Set dropped column family before persisting in the manifest

Author: igorcanadi

db/db_impl.cc

@@ -3098,10 +3098,10 @@ Status DBImpl::DropColumnFamily(ColumnFamilyHandle* column_family) {
     s = Status::InvalidArgument("Column family already dropped!\n");
   }
   if (s.ok()) {
+    cfd->SetDropped();
     s = versions_->LogAndApply(cfd, &edit, &mutex_);
   }
   if (s.ok()) {
-    cfd->SetDropped();
     // DB is holding one reference to each column family when it's alive,
     // need to drop it now
     if (cfd->Unref()) {

db/version_set.cc

@@ -1489,8 +1489,9 @@ Status VersionSet::LogAndApply(ColumnFamilyData* column_family_data,
                                bool new_descriptor_log) {
   mu->AssertHeld();
 
-  if (column_family_data->IsDropped()) {
-    // no need to write anything to the manifest
+  if (column_family_data->IsDropped() && !edit->is_column_family_drop_) {
+    // if column family is dropped no need to write anything to the manifest
+    // (unless, of course, thit is the drop column family write)
     return Status::OK();
   }