From d4c963e1c2fdc497dba038896caf2b3f975240ff Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Thu, 8 Oct 2020 16:14:29 +1000
Subject: [PATCH] [3d] Fix crash when line feature cannot be buffered

E.g. when it has only one vertex

(cherry picked from commit f6eed85729a8cbf913155ae16df7499f688ba0fa)
---
 src/3d/symbols/qgsline3dsymbol_p.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/3d/symbols/qgsline3dsymbol_p.cpp b/src/3d/symbols/qgsline3dsymbol_p.cpp
index 4f129e3fd423..34da5c5ea68d 100644
--- a/src/3d/symbols/qgsline3dsymbol_p.cpp
+++ b/src/3d/symbols/qgsline3dsymbol_p.cpp
@@ -115,6 +115,8 @@ void QgsBufferedLine3DSymbolHandler::processFeature( QgsFeature &f, const Qgs3DR
 
   QgsGeos engine( g );
   QgsAbstractGeometry *buffered = engine.buffer( mSymbol.width() / 2., nSegments, endCapStyle, joinStyle, mitreLimit ); // factory
+  if ( !buffered )
+    return;
 
   if ( QgsWkbTypes::flatType( buffered->wkbType() ) == QgsWkbTypes::Polygon )
   {