compat/win32-com: default to right COM type without caller specifying it

The main window always needs the apartment threaded context for OLE used by
Qt. Default to apartment threaded before a QApplication is created, or if the
thread is the QApplication thread. Use multithreaded COM otherwise.

1 files changed, 14 insertions, 1 deletions

diff --git a/compat/win32-com.cpp b/compat/win32-com.cpp
index 689e1411..7bebc500 100644
--- a/compat/win32-com.cpp
+++ b/compat/win32-com.cpp
@@ -5,11 +5,24 @@
 #include "compat/util.hpp"
 
 #include <QString>
+#include <QCoreApplication>
+#include <QApplication>
 #include <QThread>
 #include <QDebug>
 
-bool OPENTRACK_COMPAT_EXPORT init_com_threading(com_type t)
+bool OPENTRACK_COMPAT_EXPORT init_com_threading(com_type t_)
 {
+    const com_type t = progn(
+                           if (t_ != com_invalid)
+                               return t_;
+                           if (QCoreApplication::instance() == nullptr)
+                               return com_apartment;
+                           if (qApp->thread() == QThread::currentThread())
+                               return com_apartment;
+                           else
+                               return com_multithreaded;
+                       );
+
     HRESULT ret = CoInitializeEx(0, t);
 
     if (ret != S_OK && ret != S_FALSE)