block reward that can never be spent

[arulbero]

This article claims that the block immediately following every halving can never be spent.
(I knew that only genesis block reward cannot be spent)

Is that true?

[gmaxwell]

This article claims that the block immediately following every halving can never be spent.
(I knew that only genesis block reward cannot be spent)

Is that true?

No, it's not true.

[cr1776]

This article claims that the block immediately following every halving can never be spent.
(I knew that only genesis block reward cannot be spent)

Is that true?

Take a look at
http://blockr.io/block/info/210000
http://blockr.io/block/info/210001

vs
http://blockr.io/block/info/420000
http://blockr.io/block/info/420001 - it appears this has not been spent yet (but not because it can not)

It seems like an odd claim that they are making, given the blocks above.

[piotr_n]

(I knew that only genesis block reward cannot be spent)

Not only.
I believe there are two cases in the block chain where coinbase TX had the same ID as another one before it.
It is not possible anymore, but it used to be possible.
The two rewards became unspendable when the nodes' implementation switched to LevelDB (that replaced BerkeleyDB for storing UTXO set).
They were spendable before, but now such is the "consensus".

But I don't know anything about "[reward from] the block immediately following every halving can never be spent"
That would be something new, would have to be some implementation bug.
But more likely it's just fake news

[ArcCsch]

The genesis block, mined by Satoshi Nakamoto, cannot be spent, this was probably intentional since only He had the software to mine it, and getting coins for it would be a premine. The only other case of an unspendable reward, was, as others have mentioned, repeated coinbase transactions. There is, however, another subtle point; the block reward claimed by the miner cannot be more than the expected amount of new coins plus the fees, but it can be less, so miners can underpay themselves (this has actually been done).

However, nothing prevents the reward right after a halving from being spent.

[chrisvl]

This article claims that the block immediately following every halving can never be spent.
(I knew that only genesis block reward cannot be spent)

Is that true?

The genesis block reward can't be spend, because was hard_coded ^simple satoshi don't add the coinbase transaction into the global database,so each block reward after genesis block can be spend