Add simple test for reusing collection names

It is possible that users want to "ignore" a certain collection when
reading files. It should then still be possible to add a new collection
with the same name to the event that has been created without breaking
anything.

tests/read_frame.h

@@ -1,6 +1,7 @@
 #ifndef PODIO_TESTS_READ_FRAME_H // NOLINT(llvm-header-guard): folder structure not suitable
 #define PODIO_TESTS_READ_FRAME_H // NOLINT(llvm-header-guard): folder structure not suitable
 
+#include "datamodel/ExampleHitCollection.h"
 #include "datamodel/ExampleWithInterfaceRelationCollection.h"
 #include "datamodel/ExampleWithVectorMemberCollection.h"
 #include "read_test.h"
@@ -279,7 +280,7 @@ template <typename ReaderT>
 int test_read_frame_limited(ReaderT& reader) {
   const std::vector<std::string> collsToRead = {"mcparticles", "clusters"};
 
-  const auto event = [&]() {
+  auto event = [&]() {
     if constexpr (std::is_same_v<ReaderT, podio::Reader>) {
       return podio::Frame(reader.readFrame("events", 1, collsToRead));
     } else {
@@ -325,6 +326,17 @@ int test_read_frame_limited(ReaderT& reader) {
     return 1;
   }
 
+  const auto& newHits = [&]() -> auto const& {
+    auto mutHits = ExampleHitCollection();
+    mutHits.create();
+    return event.put(std::move(mutHits), "hits");
+  }();
+
+  if (newHits.size() != 1) {
+    std::cerr << "Adding new collection with same name as available from data (but not read) doesn't work" << std::endl;
+    return 1;
+  }
+
   // Check that nothing breaks if we pass in an unavailable collection name
   const auto emptyEvent = [&]() {
     if constexpr (std::is_same_v<ReaderT, podio::Reader>) {