Description
When a SolrCore for a particular index is created for the first time, it's added to the SolrCores#createdCores map. However, this map doesn't get updated when this core is reloaded, leading to the first SolrCore being leaked.
Taking a look at how createdCores is used, it seems like it doesn't serve any purpose (its only read is in SolrCores#getAllCoreNames, which includes entries from SolrCores.cores anyway), so I'm proposing a patch to remove the createdCores map completely. However, if someone else knows that createdCores exist for a reason, I'll be happy to change the fix to updating the createdCores map when reload is called.