From 10b6121cb8bcfd7f147c1e502d9c9846b3a7a54a Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Mon, 9 Mar 2020 17:20:15 +0100
Subject: [PATCH] Fix deserialization format of events

Apparently it uses VLAs, but in a very sneaky way.
---
 src/common/serialization.cpp | 12 +++++++-----
 src/common/serialization.h   | 13 +++++++++++--
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/common/serialization.cpp b/src/common/serialization.cpp
index ac9baddb..ea102895 100644
--- a/src/common/serialization.cpp
+++ b/src/common/serialization.cpp
@@ -16,20 +16,22 @@
 
 #include "serialization.h"
 
-#include <iostream>
-
 DynamicVstEvents::DynamicVstEvents(const VstEvents& c_events)
     : events(c_events.numEvents) {
     // Copy from the C-style array into a vector for serialization
     for (int i = 0; i < c_events.numEvents; i++) {
-        events[i] = c_events.events[0][i];
+        events[i] = *c_events.events[i];
     }
 }
 
 VstEvents& DynamicVstEvents::as_c_events() {
-    // Populate the vst_events struct with data from the vector
     vst_events.numEvents = events.size();
-    vst_events.events[0] = events.data();
+
+    // Populate the vst_events struct with data from the vector. This will
+    // overflow past the defined length of `vst_events.events` because it's
+    // actually a VLA. This is why I put some padding at the end of this struct.
+    std::transform(events.begin(), events.end(), &vst_events.events[0],
+                   [](VstEvent& event) -> VstEvent* { return &event; });
 
     return vst_events;
 }
diff --git a/src/common/serialization.h b/src/common/serialization.h
index da3e685f..20d889e2 100644
--- a/src/common/serialization.h
+++ b/src/common/serialization.h
@@ -80,9 +80,9 @@ overload(Ts...)->overload<Ts...>;
  *
  * Before serialization the events are read from a C-style array into a vector
  * using this class's constructor, and after deserializing the original struct
- * can be obtained again usign the `as_c_events()` method.
+ * can be reconstructed usign the `as_c_events()` method.
  */
-class DynamicVstEvents {
+class alignas(16) DynamicVstEvents {
    public:
     DynamicVstEvents(){};
 
@@ -107,6 +107,15 @@ class DynamicVstEvents {
      * vector has been filled.
      */
     VstEvents vst_events;
+    /**
+     * The `VstEvents` struct is defined to look like it contains a one or two
+     * element array of `VstEvent` pointers. The actual truth is that the
+     * `VstEvents::event` array is actually a variable length array with length
+     * `VstEvents::numEvents`. This is probably not part of any header files
+     * because VLAs are not part of any C++ standard. This struct is here to
+     * make sure there is enough room to copy the elements into.
+     */
+    size_t dummy[max_midi_events];
 };
 
 /**