From 950d0ad1d37a8b68b13fef9dbab47bf5a76b552a Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Tue, 12 Apr 2022 23:12:45 +1000
Subject: [PATCH] Fixed behaviour change from #5901 endian fix

---
 Tests/images/issue_6194.j2k   | Bin 0 -> 318 bytes
 Tests/test_file_jpeg2k.py     |   5 +++++
 src/libImaging/Jpeg2KDecode.c |   6 ++++--
 3 files changed, 9 insertions(+), 2 deletions(-)
 create mode 100644 Tests/images/issue_6194.j2k

diff --git a/Tests/images/issue_6194.j2k b/Tests/images/issue_6194.j2k
new file mode 100644
index 0000000000000000000000000000000000000000..b1b8851670bb5764c080a41d3e9ea0285ba22ba6
GIT binary patch
literal 318
zcmezG|38pHlK})cpcu>n5-d;*;WP3xGX4)@-~sX&8JJjD7#RP@FmO3EbaYGrqW>uj
zstk<IMX8A;sVNFcl?wg^sd-)juI>tDsYS(^`FRRPdM0`X|0ghTfsHc&YM*@mj{y%C
z&*TFPKN$`%2pnLLWnpJ#2J#pWFjxuje6;1!2CHWT>M%yAuLr4Lz#z||z{q}pp+?Dp
z!AgXIp@Yf&e?50US3Ot@6HtpOiWZ>pKx8N2z|717u|m*+fun)v&wOrsUWg`Upe8ef
jCVQaa3P6|eFfc!4VPpo{^^*x=R||JSd_8wE<NuogE%Q(S

literal 0
HcmV?d00001

diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index 677a149810f..7942d6b9afd 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -298,6 +298,11 @@ def test_16bit_jp2_roundtrips():
         assert_image_equal(im, jp2)
 
 
+def test_issue_6194():
+    with Image.open("Tests/images/issue_6194.j2k") as im:
+        assert im.getpixel((5, 5)) == 31
+
+
 def test_unbound_local():
     # prepatch, a malformed jp2 file could cause an UnboundLocalError exception.
     with pytest.raises(OSError):
diff --git a/src/libImaging/Jpeg2KDecode.c b/src/libImaging/Jpeg2KDecode.c
index 8f27d87d88c..cff30e2d0bf 100644
--- a/src/libImaging/Jpeg2KDecode.c
+++ b/src/libImaging/Jpeg2KDecode.c
@@ -180,11 +180,13 @@ j2ku_gray_i(
         case 2:
             for (y = 0; y < h; ++y) {
                 const UINT16 *data = (const UINT16 *)&tiledata[2 * y * w];
-                UINT8 *row = (UINT8 *)im->image[y0 + y] + x0;
+                UINT16 *row = (UINT16 *)im->image[y0 + y] + x0;
                 for (x = 0; x < w; ++x) {
                     UINT16 pixel = j2ku_shift(offset + *data++, shift);
+                    #ifdef WORDS_BIGENDIAN
+                        pixel = (pixel >> 8) | (pixel << 8);
+                    #endif
                     *row++ = pixel;
-                    *row++ = pixel >> 8;
                 }
             }
             break;