  name: \"Foo\" "
+    "  options { "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt1\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"foo4\" "
+    "        is_extension: false "
+    "      } "
+    "      positive_int_value: 12 "
+    "    } "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt1\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"foo4\" "
+    "        is_extension: false "
+    "      } "
+    "      positive_int_value: 34 "
+    "    } "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt1\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"foo4\" "
+    "        is_extension: false "
+    "      } "
+    "      positive_int_value: 56 "
+    "    } "
+    "  } "
+    "}",
+    &file_proto));
+
+  const FileDescriptor* file = pool.BuildFile(file_proto);
+  ASSERT_TRUE(file != NULL);
+  ASSERT_EQ(1, file->message_type_count());
+
+  const MessageOptions& options = file->message_type(0)->options();
+  EXPECT_EQ(3, options.GetExtension(protobuf_unittest::complex_opt1).foo4_size());
+  EXPECT_EQ(12, options.GetExtension(protobuf_unittest::complex_opt1).foo4(0));
+  EXPECT_EQ(34, options.GetExtension(protobuf_unittest::complex_opt1).foo4(1));
+  EXPECT_EQ(56, options.GetExtension(protobuf_unittest::complex_opt1).foo4(2));
+}
+
+TEST(CustomOptions, MessageOptionRepeatedMsgFieldSet) {
+  // This test verifies that repeated fields in custom options can be
+  // given multiple values by repeating the option with a different value.
+  // This test checks repeated message values. Each repeated custom value
+  // appears in a different uninterpreted_option, which will be concatenated
+  // when they are merged into the final option value.
+  DescriptorPool pool;
+
+  FileDescriptorProto file_proto;
+  FileDescriptorProto::descriptor()->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+  protobuf_unittest::TestMessageWithCustomOptions::descriptor()
+    ->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+  // The following represents the definition:
+  //
+  //   import "google/protobuf/unittest_custom_options.proto"
+  //   package protobuf_unittest;
+  //   message Foo {
+  //     option (complex_opt2).barney = {waldo: 1};
+  //     option (complex_opt2).barney = {waldo: 10};
+  //     option (complex_opt2).barney = {waldo: 100};
+  //   }
+  ASSERT_TRUE(TextFormat::ParseFromString(
+    "name: \"custom_options_import.proto\" "
+    "package: \"protobuf_unittest\" "
+    "dependency: \"google/protobuf/unittest_custom_options.proto\" "
+    "message_type { "
+    "  name: \"Foo\" "
+    "  options { "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt2\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"barney\" "
+    "        is_extension: false "
+    "      } "
+    "      aggregate_value: \"waldo: 1\" "
+    "    } "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt2\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"barney\" "
+    "        is_extension: false "
+    "      } "
+    "      aggregate_value: \"waldo: 10\" "
+    "    } "
+    "    uninterpreted_option { "
+    "      name { "
+    "        name_part: \"complex_opt2\" "
+    "        is_extension: true "
+    "      } "
+    "      name { "
+    "        name_part: \"barney\" "
+    "        is_extension: false "
+    "      } "
+    "      aggregate_value: \"waldo: 100\" "
+    "    } "
+    "  } "
+    "}",
+    &file_proto));
+
+  const FileDescriptor* file = pool.BuildFile(file_proto);
+  ASSERT_TRUE(file != NULL);
+  ASSERT_EQ(1, file->message_type_count());
+
+  const MessageOptions& options = file->message_type(0)->options();
+  EXPECT_EQ(3, options.GetExtension(
+      protobuf_unittest::complex_opt2).barney_size());
+  EXPECT_EQ(1,options.GetExtension(
+      protobuf_unittest::complex_opt2).barney(0).waldo());
+  EXPECT_EQ(10, options.GetExtension(
+      protobuf_unittest::complex_opt2).barney(1).waldo());
+  EXPECT_EQ(100, options.GetExtension(
+      protobuf_unittest::complex_opt2).barney(2).waldo());
+}
+
 // Check that aggregate options were parsed and saved correctly in
 // the appropriate descriptors.
 TEST(CustomOptions, AggregateOptions) {
@@ -2429,6 +2834,27 @@ TEST(CustomOptions, AggregateOptions) {
             method->options().GetExtension(protobuf_unittest::methodopt).s());
 }
 
