From 9a0e811b8b3b0fda7608b0920e81cb17aad68bd2 Mon Sep 17 00:00:00 2001
From: E Spelt <espelt@activetickets.com>
Date: Fri, 18 Nov 2022 23:55:54 +0100
Subject: [PATCH] fix: Overflow on Android when overflow check is off. Related
 to:  https://github.com/Spelt/ZXing.Delphi/issues/123

---
 Lib/Classes/Common/ZXing.Common.BitArrayImplementation.pas | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Lib/Classes/Common/ZXing.Common.BitArrayImplementation.pas b/Lib/Classes/Common/ZXing.Common.BitArrayImplementation.pas
index 9413c9d..733abb9 100644
--- a/Lib/Classes/Common/ZXing.Common.BitArrayImplementation.pas
+++ b/Lib/Classes/Common/ZXing.Common.BitArrayImplementation.pas
@@ -158,7 +158,10 @@ function TBitArrayImplementation.getNextUnset(from: Integer): Integer;
   currentBits := not Fbits[bitsOffset];
 
   // mask off lesser bits first
-  currentBits := currentBits and (not( (1 shl (from and $1F)) - 1));
+  {$OVERFLOWCHECKS OFF}
+  currentBits := currentBits and -(1 shl (from and $1F));
+  {$OVERFLOWCHECKS ON}
+
   while (currentBits = 0) do
   begin
     Inc(bitsOffset);