[map themes] fix map renderer ignore theme blend and transparency lay…

…er settings

src/core/qgsmaprendererjob.cpp

@@ -285,12 +285,6 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter *painter, QgsLabelingEn
     LayerRenderJob &job = layerJobs.last();
     job.cached = false;
     job.img = nullptr;
-    job.blendMode = ml->blendMode();
-    job.opacity = 1.0;
-    if ( QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml ) )
-    {
-      job.opacity = vl->opacity();
-    }
     job.layer = ml;
     job.renderingTime = -1;
 
@@ -304,9 +298,23 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter *painter, QgsLabelingEn
     if ( mFeatureFilterProvider )
       job.context.setFeatureFilterProvider( mFeatureFilterProvider );
 
+    bool hasStyleOverride = mSettings.layerStyleOverrides().contains( ml->id() );
+    if ( hasStyleOverride )
+      ml->styleManager()->setOverrideStyle( mSettings.layerStyleOverrides().value( ml->id() ) );
+
+    job.blendMode = ml->blendMode();
+    job.opacity = 1.0;
+    if ( QgsVectorLayer *vl = qobject_cast<QgsVectorLayer *>( ml ) )
+    {
+      job.opacity = vl->opacity();
+    }
+
     // if we can use the cache, let's do it and avoid rendering!
     if ( mCache && mCache->hasCacheImage( ml->id() ) )
     {
+      if ( hasStyleOverride )
+        ml->styleManager()->restoreOverrideStyle();
+
       job.cached = true;
       job.imageInitialized = true;
       job.img = new QImage( mCache->cacheImage( ml->id() ) );
@@ -327,6 +335,9 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter *painter, QgsLabelingEn
                                       mSettings.outputImageFormat() );
       if ( mypFlattenedImage->isNull() )
       {
+        if ( hasStyleOverride )
+          ml->styleManager()->restoreOverrideStyle();
+
         mErrors.append( Error( ml->id(), tr( "Insufficient memory for image %1x%2" ).arg( mSettings.outputSize().width() ).arg( mSettings.outputSize().height() ) ) );
         delete mypFlattenedImage;
         layerJobs.removeLast();
@@ -339,18 +350,13 @@ LayerRenderJobs QgsMapRendererJob::prepareJobs( QPainter *painter, QgsLabelingEn
       job.context.setPainter( mypPainter );
     }
 
-    bool hasStyleOverride = mSettings.layerStyleOverrides().contains( ml->id() );
-    if ( hasStyleOverride )
-      ml->styleManager()->setOverrideStyle( mSettings.layerStyleOverrides().value( ml->id() ) );
-
     QTime layerTime;
     layerTime.start();
     job.renderer = ml->createMapRenderer( job.context );
     job.renderingTime = layerTime.elapsed(); // include job preparation time in layer rendering time
 
     if ( hasStyleOverride )
       ml->styleManager()->restoreOverrideStyle();
-
   } // while (li.hasPrevious())
 
   return layerJobs;