+TEST(CustomOptions, UnusedImportWarning) {
+  DescriptorPool pool;
+
+  FileDescriptorProto file_proto;
+  FileDescriptorProto::descriptor()->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+  protobuf_unittest::TestMessageWithCustomOptions::descriptor()
+      ->file()->CopyTo(&file_proto);
+  ASSERT_TRUE(pool.BuildFile(file_proto) != NULL);
+
+
+  pool.AddUnusedImportTrackFile("custom_options_import.proto");
+  ASSERT_TRUE(TextFormat::ParseFromString(
+    "name: \"custom_options_import.proto\" "
+    "package: \"protobuf_unittest\" "
+    "dependency: \"google/protobuf/unittest_custom_options.proto\" ",
+    &file_proto));
+  pool.BuildFile(file_proto);
+}
+
 // ===================================================================
 
 // The tests below trigger every unique call to AddError() in descriptor.cc,
@@ -2442,6 +2868,7 @@ class MockErrorCollector : public DescriptorPool::ErrorCollector {
   ~MockErrorCollector() {}
 
   string text_;
+  string warning_text_;
 
   // implements ErrorCollector ---------------------------------------
   void AddError(const string& filename,
@@ -2465,6 +2892,29 @@ class MockErrorCollector : public DescriptorPool::ErrorCollector {
       &text_, "$0: $1: $2: $3\n",
       filename, element_name, location_name, message);
   }
+
+  // implements ErrorCollector ---------------------------------------
+  void AddWarning(const string& filename, const string& element_name,
+                  const Message* descriptor, ErrorLocation location,
+                  const string& message) {
+    const char* location_name = NULL;
+    switch (location) {
+      case NAME         : location_name = "NAME"         ; break;
+      case NUMBER       : location_name = "NUMBER"       ; break;
+      case TYPE         : location_name = "TYPE"         ; break;
+      case EXTENDEE     : location_name = "EXTENDEE"     ; break;
+      case DEFAULT_VALUE: location_name = "DEFAULT_VALUE"; break;
+      case OPTION_NAME  : location_name = "OPTION_NAME"  ; break;
+      case OPTION_VALUE : location_name = "OPTION_VALUE" ; break;
+      case INPUT_TYPE   : location_name = "INPUT_TYPE"   ; break;
+      case OUTPUT_TYPE  : location_name = "OUTPUT_TYPE"  ; break;
+      case OTHER        : location_name = "OTHER"        ; break;
+    }
+
+    strings::SubstituteAndAppend(
+      &warning_text_, "$0: $1: $2: $3\n",
+      filename, element_name, location_name, message);
+  }
 };
 
 class ValidationErrorTest : public testing::Test {
@@ -2491,6 +2941,19 @@ class ValidationErrorTest : public testing::Test {
     EXPECT_EQ(expected_errors, error_collector.text_);
   }
 
+  // Parse file_text as a FileDescriptorProto in text format and add it
+  // to the DescriptorPool.  Expect errors to be produced which match the
+  // given warning text.
+  void BuildFileWithWarnings(const string& file_text,
+                             const string& expected_warnings) {
+    FileDescriptorProto file_proto;
+    ASSERT_TRUE(TextFormat::ParseFromString(file_text, &file_proto));
+
+    MockErrorCollector error_collector;
+    EXPECT_TRUE(pool_.BuildFileCollectingErrors(file_proto, &error_collector));
+    EXPECT_EQ(expected_warnings, error_collector.warning_text_);
+  }
+
   // Builds some already-parsed file in our test pool.
   void BuildFileInTestPool(const FileDescriptor* file) {
     FileDescriptorProto file_proto;
@@ -2744,8 +3207,8 @@ TEST_F(ValidationErrorTest, InvalidDefaults) {
     "          default_value: \"1\" }"
     "}",
 
