From e511d33a7c281548c550388d7216a90c15f68636 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Wed, 14 Oct 2020 21:42:41 -0400
Subject: [PATCH] Adds test for [d], y; fixes implementation.

---
 .../65816AddressingTests.swift                | 26 ++++++++++++++++---
 .../Implementation/65816Implementation.hpp    |  3 ++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/OSBindings/Mac/Clock SignalTests/65816AddressingTests.swift b/OSBindings/Mac/Clock SignalTests/65816AddressingTests.swift
index bbb66db99..caea8529b 100644
--- a/OSBindings/Mac/Clock SignalTests/65816AddressingTests.swift	
+++ b/OSBindings/Mac/Clock SignalTests/65816AddressingTests.swift	
@@ -428,9 +428,7 @@ class WDC65816AddressingTests: XCTestCase {
 		XCTAssertEqual(machine.value(for: .A), 0xcdab)
 	}
 
-	// TODO: all tests from this point downward.
-
-	func testIndirectDirectYLong() {
+	func testIndirectYLong() {
 		// "If the D register is $FF00 and the m flag is 0, then for LDA [$FE],Y, the address
 		// of the low byte of the pointer is $00FFFE, the address of the middle byte is $00FFFF,
 		// and the address of the high byte is $000000. Furthermore, if the Y register is $000A, and
@@ -439,8 +437,30 @@ class WDC65816AddressingTests: XCTestCase {
 		//	* $00FFFF contains $FF
 		// then LDA [$FE],Y loads the low byte of the data from address $130006, and the high byte
 		// from $130007."
+		let machine = machine16()
+
+		machine.setValue(0xff00, for: .direct)
+		machine.setValue(0x000a, for: .Y)
+		machine.setValue(0x12, for: .dataBank)
+
+		machine.setValue(0x12, forAddress: 0x0000)
+		machine.setValue(0xfc, forAddress: 0xfffe)
+		machine.setValue(0xff, forAddress: 0xffff)
+
+		machine.setValue(0xab, forAddress: 0x130006)
+		machine.setValue(0xcd, forAddress: 0x130007)
+
+		// LDA [$fe], y; NOP
+		machine.setData(Data([0xb7, 0xfe, 0xea]), atAddress: 0x0200)
+
+		machine.setValue(0x200, for: .programCounter)
+		machine.runForNumber(ofCycles: 8)
+
+		XCTAssertEqual(machine.value(for: .A), 0xcdab)
 	}
 
+	// TODO: all tests from this point downward.
+
 	func testLong() {
 		// "If the m flag is 0, then LDA $12FFFF loads the low byte of the data from address $12FFFF,
 		// and the high byte from address $130000."
diff --git a/Processors/65816/Implementation/65816Implementation.hpp b/Processors/65816/Implementation/65816Implementation.hpp
index 9366747c7..2cbb792bb 100644
--- a/Processors/65816/Implementation/65816Implementation.hpp
+++ b/Processors/65816/Implementation/65816Implementation.hpp
@@ -315,8 +315,9 @@ template <typename BusHandler> void Processor<BusHandler>::run_for(const Cycles
 			continue;
 
 			case OperationConstructDirectIndirectIndexedLong:
-				data_address_ = y() + instruction_buffer_.value;
+				data_address_ = y() + data_buffer_.value;
 				data_address_increment_mask_ = 0xff'ff'ff;
+				data_buffer_.clear();
 			continue;
 
 			case OperationConstructDirectIndirectLong: