From 05873f3d82f4f68c5d2ffe1ea3c63bfc320bea7d Mon Sep 17 00:00:00 2001
From: Wohlstand <admin@wohlnet.ru>
Date: Fri, 16 Oct 2020 11:44:03 +0300
Subject: [PATCH] libADLMIDI and libOPNMIDI: Fixed an infinite loop caused the
 stuck

Recently I've got the report from @drfrag666 that at LZDoom some banks
do cause the dead freeze and that is probably because of the merge
problems. However, after my research, I found the bug at me: in a very
special case, a zero delay value may appear that will cause the stuck.
---
 thirdparty/adlmidi/adlmidi.cpp | 4 ++++
 thirdparty/opnmidi/opnmidi.cpp | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/thirdparty/adlmidi/adlmidi.cpp b/thirdparty/adlmidi/adlmidi.cpp
index 6b28e06..469ff09 100644
--- a/thirdparty/adlmidi/adlmidi.cpp
+++ b/thirdparty/adlmidi/adlmidi.cpp
@@ -1311,6 +1311,8 @@ ADLMIDI_EXPORT int adl_playFormat(ADL_MIDIPlayer *device, int sampleCount,
     while(left > 0)
     {
         {//...
+            if(setup.delay <= 0.0)
+                setup.delay = double(left / 2) / double(setup.PCM_RATE);
             const double eat_delay = setup.delay < setup.maxdelay ? setup.delay : setup.maxdelay;
             if(hasSkipped)
             {
@@ -1419,6 +1421,8 @@ ADLMIDI_EXPORT int adl_generateFormat(struct ADL_MIDIPlayer *device, int sampleC
     while(left > 0)
     {
         {//...
+            if(delay <= 0.0)
+                delay = double(left / 2) / double(setup.PCM_RATE);
             const double eat_delay = delay < setup.maxdelay ? delay : setup.maxdelay;
             delay -= eat_delay;
             setup.carry += double(setup.PCM_RATE) * eat_delay;
diff --git a/thirdparty/opnmidi/opnmidi.cpp b/thirdparty/opnmidi/opnmidi.cpp
index 49c71e0..1770352 100644
--- a/thirdparty/opnmidi/opnmidi.cpp
+++ b/thirdparty/opnmidi/opnmidi.cpp
@@ -1044,6 +1044,8 @@ OPNMIDI_EXPORT int opn2_playFormat(OPN2_MIDIPlayer *device, int sampleCount,
     while(left > 0)
     {
         {//
+            if(setup.delay <= 0.0)
+                setup.delay = double(left / 2) / double(setup.PCM_RATE);
             const double eat_delay = setup.delay < setup.maxdelay ? setup.delay : setup.maxdelay;
             if(hasSkipped)
             {
@@ -1139,6 +1141,8 @@ OPNMIDI_EXPORT int opn2_generateFormat(struct OPN2_MIDIPlayer *device, int sampl
     while(left > 0)
     {
         {//
+            if(delay <= 0.0)
+                delay = double(left / 2) / double(setup.PCM_RATE);
             const double eat_delay = delay < setup.maxdelay ? delay : setup.maxdelay;
             delay -= eat_delay;
             setup.carry += double(setup.PCM_RATE) * eat_delay;