Silently ignore multiple registration of files

src/cpp_entity_index.cpp

@@ -7,6 +7,7 @@
 #include <cppast/detail/assert.hpp>
 #include <cppast/cpp_entity.hpp>
 #include <cppast/cpp_entity_kind.hpp>
+#include <cppast/cpp_file.hpp>
 
 using namespace cppast;
 
@@ -33,6 +34,13 @@ void cpp_entity_index::register_definition(cpp_entity_id
     }
 }
 
+bool cpp_entity_index::register_file(cpp_entity_id                         id,
+                                     type_safe::object_ref<const cpp_file> file) const
+{
+    std::lock_guard<std::mutex> lock(mutex_);
+    return map_.emplace(std::move(id), value(file, true)).second;
+}
+
 void cpp_entity_index::register_forward_declaration(
     cpp_entity_id id, type_safe::object_ref<const cpp_entity> entity) const
 {

src/libclang/libclang_parser.cpp

@@ -399,7 +399,7 @@ std::unique_ptr<cpp_file> libclang_parser::do_parse(const cpp_entity_index& idx,
     auto              macro_iter   = preprocessed.macros.begin();
     auto              include_iter = preprocessed.includes.begin();
 
-    // convert entity hierachies
+    // convert entity hierarchies
     detail::parse_context context{tu.get(), file, type_safe::ref(logger()), type_safe::ref(idx),
                                   detail::comment_context(preprocessed.comments)};
     detail::visit_tu(tu, path.c_str(), [&](const CXCursor& cur) {
@@ -444,5 +444,5 @@ std::unique_ptr<cpp_file> libclang_parser::do_parse(const cpp_entity_index& idx,
 catch (detail::parse_error& ex)
 {
     logger().log("libclang parser", ex.get_diagnostic());
-    return cpp_file::builder(path).finish(idx);
+    return nullptr;
 }