From c23de083ce854db9d293da0596621d3993be4f04 Mon Sep 17 00:00:00 2001
From: Nyall Dawson <nyall.dawson@gmail.com>
Date: Thu, 17 Mar 2016 17:36:13 +1100
Subject: [PATCH] Setting a property to null in collections removes property

---
 python/core/qgsproperty.sip        | 3 ++-
 src/core/qgsproperty.cpp           | 4 +++-
 src/core/qgsproperty.h             | 3 ++-
 tests/src/core/testqgsproperty.cpp | 6 ++++++
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/python/core/qgsproperty.sip b/python/core/qgsproperty.sip
index 78184b2f88a..a8927b98655 100644
--- a/python/core/qgsproperty.sip
+++ b/python/core/qgsproperty.sip
@@ -630,7 +630,8 @@ class QgsPropertyCollection
      * @param key integer key for property. Any existing property with the same key will be deleted
      * and replaced by this property. The intended use case is that a context specific enum is cast to
      * int and used for the key value.
-     * @param property property to add. Ownership is transferred to the collection.
+     * @param property property to add. Ownership is transferred to the collection. Setting a property
+     * to null will remove the property from the collection.
      */
     void setProperty( int key, QgsAbstractProperty* property /Transfer/ );
 
diff --git a/src/core/qgsproperty.cpp b/src/core/qgsproperty.cpp
index b3334e67a1a..d8cefeada0c 100644
--- a/src/core/qgsproperty.cpp
+++ b/src/core/qgsproperty.cpp
@@ -724,7 +724,9 @@ void QgsPropertyCollection::setProperty( int key, QgsAbstractProperty* property
   if ( hasProperty( key ) )
     delete mProperties.take( key );
 
-  mProperties.insert( key, property );
+  if ( property )
+    mProperties.insert( key, property );
+
   mDirty = true;
 }
 
diff --git a/src/core/qgsproperty.h b/src/core/qgsproperty.h
index 630d508f7ec..dfa1a2e8dbe 100644
--- a/src/core/qgsproperty.h
+++ b/src/core/qgsproperty.h
@@ -718,7 +718,8 @@ class CORE_EXPORT QgsPropertyCollection
      * @param key integer key for property. Any existing property with the same key will be deleted
      * and replaced by this property. The intended use case is that a context specific enum is cast to
      * int and used for the key value.
-     * @param property property to add. Ownership is transferred to the collection.
+     * @param property property to add. Ownership is transferred to the collection. Setting a property
+     * to null will remove the property from the collection.
      */
     void setProperty( int key, QgsAbstractProperty* property );
 
diff --git a/tests/src/core/testqgsproperty.cpp b/tests/src/core/testqgsproperty.cpp
index 7c19d5ad345..ce47353cec9 100644
--- a/tests/src/core/testqgsproperty.cpp
+++ b/tests/src/core/testqgsproperty.cpp
@@ -797,6 +797,12 @@ void TestQgsProperty::propertyCollection()
   QCOMPARE( collection.count(), 2 );
   QCOMPARE( collection.propertyKeys().toSet(), QSet<int>() << Property1 << Property3 );
 
+  //test removing a property
+  collection.setProperty( Property1, nullptr );
+  QVERIFY( !collection.property( Property1 ) );
+  QVERIFY( !collection.hasProperty( Property1 ) );
+  QCOMPARE( collection.propertyKeys(), QList<int>() << Property3 );
+
   //clear
   collection.clear();
   QCOMPARE( collection.count(), 0 );