-    "foo.proto: Foo.foo: DEFAULT_VALUE: Couldn't parse default value.\n"
-    "foo.proto: Foo.bar: DEFAULT_VALUE: Couldn't parse default value.\n"
+    "foo.proto: Foo.foo: DEFAULT_VALUE: Couldn't parse default value \"abc\".\n"
+    "foo.proto: Foo.bar: DEFAULT_VALUE: Couldn't parse default value \"\".\n"
     "foo.proto: Foo.baz: DEFAULT_VALUE: Boolean default must be true or "
       "false.\n"
     "foo.proto: Foo.qux: DEFAULT_VALUE: Messages can't have default values.\n"
@@ -2828,6 +3291,38 @@ TEST_F(ValidationErrorTest, NonExtensionWithExtendee) {
       "non-extension field.\n");
 }
 
+TEST_F(ValidationErrorTest, FieldOneofIndexTooLarge) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  field { name:\"foo\" number:1 label:LABEL_OPTIONAL type:TYPE_INT32 "
+    "          oneof_index: 1 }"
+    "  field { name:\"dummy\" number:2 label:LABEL_OPTIONAL type:TYPE_INT32 "
+    "          oneof_index: 0 }"
+    "  oneof_decl { name:\"bar\" }"
+    "}",
+
+    "foo.proto: Foo.foo: OTHER: FieldDescriptorProto.oneof_index 1 is out of "
+      "range for type \"Foo\".\n");
+}
+
+TEST_F(ValidationErrorTest, FieldOneofIndexNegative) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  field { name:\"foo\" number:1 label:LABEL_OPTIONAL type:TYPE_INT32 "
+    "          oneof_index: -1 }"
+    "  field { name:\"dummy\" number:2 label:LABEL_OPTIONAL type:TYPE_INT32 "
+    "          oneof_index: 0 }"
+    "  oneof_decl { name:\"bar\" }"
+    "}",
+
+    "foo.proto: Foo.foo: OTHER: FieldDescriptorProto.oneof_index -1 is out of "
+      "range for type \"Foo\".\n");
+}
+
 TEST_F(ValidationErrorTest, FieldNumberConflict) {
   BuildFileWithErrors(
     "name: \"foo.proto\" "
@@ -2988,6 +3483,28 @@ TEST_F(ValidationErrorTest, NotAnExtensionNumber) {
       "number.\n");
 }
 
+TEST_F(ValidationErrorTest, RequiredExtension) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Bar\""
+    "  extension_range { start: 1000 end: 10000 }"
+    "}"
+    "message_type {"
+    "  name: \"Foo\""
+    "  extension {"
+    "    name:\"foo\""
+    "    number:1000"
+    "    label:LABEL_REQUIRED"
+    "    type:TYPE_INT32"
+    "    extendee: \"Bar\""
+    "  }"
+    "}",
+
+    "foo.proto: Foo.foo: TYPE: Message extensions cannot have required "
+    "fields.\n");
+}
+
 TEST_F(ValidationErrorTest, UndefinedFieldType) {
   BuildFileWithErrors(
     "name: \"foo.proto\" "
@@ -2999,6 +3516,36 @@ TEST_F(ValidationErrorTest, UndefinedFieldType) {
     "foo.proto: Foo.foo: TYPE: \"Bar\" is not defined.\n");
 }
 
