qmlpreview: Don't try to compile .(m)js files as QML

We need to evict them from the cache on reload, but we shouldn't
re-compile them right away. That can be done on-demand the next time
they're requested.

Pick-to: 6.12
Fixes: QTBUG-150558
Change-Id: Ia339ee0f9ab110c3517a4c06cf150cfa99110246
Reviewed-by: Olivier De Cannière <olivier.decanniere@qt.io>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/plugins/qmltooling/qmldbg_preview/qqmlinplacepreviewhandler.cpp b/src/plugins/qmltooling/qmldbg_preview/qqmlinplacepreviewhandler.cpp
index 21853852fd..90e3b6338b 100644
--- a/src/plugins/qmltooling/qmldbg_preview/qqmlinplacepreviewhandler.cpp
+++ b/src/plugins/qmltooling/qmldbg_preview/qqmlinplacepreviewhandler.cpp
@@ -200,10 +200,16 @@ void updateEngine(std::shared_ptr<InplaceUpdate> inplaceUpdate, const QList<QUrl
 {
     QV4::ExecutionEngine *v4 = inplaceUpdate->engine->handle();
     std::vector<QQmlComponent *> components;
+    QQmlTypeLoader *typeLoader = v4->typeLoader();
     for (const QUrl &url : urls) {
+        // Any file the application requests from the preview client is reported as dropped.
+        // Only QML documents can be recompiled as components. Scripts and qmldir files are merely
+        // evicted from the cache.
+        const bool isQmlDocument = typeLoader->isTypeLoaded(QQmlMetaType::normalizedUrl(url));
+
         // First remove any cached instance of the CU
         // NB: Don't remove from the ExecutionEngine's list of CUs. We need those for the GC.
-        if (!v4->typeLoader()->removeFromCache(url))
+        if (!typeLoader->removeFromCache(url) || !isQmlDocument)
             continue;
 
         // Hold on to the old unit.