From 0b45bc5fc6b42b3f29f8e811e216d7cf768cb398 Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Tue, 8 Jan 2019 22:06:31 +0100
Subject: [PATCH] BMP: support bitmask of more than 8 bits

---
 src/fileformats.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/fileformats.c b/src/fileformats.c
index 50cd8821..91b34680 100644
--- a/src/fileformats.c
+++ b/src/fileformats.c
@@ -3120,8 +3120,10 @@ void Test_BMP(T_IO_Context * context, FILE * file)
 static byte Bitmap_mask(dword pixel, dword mask, int bits, int shift)
 {
   dword value = (pixel & mask) >> shift;
-  if (bits != 8)
+  if (bits < 8)
     value = (value << (8 - bits)) | (value >> (2 * bits - 8));
+  else if (bits > 8)
+    value >>= (bits - 8);
   return (byte)value;
 }