+TEST_F(ValidationErrorTest, UndefinedFieldTypeWithDefault) {
+  // See b/12533582. Previously this failed because the default value was not
+  // accepted by the parser, which assumed an enum type, leading to an unclear
+  // error message. We want this input to yield a validation error instead,
+  // since the unknown type is the primary problem.
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  field { name:\"foo\" number:1 label:LABEL_OPTIONAL type_name:\"int\" "
+    "          default_value:\"1\" }"
+    "}",
+
+    "foo.proto: Foo.foo: TYPE: \"int\" is not defined.\n");
+}
+
+TEST_F(ValidationErrorTest, UndefinedNestedFieldType) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  nested_type { name:\"Baz\" }"
+    "  field { name:\"foo\" number:1"
+    "          label:LABEL_OPTIONAL"
+    "          type_name:\"Foo.Baz.Bar\" }"
+    "}",
+
+    "foo.proto: Foo.foo: TYPE: \"Foo.Baz.Bar\" is not defined.\n");
+}
+
 TEST_F(ValidationErrorTest, FieldTypeDefinedInUndeclaredDependency) {
   BuildFile(
     "name: \"bar.proto\" "
@@ -3174,7 +3721,8 @@ TEST_F(ValidationErrorTest,
 
 
 TEST_F(ValidationErrorTest, SearchMostLocalFirst) {
-  // The following should produce an error that Bar.Baz is not defined:
+  // The following should produce an error that Bar.Baz is resolved but
+  // not defined:
   //   message Bar { message Baz {} }
   //   message Foo {
   //     message Bar {
@@ -3200,7 +3748,10 @@ TEST_F(ValidationErrorTest, SearchMostLocalFirst) {
     "          type_name:\"Bar.Baz\" }"
     "}",
 
-    "foo.proto: Foo.baz: TYPE: \"Bar.Baz\" is not defined.\n");
+    "foo.proto: Foo.baz: TYPE: \"Bar.Baz\" is resolved to \"Foo.Bar.Baz\","
+    " which is not defined. The innermost scope is searched first in name "
+    "resolution. Consider using a leading '.'(i.e., \".Bar.Baz\") to start "
+    "from the outermost scope.\n");
 }
 
 TEST_F(ValidationErrorTest, SearchMostLocalFirst2) {
@@ -3342,6 +3893,20 @@ TEST_F(ValidationErrorTest, BadEnumDefaultValue) {
       "\"NO_SUCH_VALUE\".\n");
 }
 
+TEST_F(ValidationErrorTest, EnumDefaultValueIsInteger) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "enum_type { name: \"Bar\" value { name:\"DUMMY\" number:0 } } "
+    "message_type {"
+    "  name: \"Foo\""
+    "  field { name:\"foo\" number:1 label:LABEL_OPTIONAL type_name:\"Bar\""
+    "          default_value:\"0\" }"
+    "}",
+
+    "foo.proto: Foo.foo: DEFAULT_VALUE: Default value for an enum field must "
+    "be an identifier.\n");
+}
+
 TEST_F(ValidationErrorTest, PrimitiveWithTypeName) {
   BuildFileWithErrors(
     "name: \"foo.proto\" "
@@ -3366,6 +3931,31 @@ TEST_F(ValidationErrorTest, NonPrimitiveWithoutTypeName) {
       "type_name.\n");
 }
 
+TEST_F(ValidationErrorTest, OneofWithNoFields) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  oneof_decl { name:\"bar\" }"
+    "}",
+
+    "foo.proto: Foo.bar: NAME: Oneof must have at least one field.\n");
+}
+
+TEST_F(ValidationErrorTest, OneofLabelMismatch) {
+  BuildFileWithErrors(
+    "name: \"foo.proto\" "
+    "message_type {"
+    "  name: \"Foo\""
+    "  field { name:\"foo\" number:1 label:LABEL_REPEATED type:TYPE_INT32 "
+    "          oneof_index:0 }"
+    "  oneof_decl { name:\"bar\" }"
+    "}",
+
+    "foo.proto: Foo.foo: NAME: Fields of oneofs must themselves have label "
+      "LABEL_OPTIONAL.\n");
+}
+
 TEST_F(ValidationErrorTest, InputTypeNotDefined) {
   BuildFileWithErrors(
     "name: \"foo.proto\" "
@@ -3527,20 +4117,85 @@ TEST_F(ValidationErrorTest, InvalidOptionName) {
     "reserved name \"uninterpreted_option\".\n");
 }
 
