From 8dd7527dc8b16e3da2c21a5541aee2f82bd532dc Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Thu, 26 May 2016 00:07:07 -0700
Subject: [PATCH] Clamp reads at the beginning too.

Safer, avoids an index overrun in disk cache.
---
 Core/FileLoaders/CachingFileLoader.cpp     | 6 ++++++
 Core/FileLoaders/DiskCachingFileLoader.cpp | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/Core/FileLoaders/CachingFileLoader.cpp b/Core/FileLoaders/CachingFileLoader.cpp
index dc4518a68d..0b34e2c7bb 100644
--- a/Core/FileLoaders/CachingFileLoader.cpp
+++ b/Core/FileLoaders/CachingFileLoader.cpp
@@ -68,6 +68,12 @@ void CachingFileLoader::Seek(s64 absolutePos) {
 }
 
 size_t CachingFileLoader::ReadAt(s64 absolutePos, size_t bytes, void *data) {
+	if (absolutePos >= filesize_) {
+		bytes = 0;
+	} else if (absolutePos + (s64)bytes >= filesize_) {
+		bytes = filesize_ - absolutePos;
+	}
+
 	size_t readSize = ReadFromCache(absolutePos, bytes, data);
 	// While in case the cache size is too small for the entire read.
 	while (readSize < bytes) {
diff --git a/Core/FileLoaders/DiskCachingFileLoader.cpp b/Core/FileLoaders/DiskCachingFileLoader.cpp
index 5bb49a82cd..27379a9bc9 100644
--- a/Core/FileLoaders/DiskCachingFileLoader.cpp
+++ b/Core/FileLoaders/DiskCachingFileLoader.cpp
@@ -76,6 +76,12 @@ void DiskCachingFileLoader::Seek(s64 absolutePos) {
 size_t DiskCachingFileLoader::ReadAt(s64 absolutePos, size_t bytes, void *data) {
 	size_t readSize;
 
+	if (absolutePos >= filesize_) {
+		bytes = 0;
+	} else if (absolutePos + (s64)bytes >= filesize_) {
+		bytes = filesize_ - absolutePos;
+	}
+
 	if (cache_ && cache_->IsValid()) {
 		readSize = cache_->ReadFromCache(absolutePos, bytes, data);
 		// While in case the cache size is too small for the entire read.