From 1aa1ea7bea5f0921fd925fba042dc1cf0d1e119f Mon Sep 17 00:00:00 2001
From: Hannah von Reth <hannah.vonreth@owncloud.com>
Date: Fri, 14 Aug 2020 16:15:30 +0200
Subject: [PATCH] Return empty string instead of 1 as adler32 checksum for
 empty files

---
 src/common/checksums.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/common/checksums.cpp b/src/common/checksums.cpp
index 60c8c9b77..f75e84f28 100644
--- a/src/common/checksums.cpp
+++ b/src/common/checksums.cpp
@@ -114,6 +114,10 @@ QByteArray calcSha1(QIODevice *device)
 #ifdef ZLIB_FOUND
 QByteArray calcAdler32(QIODevice *device)
 {
+    if (device->size() == 0)
+    {
+        return QByteArray();
+    }
     QByteArray buf(BUFSIZE, Qt::Uninitialized);
 
     unsigned int adler = adler32(0L, Z_NULL, 0);