From 6d82cd63b69b0ee92caecaf88c6532ca43677784 Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Mon, 15 Aug 2016 09:02:30 +1000
Subject: [PATCH] Fix leak caused by missing virtual destructor

---
 python/core/qgsexpressioncontextgenerator.sip | 2 ++
 src/core/qgsexpressioncontextgenerator.h      | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/python/core/qgsexpressioncontextgenerator.sip b/python/core/qgsexpressioncontextgenerator.sip
index ea5b696edbe..e2ce3cc2348 100644
--- a/python/core/qgsexpressioncontextgenerator.sip
+++ b/python/core/qgsexpressioncontextgenerator.sip
@@ -38,4 +38,6 @@ class QgsExpressionContextGenerator
      * and return an expression context.
      */
     virtual QgsExpressionContext createExpressionContext() const = 0;
+
+    virtual ~QgsExpressionContextGenerator();
 };
diff --git a/src/core/qgsexpressioncontextgenerator.h b/src/core/qgsexpressioncontextgenerator.h
index a5a75aefe01..ed1c5cdd8ef 100644
--- a/src/core/qgsexpressioncontextgenerator.h
+++ b/src/core/qgsexpressioncontextgenerator.h
@@ -43,6 +43,8 @@ class QgsExpressionContextGenerator
      * @note Added in QGIS 3.0
      */
     virtual QgsExpressionContext createExpressionContext() const = 0;
+
+    virtual ~QgsExpressionContextGenerator() {}
 };
 
 #endif // QGSEXPRESSIONCONTEXTGENERATOR_H