-TEST_F(ValidationErrorTest, RepeatedOption) {
+TEST_F(ValidationErrorTest, RepeatedMessageOption) {
   BuildDescriptorMessagesInTestPool();
 
   BuildFileWithErrors(
     "name: \"foo.proto\" "
     "dependency: \"google/protobuf/descriptor.proto\" "
-    "extension { name: \"foo\" number: 7672757 label: LABEL_REPEATED "
-    "            type: TYPE_FLOAT extendee: \"google.protobuf.FileOptions\" }"
-    "options { uninterpreted_option { name { name_part: \"foo\" "
+    "message_type: { name: \"Bar\" field: { "
+    "  name: \"foo\" number: 1 label: LABEL_OPTIONAL type: TYPE_INT32 } "
+    "} "
+    "extension { name: \"bar\" number: 7672757 label: LABEL_REPEATED "
+    "            type: TYPE_MESSAGE type_name: \"Bar\" "
+    "            extendee: \"google.protobuf.FileOptions\" }"
+    "options { uninterpreted_option { name { name_part: \"bar\" "
     "                                        is_extension: true } "
-    "                                 double_value: 1.2 } }",
+    "                                 name { name_part: \"foo\" "
+    "                                        is_extension: false } "
+    "                                 positive_int_value: 1 } }",
 
-    "foo.proto: foo.proto: OPTION_NAME: Option field \"(foo)\" is repeated. "
-    "Repeated options are not supported.\n");
+    "foo.proto: foo.proto: OPTION_NAME: Option field \"(bar)\" is a "
+    "repeated message. Repeated message options must be initialized "
+    "using an aggregate value.\n");
+}
+
+TEST_F(ValidationErrorTest, ResolveUndefinedOption) {
+  // The following should produce an eror that baz.bar is resolved but not
+  // defined.
+  // foo.proto:
+  //   package baz
+  //   import google/protobuf/descriptor.proto
+  //   message Bar { optional int32 foo = 1; }
+  //   extend FileOptions { optional Bar bar = 7672757; }
+  //
+  // qux.proto:
+  //   package qux.baz
+  //   option (baz.bar).foo = 1;
+  //
+  // Although "baz.bar" is already defined, the lookup code will try
+  // "qux.baz.bar", since it's the match from the innermost scope, which will
+  // cause a symbol not defined error.
+  BuildDescriptorMessagesInTestPool();
+
+  BuildFile(
+    "name: \"foo.proto\" "
+    "package: \"baz\" "
+    "dependency: \"google/protobuf/descriptor.proto\" "
+    "message_type: { name: \"Bar\" field: { "
+    "  name: \"foo\" number: 1 label: LABEL_OPTIONAL type: TYPE_INT32 } "
+    "} "
+    "extension { name: \"bar\" number: 7672757 label: LABEL_OPTIONAL "
+    "            type: TYPE_MESSAGE type_name: \"Bar\" "
+    "            extendee: \"google.protobuf.FileOptions\" }");
+
+  BuildFileWithErrors(
+    "name: \"qux.proto\" "
+    "package: \"qux.baz\" "
+    "options { uninterpreted_option { name { name_part: \"baz.bar\" "
+    "                                        is_extension: true } "
+    "                                 name { name_part: \"foo\" "
+    "                                        is_extension: false } "
+    "                                 positive_int_value: 1 } }",
+
+    "qux.proto: qux.proto: OPTION_NAME: Option \"(baz.bar)\" is resolved to "
+    "\"(qux.baz.bar)\","
+    " which is not defined. The innermost scope is searched first in name "
+    "resolution. Consider using a leading '.'(i.e., \"(.baz.bar)\") to start "
+    "from the outermost scope.\n");
+}
+
+TEST_F(ValidationErrorTest, UnknownOption) {
+  BuildFileWithErrors(
+    "name: \"qux.proto\" "
+    "package: \"qux.baz\" "
+    "options { uninterpreted_option { name { name_part: \"baaz.bar\" "
+    "                                        is_extension: true } "
+    "                                 name { name_part: \"foo\" "
+    "                                        is_extension: false } "
+    "                                 positive_int_value: 1 } }",
+
+    "qux.proto: qux.proto: OPTION_NAME: Option \"(baaz.bar)\" unknown.\n");
 }
 
