Render incremental rendering image at proper location

The old behavior was to render it at the currently visibleExtent based on the
map canvas. The job may however have been scheduled for a different extent and
therefore rendered at an improper location.

python/core/qgsmaprendererjob.sip

@@ -89,6 +89,13 @@ class QgsMapRendererJob : QObject
     //! Find out how log it took to finish the job (in miliseconds)
     int renderingTime() const;
 
+    /**
+     * Return map settings with which this job was started.
+     * @return A QgsMapSettings instance with render settings
+     * @note added in 2.8
+     */
+    const QgsMapSettings& mapSettings() const;
+
   signals:
 
     //! emitted when asynchronous rendering is finished (or canceled).

src/core/qgsmaprendererjob.cpp

@@ -56,6 +56,11 @@ void QgsMapRendererJob::setCache( QgsMapRendererCache* cache )
   mCache = cache;
 }
 
+const QgsMapSettings& QgsMapRendererJob::mapSettings() const
+{
+  return mSettings;
+}
+
 
 bool QgsMapRendererJob::reprojectToLayerExtent( const QgsCoordinateTransform* ct, bool layerCrsGeographic, QgsRectangle& extent, QgsRectangle& r2 )
 {

src/core/qgsmaprendererjob.h

@@ -126,6 +126,13 @@ class CORE_EXPORT QgsMapRendererJob : public QObject
     //! Find out how log it took to finish the job (in miliseconds)
     int renderingTime() const { return mRenderingTime; }
 
+    /**
+     * Return map settings with which this job was started.
+     * @return A QgsMapSettings instance with render settings
+     * @note added in 2.8
+     */
+    const QgsMapSettings& mapSettings() const;
+
   signals:
 
     //! emitted when asynchronous rendering is finished (or canceled).

src/gui/qgsmapcanvas.cpp

@@ -737,10 +737,9 @@ void QgsMapCanvas::rendererJobFinished()
 
 void QgsMapCanvas::mapUpdateTimeout()
 {
-  mMap->setContent( mJob->renderedImage(), mSettings.visibleExtent() );
+  mMap->setContent( mJob->renderedImage(), mJob->mapSettings().visibleExtent() );
 }
 
-
 void QgsMapCanvas::stopRendering()
 {
   if ( mJob )