From 240e5eb9e5dca81b5d3961c9088ede80dbfc8d99 Mon Sep 17 00:00:00 2001
From: negativeExponent <54053706+negativeExponent@users.noreply.github.com>
Date: Tue, 23 Jul 2024 10:08:29 +0800
Subject: [PATCH] winmm_midi: Fix midi_write_long_event unable to send sysex
 correctly (#16804)

data size has to be DWORD aligned.

Fix https://github.com/libretro/RetroArch/issues/16790

review before merge for confirmation/corrections:
@LibretroAdmin @zoltanvb and others
---
 midi/drivers/winmm_midi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/midi/drivers/winmm_midi.c b/midi/drivers/winmm_midi.c
index 0643626dfc..0d4dbba6a0 100644
--- a/midi/drivers/winmm_midi.c
+++ b/midi/drivers/winmm_midi.c
@@ -343,6 +343,9 @@ static bool winmm_midi_write_long_event(winmm_midi_buffer_t *buf,
 {
    DWORD i = buf->header.dwBytesRecorded / sizeof(DWORD);
 
+   /* data size has to be DWORD aligned */
+   data_size = (data_size + (sizeof(DWORD) - 1)) & ~(sizeof(DWORD) - 1);
+
    if (buf->header.dwBytesRecorded + sizeof(DWORD) * 3 + data_size >
          sizeof(DWORD) * WINMM_MIDI_BUF_LEN)
       return false;