What is the expected response for a getmemorypool RPC call to a standard client, when calling it with data field? I'm mainly interested in such factors as:

• Will the call return true if a sent block is not at the end of a block chain (for example, creates a fork or otherwise invalidates some other blocks)?
• Will the call return false if the client is BitcoinQT, not bitcoind?
• Will the call return true if the same block is submitted more than once?
• Will the call return true if the block does not contain all transactions sent earlier, or contains some transactions that the client does not know about?
• Are there any other specific cases one should know about when coding for this call?