From 1e84682b5c437857e0a1483d007f1c0d0651c987 Mon Sep 17 00:00:00 2001
From: itsmattkc <itsmattkc@gmail.com>
Date: Fri, 15 Feb 2019 23:24:03 -0800
Subject: [PATCH] better thread syncing in loading

---
 io/loadthread.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/io/loadthread.cpp b/io/loadthread.cpp
index fb663212f..1c50389fa 100644
--- a/io/loadthread.cpp
+++ b/io/loadthread.cpp
@@ -716,11 +716,13 @@ void LoadThread::cancel() {
 }
 
 void LoadThread::question_func(const QString &title, const QString &text, int buttons) {
+    mutex.lock();
 	question_btn = QMessageBox::warning(
                     Olive::MainWindow,
 					title,
 					text,
 					static_cast<enum QMessageBox::StandardButton>(buttons));
+    mutex.unlock();
 	waitCond.wakeAll();
 }
 
@@ -795,6 +797,9 @@ void LoadThread::create_effect_ui(
 	 * Sorry. I'll fix it one day.
 	 */
 
+    // lock mutex - ensures the load thread is suspended while this happens
+    mutex.lock();
+
 	if (cancelled) return;
 	if (type == TA_NO_TRANSITION) {
 		if (meta == nullptr) {
@@ -824,13 +829,22 @@ void LoadThread::create_effect_ui(
 		}
 	}
 
+    mutex.unlock();
+
 	waitCond.wakeAll();
 }
 
 void LoadThread::create_dual_transition(const TransitionData* td, Clip* primary, Clip* secondary, const EffectMeta* meta) {
+    // lock mutex - ensures the load thread is suspended while this happens
+    mutex.lock();
+
 	int transition_index = create_transition(primary, secondary, meta);
 	primary->sequence->transitions.at(transition_index)->set_length(td->length);
 	if (td->otc != nullptr) td->otc->opening_transition = transition_index;
 	if (td->ctc != nullptr) td->ctc->closing_transition = transition_index;
+
+    mutex.unlock();
+
+    // resume load thread
 	waitCond.wakeAll();
 }