 TEST_F(ValidationErrorTest, CustomOptionConflictingFieldNumber) {
@@ -3813,6 +4468,25 @@ TEST_F(ValidationErrorTest, StringOptionValueIsNotString) {
     "string option \"foo\".\n");
 }
 
+TEST_F(ValidationErrorTest, DuplicateExtensionFieldNumber) {
+  BuildDescriptorMessagesInTestPool();
+
+  BuildFile(
+      "name: \"foo.proto\" "
+      "dependency: \"google/protobuf/descriptor.proto\" "
+      "extension { name: \"option1\" number: 1000 label: LABEL_OPTIONAL "
+      "            type: TYPE_INT32 extendee: \"google.protobuf.FileOptions\" }");
+
+  BuildFileWithWarnings(
+      "name: \"bar.proto\" "
+      "dependency: \"google/protobuf/descriptor.proto\" "
+      "extension { name: \"option2\" number: 1000 label: LABEL_OPTIONAL "
+      "            type: TYPE_INT32 extendee: \"google.protobuf.FileOptions\" }",
+      "bar.proto: option2: NUMBER: Extension number 1000 has already been used "
+      "in \"google.protobuf.FileOptions\" by extension \"option1\" defined in "
+      "foo.proto.\n");
+}
+
 // Helper function for tests that check for aggregate value parsing
 // errors.  The "value" argument is embedded inside the
 // "uninterpreted_option" portion of the result.
@@ -3998,7 +4672,6 @@ TEST_F(ValidationErrorTest, DisallowEnumAlias) {
     "  name: \"Bar\""
     "  value { name:\"ENUM_A\" number:0 }"
     "  value { name:\"ENUM_B\" number:0 }"
-    "  options { allow_alias: false }"
     "}",
     "foo.proto: Bar: NUMBER: "
     "\"ENUM_B\" uses the same enum value as \"ENUM_A\". "
@@ -4006,6 +4679,64 @@ TEST_F(ValidationErrorTest, DisallowEnumAlias) {
     "definition.\n");
 }
 
+TEST_F(ValidationErrorTest, AllowEnumAlias) {
+  BuildFile(
+    "name: \"foo.proto\" "
+    "enum_type {"
+    "  name: \"Bar\""
+    "  value { name:\"ENUM_A\" number:0 }"
+    "  value { name:\"ENUM_B\" number:0 }"
+    "  options { allow_alias: true }"
+    "}");
+}
+
+TEST_F(ValidationErrorTest, UnusedImportWarning) {
+
+  pool_.AddUnusedImportTrackFile("bar.proto");
+  BuildFile(
+    "name: \"bar.proto\" "
+    "message_type { name: \"Bar\" }");
+
+  pool_.AddUnusedImportTrackFile("base.proto");
+  BuildFile(
+    "name: \"base.proto\" "
+    "message_type { name: \"Base\" }");
+
+  pool_.AddUnusedImportTrackFile("baz.proto");
+  BuildFile(
+    "name: \"baz.proto\" "
+    "message_type { name: \"Baz\" }");
+
+  pool_.AddUnusedImportTrackFile("public.proto");
+  BuildFile(
+    "name: \"public.proto\" "
+    "dependency: \"bar.proto\""
+    "public_dependency: 0");
+
+  // // forward.proto
+  // import "base.proto"       // No warning: Base message is used.
+  // import "bar.proto"        // Will log a warning.
+  // import public "baz.proto" // No warning: Do not track import public.
+  // import "public.proto"     // No warning: public.proto has import public.
+  // message Forward {
+  //   optional Base base = 1;
+  // }
+  //
+  pool_.AddUnusedImportTrackFile("forward.proto");
+  BuildFile(
+    "name: \"forward.proto\""
+    "dependency: \"base.proto\""
+    "dependency: \"bar.proto\""
+    "dependency: \"baz.proto\""
+    "dependency: \"public.proto\""
+    "public_dependency: 2 "
+    "message_type {"
+    "  name: \"Forward\""
+    "  field { name:\"base\" number:1 label:LABEL_OPTIONAL type_name:\"Base\" }"
+    "}");
+}
+
+
 // ===================================================================
 // DescriptorDatabase
 
