From b3af769c1a85e62600d6bbf38a9e66639a60d43c Mon Sep 17 00:00:00 2001
From: Andrew Murray <radarhere@users.noreply.github.com>
Date: Thu, 2 Feb 2023 20:52:50 +1100
Subject: [PATCH] Set alpha channel for OpenJPEG

---
 src/libImaging/Jpeg2KEncode.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/libImaging/Jpeg2KEncode.c b/src/libImaging/Jpeg2KEncode.c
index db1c5c0c9..62d22bcc6 100644
--- a/src/libImaging/Jpeg2KEncode.c
+++ b/src/libImaging/Jpeg2KEncode.c
@@ -487,6 +487,10 @@ j2k_encode_entry(Imaging im, ImagingCodecState state) {
         goto quick_exit;
     }
 
+    if (strcmp(im->mode, "RGBA") == 0) {
+        image->comps[3].alpha = 1;
+    }
+
     opj_set_error_handler(codec, j2k_error, context);
     opj_set_info_handler(codec, j2k_warn, context);
     opj_set_warning_handler(codec, j2k_warn, context);