QQuickPixmapReader: Trigger typeloader creation before thread start

The type loader can be requested from different threads but should be
created on the engine thread.

Amends commit d2bc4a4330254c0c68a0ade51b59a71c4b67b470

Fixes: QTBUG-137848
Change-Id: I30d93e6351bd67ded94956f9832cb87157823373
Reviewed-by: Olivier De Cannière <[email protected]>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/quick/util/qquickpixmapcache.cpp b/src/quick/util/qquickpixmapcache.cpp
index 3f412bf84a..2b629739d8 100644
--- a/src/quick/util/qquickpixmapcache.cpp
+++ b/src/quick/util/qquickpixmapcache.cpp
@@ -597,6 +597,11 @@ QQuickPixmapReader::QQuickPixmapReader(QQmlEngine *eng)
 , accessManager(nullptr)
 #endif
 {
+    // Make sure the type loader exists before we start the thread.
+    // We might need it to create a network access manager and we must
+    // construct it from the engine thread.
+    engine->handle()->typeLoader();
+
     Q_DETACH_THREAD_AFFINITY_MARKER(m_readerThreadAffinityMarker);
 #if QT_CONFIG(quick_pixmap_cache_threaded_download)
     eventLoopQuitHack = new QObject;