@@ -4328,6 +5059,10 @@ TEST_F(DatabaseBackedPoolTest, UnittestProto) {
 
   EXPECT_EQ(original_file_proto.DebugString(),
             file_from_database_proto.DebugString());
+
+  // Also verify that CopyTo() did not omit any information.
+  EXPECT_EQ(original_file->DebugString(),
+            file_from_database->DebugString());
 }
 
 TEST_F(DatabaseBackedPoolTest, DoesntRetryDbUnnecessarily) {
@@ -4396,15 +5131,93 @@ TEST_F(DatabaseBackedPoolTest, DoesntReloadFilesUncesessarily) {
   EXPECT_EQ("", error_collector.text_);
 }
 
+// DescriptorDatabase that attempts to induce exponentially-bad performance
+// in DescriptorPool. For every positive N, the database contains a file
+// fileN.proto, which defines a message MessageN, which contains fields of
+// type MessageK for all K in [0,N). Message0 is not defined anywhere
+// (file0.proto exists, but is empty), so every other file and message type
+// will fail to build.
+//
+// If the DescriptorPool is not careful to memoize errors, an attempt to
+// build a descriptor for MessageN can require O(2^N) time.
+class ExponentialErrorDatabase : public DescriptorDatabase {
+ public:
+  ExponentialErrorDatabase() {}
+  ~ExponentialErrorDatabase() {}
+
+  // implements DescriptorDatabase ---------------------------------
+  bool FindFileByName(const string& filename,
+                      FileDescriptorProto* output) {
+    int file_num = -1;
+    FullMatch(filename, "file", ".proto", &file_num);
+    if (file_num > -1) {
+      return PopulateFile(file_num, output);
+    } else {
+      return false;
+    }
+  }
+  bool FindFileContainingSymbol(const string& symbol_name,
+                                FileDescriptorProto* output) {
+    int file_num = -1;
+    FullMatch(symbol_name, "Message", "", &file_num);
+    if (file_num > 0) {
+      return PopulateFile(file_num, output);
+    } else {
+      return false;
+    }
+  }
+  bool FindFileContainingExtension(const string& containing_type,
+                                   int field_number,
+                                   FileDescriptorProto* output) {
+    return false;
+  }
+
+ private:
+  void FullMatch(const string& name,
+                 const string& begin_with,
+                 const string& end_with,
+                 int* file_num) {
+    int begin_size = begin_with.size();
+    int end_size = end_with.size();
+    if (name.substr(0, begin_size) != begin_with ||
+        name.substr(name.size()- end_size, end_size) != end_with) {
+      return;
+    }
+    safe_strto32(name.substr(begin_size, name.size() - end_size - begin_size),
+                 file_num);
+  }
+
+  bool PopulateFile(int file_num, FileDescriptorProto* output) {
+    using strings::Substitute;
+    GOOGLE_CHECK_GE(file_num, 0);
+    output->Clear();
+    output->set_name(Substitute("file$0.proto", file_num));
+    // file0.proto doesn't define Message0
+    if (file_num > 0) {
+      DescriptorProto* message = output->add_message_type();
+      message->set_name(Substitute("Message$0", file_num));
+      for (int i = 0; i < file_num; ++i) {
+        output->add_dependency(Substitute("file$0.proto", i));
+        FieldDescriptorProto* field = message->add_field();
+        field->set_name(Substitute("field$0", i));
+        field->set_number(i);
+        field->set_label(FieldDescriptorProto::LABEL_OPTIONAL);
+        field->set_type(FieldDescriptorProto::TYPE_MESSAGE);
+        field->set_type_name(Substitute("Message$0", i));
+      }
+    }
+    return true;
+  }
+};
+
 TEST_F(DatabaseBackedPoolTest, DoesntReloadKnownBadFiles) {
-  ErrorDescriptorDatabase error_database;
-  MockErrorCollector error_collector;
-  DescriptorPool pool(&error_database, &error_collector);
+  ExponentialErrorDatabase error_database;
+  DescriptorPool pool(&error_database);
 
