From 1e11a893b48165e050f33e7816e4d13f232c8244 Mon Sep 17 00:00:00 2001
From: Agustin Aguilar <Agustin@bitpagos.com>
Date: Wed, 22 May 2019 03:31:19 +0200
Subject: [PATCH] Fix Wrong Input Length - ERC165 Example (#1640)

* Wrong input size - noThrowCall ERC165

Input should be 36 bytes (4 signature bytes + 32 bytes parameter)

Solidity 5 validates the length of msg.data, reverting on the 32 bytes input, all contracts using the broken 'doesContractImplementInterface' will not be able to read an ERC165 implementation targetting Solidity 5.

A legacy-compatible strategy should be defined to make all the "ERC165 readers" sending a 32 bytes sized data compatible with ERC165 contracts compiled targeting this new version of the compiler.

A possible solution could be to add a keyword on Solidity to disable the validation of the calldata length.

* Add version history section to EIP165

* EIP 1640 -> PR 1640
---
 EIPS/eip-165.md | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/EIPS/eip-165.md b/EIPS/eip-165.md
index e71e96e02a462..b930acbcc045d 100644
--- a/EIPS/eip-165.md
+++ b/EIPS/eip-165.md
@@ -151,7 +151,7 @@ contract ERC165Query {
                                     30000,         // 30k gas
                                     _contract,     // To addr
                                     x,             // Inputs are stored at location x
-                                    0x20,          // Inputs are 32 bytes long
+                                    0x24,          // Inputs are 36 bytes long
                                     x,             // Store output over input (saves space)
                                     0x20)          // Outputs are 32 bytes long
 
@@ -225,6 +225,11 @@ contract Homer is ERC165, Simpson {
 
 With three or more supported interfaces (including ERC165 itself as a required supported interface), the mapping approach (in every case) costs less gas than the pure approach (at worst case).
 
+## Version history
+* PR 1640, finalized 2019-01-23 -- This corrects the noThrowCall test case to use 36 bytes rather than the previous 32 bytes. The previous code was an error that still silently worked in Solidity 0.4.x but which was broken by new behavior introduced in Solidity 0.5.0. This change was discussed at [#1640](https://github.com/ethereum/EIPs/pull/1640).
+
+* EIP 165, finalized 2018-04-20 -- Original published version.
+
 ## Copyright
 
 Copyright and related rights waived via [CC0](https://creativecommons.org/publicdomain/zero/1.0/).