From 948c9641d378dd9750150b7ec70281627a7bf310 Mon Sep 17 00:00:00 2001
From: nirvn <nirvn.asia@gmail.com>
Date: Wed, 14 Aug 2019 08:13:43 +0000
Subject: [PATCH] [layout] Fix crash an attribute table item tries to access a
 destroyed map

---
 .../layout/qgslayoutitemattributetable.cpp    | 21 +++++++++++++------
 src/core/layout/qgslayoutitemattributetable.h |  4 ++++
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/core/layout/qgslayoutitemattributetable.cpp b/src/core/layout/qgslayoutitemattributetable.cpp
index b4bc414fffd5..f26c500199fe 100644
--- a/src/core/layout/qgslayoutitemattributetable.cpp
+++ b/src/core/layout/qgslayoutitemattributetable.cpp
@@ -224,6 +224,19 @@ void QgsLayoutItemAttributeTable::resetColumns()
   }
 }
 
+void QgsLayoutItemAttributeTable::disconnectCurrentMap()
+{
+  if ( !mMap )
+  {
+    return;
+  }
+
+  disconnect( mMap, &QgsLayoutItemMap::extentChanged, this, &QgsLayoutTable::refreshAttributes );
+  disconnect( mMap, &QgsLayoutItemMap::mapRotationChanged, this, &QgsLayoutTable::refreshAttributes );
+  disconnect( mMap, &QObject::destroyed, this, &QgsLayoutItemAttributeTable::disconnectCurrentMap );
+  mMap = nullptr;
+}
+
 void QgsLayoutItemAttributeTable::setMap( QgsLayoutItemMap *map )
 {
   if ( map == mMap )
@@ -231,19 +244,15 @@ void QgsLayoutItemAttributeTable::setMap( QgsLayoutItemMap *map )
     //no change
     return;
   }
+  disconnectCurrentMap();
 
-  if ( mMap )
-  {
-    //disconnect from previous map
-    disconnect( mMap, &QgsLayoutItemMap::extentChanged, this, &QgsLayoutTable::refreshAttributes );
-    disconnect( mMap, &QgsLayoutItemMap::mapRotationChanged, this, &QgsLayoutTable::refreshAttributes );
-  }
   mMap = map;
   if ( mMap )
   {
     //listen out for extent changes in linked map
     connect( mMap, &QgsLayoutItemMap::extentChanged, this, &QgsLayoutTable::refreshAttributes );
     connect( mMap, &QgsLayoutItemMap::mapRotationChanged, this, &QgsLayoutTable::refreshAttributes );
+    connect( mMap, &QObject::destroyed, this, &QgsLayoutItemAttributeTable::disconnectCurrentMap );
   }
   refreshAttributes();
   emit changed();
diff --git a/src/core/layout/qgslayoutitemattributetable.h b/src/core/layout/qgslayoutitemattributetable.h
index 220a075ad307..f6b9bc7cf71d 100644
--- a/src/core/layout/qgslayoutitemattributetable.h
+++ b/src/core/layout/qgslayoutitemattributetable.h
@@ -299,6 +299,10 @@ class CORE_EXPORT QgsLayoutItemAttributeTable: public QgsLayoutTable
     bool writePropertiesToElement( QDomElement &elem, QDomDocument &doc, const QgsReadWriteContext &context ) const override;
     bool readPropertiesFromElement( const QDomElement &itemElem, const QDomDocument &doc, const QgsReadWriteContext &context ) override;
 
+  private slots:
+
+    void disconnectCurrentMap();
+
   private:
 
     //! Attribute source