VersionSet::AddLiveFiles() to assert current version is included.

Summary: Add an extra assert to make sure current version is included in VersionSet::AddLiveFiles().

Test Plan: make all check

Reviewers: yhchiang, rven, igor

Reviewed By: igor

Subscribers: dhruba, hermanlee4, leveldb

Differential Revision: https://reviews.facebook.net/D30819

db/version_set.cc

@@ -2636,16 +2636,21 @@ void VersionSet::AddLiveFiles(std::vector<FileDescriptor>* live_list) {
   live_list->reserve(live_list->size() + static_cast<size_t>(total_files));
 
   for (auto cfd : *column_family_set_) {
+    auto* current = cfd->current();
+    bool found_current = false;
     Version* dummy_versions = cfd->dummy_versions();
     for (Version* v = dummy_versions->next_; v != dummy_versions;
          v = v->next_) {
-      const auto* vstorage = v->storage_info();
-      for (int level = 0; level < vstorage->num_levels(); level++) {
-        for (const auto& f : vstorage->LevelFiles(level)) {
-          live_list->push_back(f->fd);
-        }
+      v->AddLiveFiles(live_list);
+      if (v == current) {
+        found_current = true;
       }
     }
+    if (!found_current && current != nullptr) {
+      // Should never happen unless it is a bug.
+      assert(false);
+      current->AddLiveFiles(live_list);
+    }
   }
 }