Check access to included schema list

Summary: Avoid out-of-bounds access when a dependency has schema disabled.

Reviewed By: createdbysk

Differential Revision: D70001932

fbshipit-source-id: 33f5ef434416a5fd76571fdbf618816da8bac339

thrift/lib/cpp2/gen/module_constants_cpp.cpp

@@ -25,7 +25,8 @@ ::std::string_view readSchema(::std::string_view (*access)()) {
 ::std::string_view readSchemaInclude(
     ::folly::Range<const ::std::string_view*> (*access)(),
     ::std::size_t index) {
-  return access()[index];
+  auto range = access();
+  return index < range.size() ? range[index] : "";
 }
 
 } // namespace apache::thrift::detail::mc

thrift/test/SchemaTest.cpp

@@ -92,7 +92,7 @@ TEST(SchemaTest, linked) {
 TEST(SchemaTest, static_schema) {
   auto static_schema = SchemaRegistry::mergeSchemas(
       facebook::thrift::test::schema::schema_constants::
-          _fbthrift_schema_fba4d3dcfb7c979a_includes());
+          _fbthrift_schema_542ebcbee39d65d1_includes());
   const type::Program* static_program = nullptr;
   for (const auto& program : *static_schema.programs()) {
     if (program.path() == "thrift/test/schema.thrift") {
@@ -115,7 +115,7 @@ TEST(SchemaTest, static_schema) {
 
 TEST(SchemaTest, merged_schema_add_after_access) {
   auto data = facebook::thrift::test::schema::schema_constants::
-      _fbthrift_schema_fba4d3dcfb7c979a();
+      _fbthrift_schema_542ebcbee39d65d1();
 
   BaseSchemaRegistry base;
   SchemaRegistry registry(base);

thrift/test/schema.thrift

@@ -16,6 +16,7 @@
 
 include "thrift/annotation/scope.thrift"
 include "thrift/annotation/cpp.thrift"
+include "thrift/lib/thrift/patch.thrift" // @nolint used to test depending on this file
 
 package "facebook.com/thrift/test/schema"