From 78b0e06dbbe8f7cdeee1fd9234c13b6d4d997876 Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 14 Oct 2025 23:41:50 +1100
Subject: [PATCH] Shift bits before making value negative

---
 src/libImaging/BcnDecode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libImaging/BcnDecode.c b/src/libImaging/BcnDecode.c
index 7b3d8f908..ac81ed6df 100644
--- a/src/libImaging/BcnDecode.c
+++ b/src/libImaging/BcnDecode.c
@@ -603,7 +603,7 @@ static void
 bc6_sign_extend(UINT16 *v, int prec) {
     int x = *v;
     if (x & (1 << (prec - 1))) {
-        x |= -1 << prec;
+        x |= -(1 << prec);
     }
     *v = (UINT16)x;
 }