Merge pull request ethereum#824 from jamesray1/patch-1

Add links to issues 90 and 114.

EIPS/eip-150.md

@@ -21,7 +21,7 @@ If `block.number >= FORK_BLKNUM`, then:
 - If SELFDESTRUCT hits a newly created account, it triggers an additional gas cost of 25000 (similar to CALLs)
 - Increase the recommended gas limit target to 5.5 million
 - Define "all but one 64th" of `N` as `N - floor(N / 64)`
-- If a call asks for more gas than the maximum allowed amount (ie. total amount of gas remaining in the parent after subtracting the gas cost of the call and memory expansion), do not return an OOG error; instead, if a call asks for more gas than all but one 64th of the maximum allowed amount, call with all but one 64th of the maximum allowed amount of gas (this is equivalent to a version of #90 plus #114). CREATE only provides all but one 64th of the parent gas to the child call.
+- If a call asks for more gas than the maximum allowed amount (ie. total amount of gas remaining in the parent after subtracting the gas cost of the call and memory expansion), do not return an OOG error; instead, if a call asks for more gas than all but one 64th of the maximum allowed amount, call with all but one 64th of the maximum allowed amount of gas (this is equivalent to a version of EIP-90<sup>[1](https://github.com/ethereum/EIPs/issues/90)</sup> plus EIP-114<sup>[2](https://github.com/ethereum/EIPs/issues/114)</sup>). CREATE only provides all but one 64th of the parent gas to the child call.
 
 That is, substitute:
 
@@ -57,3 +57,8 @@ This EIP aims to be simple, and adds a flat penalty of 300 gas on top of the cos
 The EIP 90 gas mechanic is introduced because without it, all current contracts that make calls would stop working as they use an expression like `msg.gas - 40` to determine how much gas to make a call with, relying on the gas cost of calls being 40. Additionally, EIP 114 is introduced because, given that we are making the cost of a call higher and less predictable, we have an opportunity to do it at no extra cost to currently available guarantees, and so we also achieve the benefit of replacing the call stack depth limit with a "softer" gas-based restriction, thereby eliminating call stack depth attacks as a class of attack that contract developers have to worry about and hence increasing contract programming safety. Note that with the given parameters, the de-facto maximum call stack depth is limited to ~340 (down from ~1024), mitigating the harm caused by any further potential quadratic-complexity DoS attacks that rely on calls.
 
 The gas limit increase is recommended so as to preserve the de-facto transactions-per-second processing capability of the system for average contracts.
+
+## References
+
+1. EIP-90, https://github.com/ethereum/EIPs/issues/90
+2. EIP-114, https://github.com/ethereum/EIPs/issues/114