From 12dcd352dba3ce163f4c542cf390da59dcf12fd2 Mon Sep 17 00:00:00 2001
From: Nathan Hourt <nat.hourt@gmail.com>
Date: Wed, 2 Aug 2017 15:49:35 -0500
Subject: [PATCH] Ref #123: Define/Implement unlinkauth

Add an unlinkauth message type which removes a link from a message type
to a required authority
---
 libraries/native_contract/eos_contract.cpp            | 11 ++++++++++-
 .../include/eos/native_contract/eos_contract.hpp      |  1 +
 .../native_contract_chain_initializer.cpp             |  1 +
 libraries/types/types.eos                             |  5 +++++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/libraries/native_contract/eos_contract.cpp b/libraries/native_contract/eos_contract.cpp
index 13117b56818..d617174980e 100644
--- a/libraries/native_contract/eos_contract.cpp
+++ b/libraries/native_contract/eos_contract.cpp
@@ -378,7 +378,7 @@ void apply_eos_linkauth(apply_context& context) {
    
    if (link) {
       EOS_ASSERT(link->required_permission != requirement.requirement, message_precondition_exception,
-                 "Attempting to update required authority, but new requirement is same as old.");
+                 "Attempting to update required authority, but new requirement is same as old");
       db.modify(*link, [requirement = requirement.requirement](permission_link_object& link) {
          link.required_permission = requirement;
       });
@@ -392,5 +392,14 @@ void apply_eos_linkauth(apply_context& context) {
    }
 }
 
+void apply_eos_unlinkauth(apply_context& context) {
+   auto& db = context.mutable_db;
+   auto unlink = context.msg.as<types::unlinkauth>();
+   auto linkKey = boost::make_tuple(unlink.account, unlink.code, unlink.type);
+   auto link = db.find<permission_link_object, by_message_type>(linkKey);
+   EOS_ASSERT(link != nullptr, message_precondition_exception, "Attempting to unlink authority, but no link found");
+   db.remove(*link);
+}
+
 } // namespace eos
 } // namespace native
diff --git a/libraries/native_contract/include/eos/native_contract/eos_contract.hpp b/libraries/native_contract/include/eos/native_contract/eos_contract.hpp
index 9866dbd6f4c..e820a6dc9b1 100644
--- a/libraries/native_contract/include/eos/native_contract/eos_contract.hpp
+++ b/libraries/native_contract/include/eos/native_contract/eos_contract.hpp
@@ -19,6 +19,7 @@ void apply_eos_setproducer(chain::apply_context&);
 void apply_eos_setproxy(chain::apply_context&);
 void apply_eos_setcode(chain::apply_context&);
 void apply_eos_linkauth(chain::apply_context&);
+void apply_eos_unlinkauth(chain::apply_context&);
 
 } // namespace eos
 } // namespace native
diff --git a/libraries/native_contract/native_contract_chain_initializer.cpp b/libraries/native_contract/native_contract_chain_initializer.cpp
index bbf0519ff76..ba5c0bb2e09 100644
--- a/libraries/native_contract/native_contract_chain_initializer.cpp
+++ b/libraries/native_contract/native_contract_chain_initializer.cpp
@@ -49,6 +49,7 @@ void native_contract_chain_initializer::register_types(chain_controller& chain,
    SET_APP_HANDLER( eos, eos, setproxy );
    SET_APP_HANDLER( eos, eos, setcode );
    SET_APP_HANDLER( eos, eos, linkauth );
+   SET_APP_HANDLER( eos, eos, unlinkauth );
 }
 
 std::vector<chain::Message> native_contract_chain_initializer::prepare_database(chain_controller& chain,
diff --git a/libraries/types/types.eos b/libraries/types/types.eos
index 5aaea9332b6..f2f684ee8d6 100644
--- a/libraries/types/types.eos
+++ b/libraries/types/types.eos
@@ -131,3 +131,8 @@ struct linkauth
    code        AccountName # The contract to require permissions to invoke
    type        FuncName
    requirement PermissionName # The permission name to require
+
+struct unlinkauth
+   account     AccountName # The account to require permissions for
+   code        AccountName # The contract to require permissions to invoke
+   type        FuncName