-  EXPECT_TRUE(pool.FindFileByName("error.proto") == NULL);
-  error_collector.text_.clear();
-  EXPECT_TRUE(pool.FindFileByName("error.proto") == NULL);
-  EXPECT_EQ("", error_collector.text_);
+  GOOGLE_LOG(INFO) << "A timeout in this test probably indicates a real bug.";
+
+  EXPECT_TRUE(pool.FindFileByName("file40.proto") == NULL);
+  EXPECT_TRUE(pool.FindMessageTypeByName("Message40") == NULL);
 }
 
 TEST_F(DatabaseBackedPoolTest, DoesntFallbackOnWrongType) {
@@ -4489,6 +5302,17 @@ const char *const kSourceLocationTestInput =
   "  rpc Method(A) returns (A.B);\n"
   // Put an empty line here to make the source location range match.
   "\n"
+  "}\n"
+  "message MessageWithExtensions {\n"
+  "  extensions 1000 to max;\n"
+  "}\n"
+  "extend MessageWithExtensions {\n"
+  "  optional int32 int32_extension = 1001;\n"
+  "}\n"
+  "message C {\n"
+  "  extend MessageWithExtensions {\n"
+  "    optional C message_extension = 1002;\n"
+  "  }\n"
   "}\n";
 
 class SourceLocationTest : public testing::Test {
@@ -4550,6 +5374,27 @@ TEST_F(SourceLocationTest, GetSourceLocation) {
 
 }
 
+TEST_F(SourceLocationTest, ExtensionSourceLocation) {
+  SourceLocation loc;
+
+  const FileDescriptor *file_desc =
+      GOOGLE_CHECK_NOTNULL(pool_.FindFileByName("/test/test.proto"));
+
+  const FieldDescriptor *int32_extension_desc =
+      file_desc->FindExtensionByName("int32_extension");
+  EXPECT_TRUE(int32_extension_desc->GetSourceLocation(&loc));
+  EXPECT_EQ("21:3-21:41", PrintSourceLocation(loc));
+
+  const Descriptor *c_desc = file_desc->FindMessageTypeByName("C");
+  EXPECT_TRUE(c_desc->GetSourceLocation(&loc));
+  EXPECT_EQ("23:1-27:2", PrintSourceLocation(loc));
+
+  const FieldDescriptor *message_extension_desc =
+      c_desc->FindExtensionByName("message_extension");
+  EXPECT_TRUE(message_extension_desc->GetSourceLocation(&loc));
+  EXPECT_EQ("25:5-25:41", PrintSourceLocation(loc));
+}
+
 // Missing SourceCodeInfo doesn't cause crash:
 TEST_F(SourceLocationTest, GetSourceLocation_MissingSourceCodeInfo) {
   SourceLocation loc;