fix amounts in overflow bug description

[MBaum21]

easy changes:
INT64_MAX is 9223372036854775807 (2**63-1)
INT64_MIN is -9223372036854775808 (-2**63)

other changes:
For whatever reason, post # 1 in bitcointalk topic 822 contains a different output amount than post # 3
post #1: 92233720368.54277039 (0x7ffffffffff863af)
post #3: 92233720368.54275808 (0x7ffffffffff85ee0)
I'm assuming post # 3 ist right, because it's 2**63-500000, and the sum of outputs is a round number: -0.01 BTC (minus 1 million sats). (calculation: 9223372036854275808*2 - 2**64 = -1000000)

[murchandamus]

I spent some time looking into this. I found the raw transaction from the value overflow incident:

0100000001395d705a36b122c01c9be97f8c69994c03bb8a0531990411ce7ac78f34e87f23000000008b483045022100db8ccad098467a80bdb9ae16fc a82aa4214a66c1ee24b62b696073e7e4f6879302205ad02d53231be18c5d6a77ffdb39476a5b5da4be70f0acc6794b181f4e38027ca841046b5d97aeed 2979207f4ca7d9e75cdebf9ebb2a47d0b715370645f6845edfa7adfb0627ad7bda601ad2d129ebf037c5750841e9ba64ab199c4cb8280a95335d96ffff ffff02af63f8ffffffff7f1976a91490e8d5ba1c2a301824b18d383dead728b13ea7b788acaf63f8ffffffff7f1976a9142c72c4b5e0cbf9b6435f2cec 9df8668c5075121588ac00000000

The two output amounts were 0x7ffffffffff863af which corresponds to 9,223,372,036,854,277,039 sats and are in the range of int64.

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Edit:

I notice that a second raw transaction is posted later in the thread which does appear to have the value of 9,223,372,036,854,275,808:

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

I’ll have to look further into this.

[murchandamus]

Okay, yeah, you are right. The two outputs sum to –0.01 ₿ which then explains why the coinbase collects 50 ₿ new coins and 0.5 ₿ –(–0.01 ₿) = 50.51 ₿ from the transaction.

I will look over the text, I think we might need to amend the text a little further.

[murchandamus]

Suggested change

	starting with -9,223,372,036,854,775,808 sats. This meant it looked like the
	transaction spent a total of -0.01 BTC (negative 0.01 BTC). This
	starting with -9,223,372,036,854,775,808 sats. This meant it looked like the
	transaction outputs summed to a total of -0.01 BTC (negative 0.01 BTC). This

[murchandamus]

Oh, I just realized that thread is from last month. Is that you digging up the actual raw transaction? :)

[MBaum21]

Thanks for your response @murchandamus :)

Nice investigation by ercewubam in that thread from march. No, that's not me.
Good to have the amount confirmed, i.e. 92233720368.54275808 ₿.

I will look over the text, I think we might need to amend the text a little further.

Is there still something to amend? :)

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Edit:

we could change the commit message to this:

easy changes:
INT64_MAX is 9223372036854775807 (2**63-1)
INT64_MIN is -9223372036854775808 (-2**63)

post # 1 in bitcointalk topic 822 ( https://bitcointalk.org/index.php?topic=822.0 )
contains a different output amount than post # 3
post # 1: 92233720368.54277039 (0x7ffffffffff863af)
post # 3: 92233720368.54275808 (0x7ffffffffff85ee0)
Turns out post # 3 ist right, see this thread:
https://bitcointalk.org/index.php?topic=5488487.msg63795653#msg63795653
That also makes sense, because the amount in post # 3 is 2**63-500000,
and the sum of outputs is minus 1 million sats (-0.01 BTC).
(9223372036854275808*2 - 2**64 = -1000000)

[murchandamus]

I think I have rediscovered the minutiae of this situation.

• There were two 92 billion BTC outputs, each individually 500,000 sats below INT64_MAX
• In sum, these two outputs add up to -1,000,000 sats or -0.01 BTC due to an integer overflow when they were summed up
• This resulted in a transaction fee of 0.51 BTC, from the input with 0.5 BTC minus the -0.01 BTC (i.e., -(-0.01) = + 0.01) from the summed outputs

I’ve added half a sentence that would have helped me catch on faster, and otherwise concur with the proposed changes by @MBaum21.

[bitschmidty]

ACK, thank you @MBaum21 and @murchandamus