Try parsing a message in main(), both in the main thread and in a QtConcurrent thread.

(cherry picked from commit 4446b277814ae4afe7d4aba85eb4fd5475843880)

Fixes issue 3265

src/main.cpp

@@ -50,6 +50,8 @@
 #include "version.h"
 #include "widgets/osd.h"
 
+#include "tagreadermessages.pb.h"
+
 #include "qtsingleapplication.h"
 #include "qtsinglecoreapplication.h"
 
@@ -61,6 +63,7 @@
 #include <QSqlQuery>
 #include <QTextCodec>
 #include <QTranslator>
+#include <QtConcurrentRun>
 #include <QtDebug>
 
 #include <glib-object.h>
@@ -225,6 +228,17 @@ void ScanGIOModulePath() {
 }
 #endif
 
+void ParseAProto() {
+  const QByteArray data = QByteArray::fromHex(
+        "08001a8b010a8801b2014566696c653a2f2f2f453a2f4d7573696b2f28414c42554d2"
+        "9253230476f74616e25323050726f6a6563742532302d253230416d6269656e742532"
+        "304c6f756e67652e6d786dba012a28414c42554d2920476f74616e2050726f6a65637"
+        "4202d20416d6269656e74204c6f756e67652e6d786dc001c7a7efd104c801bad685e4"
+        "04d001eeca32");
+  pb::tagreader::Message message;
+  message.ParseFromArray(data.constData(), data.size());
+}
+
 int main(int argc, char *argv[]) {
   if (CrashReporting::SendCrashReport(argc, argv)) {
     return 0;
@@ -391,6 +405,12 @@ int main(int argc, char *argv[]) {
   // Icons
   IconLoader::Init();
 
+  // This is a nasty hack to ensure that everything in libprotobuf is
+  // initialised in the main thread.  It fixes issue 3265 but nobody knows why.
+  // Don't remove this unless you can reproduce the error that it fixes.
+  ParseAProto();
+  QtConcurrent::run(&ParseAProto);
+
   Application app;
 
   Echonest::Config::instance()->setAPIKey("DFLFLJBUF4EGTXHIG");