From 91cd7e651b9de86efb8cc8c2859a947f73c2814a Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Mon, 9 Mar 2020 17:20:31 +1000
Subject: [PATCH] Disable canvas preview jobs when rotation is set on canvas

It's non-trivial to implement the preview jobs for rotated canvases,
and currently it just shows junk images

Fixes #34860

(cherry picked from commit 597aa5b61f08cf2790dc0acd32a8467173e21a79)
(cherry picked from commit 4916e393b16a62f917b8adf9cec3a3c01b1f8859)
---
 src/gui/qgsmapcanvas.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
index 54c3a21991af..b5b67baae9f5 100644
--- a/src/gui/qgsmapcanvas.cpp
+++ b/src/gui/qgsmapcanvas.cpp
@@ -2408,6 +2408,12 @@ const QgsLabelingEngineSettings &QgsMapCanvas::labelingEngineSettings() const
 void QgsMapCanvas::startPreviewJobs()
 {
   stopPreviewJobs(); //just in case still running
+
+  //canvas preview jobs aren't compatible with rotation
+  // TODO fix this
+  if ( !qgsDoubleNear( mSettings.rotation(), 0.0 ) )
+    return;
+
   schedulePreviewJob( 0 );
 }