use a pointer otherwise Python is creating a copy

python/core/__init__.py

@@ -210,6 +210,8 @@ class edit(object):
             self.layer.rollBack()
             return False
 
+# Python class to mimic QgsReadWriteContextCategoryPopper C++ class
+
 
 class ReadWriteContextEnterCategory():
     def __init__(self, context, category_name, details=None):
@@ -227,6 +229,7 @@ class ReadWriteContextEnterCategory():
         return True
 
 
+# Inject the context manager into QgsReadWriteContext class as a member
 QgsReadWriteContext.enterCategory = ReadWriteContextEnterCategory
 
 

python/core/qgsreadwritecontext.sip.in

@@ -116,7 +116,7 @@ This would happen when it gets out of scope.
 #include "qgsreadwritecontext.h"
 %End
   public:
-    QgsReadWriteContextCategoryPopper( QgsReadWriteContext &context );
+    QgsReadWriteContextCategoryPopper( QgsReadWriteContext *context );
 %Docstring
 Creates a popper
 %End

src/core/qgsreadwritecontext.cpp

@@ -41,7 +41,7 @@ QgsReadWriteContextCategoryPopper QgsReadWriteContext::enterCategory( const QStr
   if ( !details.isEmpty() )
     message.append( QString( " :: %1" ).arg( details ) );
   mCategories.push_back( message );
-  return QgsReadWriteContextCategoryPopper( *this );
+  return QgsReadWriteContextCategoryPopper( this );
 }
 
 void QgsReadWriteContext::leaveCategory()

src/core/qgsreadwritecontext.h

@@ -122,10 +122,14 @@ class CORE_EXPORT QgsReadWriteContextCategoryPopper
 {
   public:
     //! Creates a popper
-    QgsReadWriteContextCategoryPopper( QgsReadWriteContext &context ) : mContext( context ) {}
-    ~QgsReadWriteContextCategoryPopper() {mContext.leaveCategory();}
+    QgsReadWriteContextCategoryPopper( QgsReadWriteContext *context ) : mContext( context ) {}
+    ~QgsReadWriteContextCategoryPopper()
+    {
+      if ( mContext )
+        mContext->leaveCategory();
+    }
   private:
-    QgsReadWriteContext mContext;
+    QgsReadWriteContext *mContext;
 };
 
 #endif // QGSREADWRITECONTEXT_H