From e70052e963e174ded54b2453344924135e9ea25f Mon Sep 17 00:00:00 2001
From: marcrobledo <mark@tinet.org>
Date: Wed, 19 Sep 2018 09:44:18 +0200
Subject: [PATCH] fixed an important bug while creating IPS patches in some
 cases

---
 _cache_service_worker.js |  2 +-
 index.html               |  2 +-
 ips.js                   | 17 ++++++++++-------
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/_cache_service_worker.js b/_cache_service_worker.js
index efe9ed6..f46cbdf 100644
--- a/_cache_service_worker.js
+++ b/_cache_service_worker.js
@@ -12,7 +12,7 @@ limitations under the License.
 mod by marcrobledo, original from: https://github.com/GoogleChrome/samples/blob/gh-pages/service-worker/basic/service-worker.js
 */
 
-const PRECACHE_ID='v20180918';
+const PRECACHE_ID='v20180919';
 const PRECACHE_FILES=[
 'index.html','./',
 'RomPatcher.css',
diff --git a/index.html b/index.html
index 86dbd84..dfd4ae3 100644
--- a/index.html
+++ b/index.html
@@ -103,7 +103,7 @@
 
 <!-- FOOTER -->
 <footer>
-	Rom Patcher JS <small>rev20180918</small> by <a href="/">Marc Robledo</a>
+	Rom Patcher JS <small>rev20180919</small> by <a href="/">Marc Robledo</a>
 	<br />
 	<i class="icon github"></i> <a href="https://github.com/marcrobledo/RomPatcher.js/" target="_blank">See on GitHub</a>
 	<i class="icon heart"></i> <a href="https://www.paypal.me/marcrobledo/5" target="_blank" rel="nofollow">Donate</a>
diff --git a/ips.js b/ips.js
index 4340cfe..2c9d6d1 100644
--- a/ips.js
+++ b/ips.js
@@ -1,4 +1,4 @@
-/* IPS module for RomPatcher.js v20180428 - Marc Robledo 2016-2018 - http://www.marcrobledo.com/license */
+/* IPS module for RomPatcher.js v20180919 - Marc Robledo 2016-2018 - http://www.marcrobledo.com/license */
 /* File format specification: http://www.smwiki.net/wiki/IPS_file_format */
 
 var MAX_IPS_SIZE=16777216;
@@ -166,8 +166,9 @@ function createIPSFromFiles(original, modified){
 			var length=1;
 
 			/* find difference in next 6 bytes (in order to save space) */
+			/* force length to be 0xffff-6 bytes to keep IPS standard */
 			var nearbyDifference=true;
-			while(nearbyDifference){
+			while(nearbyDifference && length<(0xffff-6)){
 				if(seek+6>modified.fileSize){
 					var finalSeek=modified.fileSize-seek-1;
 					length+=finalSeek;
@@ -176,10 +177,7 @@ function createIPSFromFiles(original, modified){
 				}
 
 				for(var i=6;i>0 && nearbyDifference;i--){
-					var bc1=original.readByte(seek+i);
-					var bc2=modified.readByte(seek+i);
-
-					if(bc1!=bc2){
+					if(original.readByte(seek+i)!==modified.readByte(seek+i)){
 						length+=i;
 						seek+=i;
 						break;
@@ -197,7 +195,12 @@ function createIPSFromFiles(original, modified){
 			}
 
 			if(RLERecord){
-				tempFile.addRLERecord(originalSeek, length, data[0]);
+				if(length<3){
+					tempFile.addSimpleRecord(originalSeek, data);
+				}else{
+					tempFile.addRLERecord(originalSeek, length, data[0]);
+				}
+				//tempFile.addRLERecord(originalSeek, length, data[0]);
 			}else{
 				tempFile.addSimpleRecord(originalSeek, data);
 			}