From 1c932952242560fb356e0a875b0833738714c87f Mon Sep 17 00:00:00 2001
From: Carson Hicks <developer@carson.im>
Date: Fri, 23 Jan 2026 22:27:18 -0800
Subject: [PATCH] fix: Make document partial md5sum calculation for KOReader
 sync match KOReader behavior

---
 lib/KOReaderSync/KOReaderDocumentId.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/KOReaderSync/KOReaderDocumentId.cpp b/lib/KOReaderSync/KOReaderDocumentId.cpp
index 2c52464c..b33beb75 100644
--- a/lib/KOReaderSync/KOReaderDocumentId.cpp
+++ b/lib/KOReaderSync/KOReaderDocumentId.cpp
@@ -33,10 +33,10 @@ std::string KOReaderDocumentId::calculateFromFilename(const std::string& filePat
 
 size_t KOReaderDocumentId::getOffset(int i) {
   // Offset = 1024 << (2*i)
-  // For i = -1: 1024 >> 2 = 256
+  // For i = -1: KOReader uses a value of 0
   // For i >= 0: 1024 << (2*i)
   if (i < 0) {
-    return CHUNK_SIZE >> (-2 * i);
+    return 0;
   }
   return CHUNK_SIZE << (2 * i);
 }